i bought a 2003 tb a few months ago has been a decent car except all of the terrible mechanical work that was done to it prior to ownership but that i could fill a whole forum with...latest problem happened monday i had over heated it (clutch fan was bad and i put electric fan in had not got the temp sensor switch in yet) i forgot to turn on fan and it was boiling over by time i noticed...i refilled with water and drove the 75 mile round trip to work fine problems started wed on way to work half way there noticed temps climbing stopped short of the advertised 260 coolded an refilled water....noticed bottom of rad was cool...put thermostat in parking lot after work refilled coolant and made it about half way home before temp start to climb and i stopped and refilled water...so thoguth it was fact coolant watered down by now so i drained and added gallon and half antifreeze...on way to work today about half way it heated up agai n refill and makde rest of way...there is no water in oil no oil in water no steam out of exhaust and it runs as good as it has always...i have pulled water pump to see if mabe something stupid i know water pumps dont stop pumping as the way thery are designed but wanted to see maybe impeller is plugged or something...but it was not....radiator seems to be alright and i flushed it out with hose...when i take cap off radiator it does not seem like i am getting much flow through the top hose...i am at a loss as what to do next...i am gonna throw a rad at it maybe a a bucnch of the passages are clogged or somethign any one else have this problem...i had replaced thermostat 3 weeks ago and then again 2 days ago...today when i took out water pumop and seen nothing out of ordinary i took thermostat out again and took the spring and valve (opened up the orginal one) out of the neck and installed it filled it up and made about 15 to 20 miles and it just shot up to boiling over again please hel[
NEED HELP 2003 TB EXT 4.2 overheating
- Thread starter h82loseejr
- Start date
jsheahawk
Member
The bottom of the radiator is the transmission cooler. I had a hard time following your post; did you change the thermostat?
Mounce
Member
Yes he did.
One thing notable is the efan installation. It has been said that our radiators are marginal at best, barely able to handle the heat of the engine. Put efans in and some have issues staying cool.
Did you use a premade kit like from pcmofnc made for our rides? Or did you just slap a single unshrouded fan on there?
I'd swap back to stock fan and see how it goes since that is the only variable that changed.
One thing notable is the efan installation. It has been said that our radiators are marginal at best, barely able to handle the heat of the engine. Put efans in and some have issues staying cool.
Did you use a premade kit like from pcmofnc made for our rides? Or did you just slap a single unshrouded fan on there?
I'd swap back to stock fan and see how it goes since that is the only variable that changed.
i used a dual fan that cam out of a chevy venture it has maybe dual 10 or 12 inch fans and are shrouded....they cover all of rad except the top inch or so airflow is fine more than eneough....the transmission cooler quick fitting ripped the threads out of the cooler itself when i tried changing the fitting becuase of small leak...so i am running external trans cooler...i ordered a new rad...im at a loss with this it really looks to me like there is not a lot of water coming back through the top hose
and something happened on monday the first day it heated because it used to run at 210 solid since i put new thermostat in not move one inch past it with the fan on
HARDTRAILZ
Moderator
- Nov 18, 2011
- 49,665
Years of being around this platform has shown that there is never More than Enough with E-fans. Some work, but far more do not flow enough and have proven to not cool properly. Even "good" quality aftermarket efans are not enough for some.
Are you Dead Certain that you did NOT install the Thermostat ...BACKWARDS?
The OP has provided the Best Clue to explain part of the problem by describing that the prior owner was using less than the necessary 50/50 mix of Distilled Water to Anti-Freeze in the Cooling System. If Plain Tap Water has been used over time... Just like a typical Water Heater... the Boiling Restricted Hot Liquid Plain Water Flow going from the Radiator and Engine Block through the Heater Core will tend to drop particulate matter in the "Ox-Bow" turning points inside of the fluid filled finned coils (3/8" in OD?) where the fluid dynamic slows down the flow in each turn point and thereby... collects as Mineral Scale Deposits... clogging those passages. While not completely obstructing the entire flow of the Coolant... a Clogged Heater Core will not be able to act as a normal heat sink and help to absorb and re-distribute the built-up engine heat load... and can contribute substantially to reducing and restricting the proper flow of Coolant throughout the system.
In some situations... clumps of this built up mineral scale can infrequently break off the inner walls of the tubing and form Gunky Plugs that seriously restrict the Coolant Flow. This problem is always region based...with Ferrous Scale and Magnesium in the Rust Belt and Northern parts of the country ...and Calcium Carbonate type deposits further down south like we experience here in Florida. Its also possible for the Plain Water to attack the Waste Foam Cast Aluminum Engine Block Fluid Passages from the inside...dissolving the metal in the hot liquid water as oxide crystals that can add to the problem of clogging these inner passages. Normally... the approved Anti-Freeze (DEXCOOL...AND NOTHING ELSE...) contains the right additives to prevent this electrolytic phenomena from developing. Plain Tap Water offers no such protections.
The next thing to do is to isolate the Inlet and Outlet at the Heater Core Manifold at the Firewall...and Flush it out...both forward and reverse to test whether the flow is restricted and dump the initial out flow into a screened bucket for examination using Acetic Acid (Distilled Vinegar) for Calcium Carbonate and or whatever is approved in the automotive industry for removing Rust and Magnesium deposits. This might take some time...and the Heater Core should receive a thorough fresh water flushing afterwards...before re-attaching the hoses to complete the Coolant Circuit. It is also likely to involve the Radiator as well...and because of its complexity... it would be better replaced...than boiled out and repaired... unless it is a fully TIG Welded, All Aluminum Radiator.
Here is a Generic Video that Covers How To Flush a Heater Core (at 4:25...watch how plugged up the Heater Core is...and what happens when the clog breaks loose...
) Eric is using "CLR" Calcium, Lime and Rust Remover that he's not allowed to freely advertise for on his Youtube Channel).
...and from one of our very own Members...
The OP has provided the Best Clue to explain part of the problem by describing that the prior owner was using less than the necessary 50/50 mix of Distilled Water to Anti-Freeze in the Cooling System. If Plain Tap Water has been used over time... Just like a typical Water Heater... the Boiling Restricted Hot Liquid Plain Water Flow going from the Radiator and Engine Block through the Heater Core will tend to drop particulate matter in the "Ox-Bow" turning points inside of the fluid filled finned coils (3/8" in OD?) where the fluid dynamic slows down the flow in each turn point and thereby... collects as Mineral Scale Deposits... clogging those passages. While not completely obstructing the entire flow of the Coolant... a Clogged Heater Core will not be able to act as a normal heat sink and help to absorb and re-distribute the built-up engine heat load... and can contribute substantially to reducing and restricting the proper flow of Coolant throughout the system.
In some situations... clumps of this built up mineral scale can infrequently break off the inner walls of the tubing and form Gunky Plugs that seriously restrict the Coolant Flow. This problem is always region based...with Ferrous Scale and Magnesium in the Rust Belt and Northern parts of the country ...and Calcium Carbonate type deposits further down south like we experience here in Florida. Its also possible for the Plain Water to attack the Waste Foam Cast Aluminum Engine Block Fluid Passages from the inside...dissolving the metal in the hot liquid water as oxide crystals that can add to the problem of clogging these inner passages. Normally... the approved Anti-Freeze (DEXCOOL...AND NOTHING ELSE...) contains the right additives to prevent this electrolytic phenomena from developing. Plain Tap Water offers no such protections.
The next thing to do is to isolate the Inlet and Outlet at the Heater Core Manifold at the Firewall...and Flush it out...both forward and reverse to test whether the flow is restricted and dump the initial out flow into a screened bucket for examination using Acetic Acid (Distilled Vinegar) for Calcium Carbonate and or whatever is approved in the automotive industry for removing Rust and Magnesium deposits. This might take some time...and the Heater Core should receive a thorough fresh water flushing afterwards...before re-attaching the hoses to complete the Coolant Circuit. It is also likely to involve the Radiator as well...and because of its complexity... it would be better replaced...than boiled out and repaired... unless it is a fully TIG Welded, All Aluminum Radiator.
Here is a Generic Video that Covers How To Flush a Heater Core (at 4:25...watch how plugged up the Heater Core is...and what happens when the clog breaks loose...
) Eric is using "CLR" Calcium, Lime and Rust Remover that he's not allowed to freely advertise for on his Youtube Channel)....and from one of our very own Members...
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Mooseman
Moderator
When I was running the Venture/Montana efans, it was marginal but never actually overheated. Highest it went was halfway to overheat in 33c (91f) with the A/C on. A/C performance was also marginal while stopped. It would most of the time, go back down when I got moving. Went back to the stock fan with a thermal clutch, no problems since.
I would suspect a bad thermostat.
I would suspect a bad thermostat.
Mounce
Member
Are you Dead Certain that you did NOT install the Thermostat ...BACKWARDS?
The OP has provided the Best Clue to explain part of the problem by describing that the prior owner was using less than the necessary 50/50 mix of Distilled Water to Anti-Freeze in the Cooling System. If Plain Tap Water has been used over time... Just like a typical Water Heater... the Boiling Restricted Hot Liquid Plain Water Flow going from the Radiator and Engine Block through the Heater Core will tend to drop particulate matter in the "Ox-Bow" turning points inside of the fluid filled finned coils (3/8" in OD?) where the fluid dynamic slows down the flow in each turn point and thereby... collects as Mineral Scale Deposits... clogging those passages. While not completely obstructing the entire flow of the Coolant... a Clogged Heater Core will not be able to act as a normal heat sink and help to absorb and re-distribute the built-up engine heat load... and can contribute substantially to reducing and restricting the proper flow of Coolant throughout the system.
In some situations... clumps of this built up mineral scale can infrequently break off the inner walls of the tubing and form Gunky Plugs that seriously restrict the Coolant Flow. This problem is always region based...with Ferrous Scale and Magnesium in the Rust Belt and Northern parts of the country ...and Calcium Carbonate type deposits further down south like we experience here in Florida. Its also possible for the Plain Water to attack the Waste Foam Cast Aluminum Engine Block Fluid Passages from the inside...dissolving the metal in the hot liquid water as oxide crystals that can add to the problem of clogging these inner passages. Normally... the approved Anti-Freeze contains the right additives to prevent this electrolytic phenomena from developing. Plain Tap Water offers no such protections.
The next thing to do is to isolate the Inlet and Outlet at the Heater Core Manifold at the Firewall...and Flush it out...both forward and reverse to test whether the flow is restricted and dump the initial out flow into a screened bucket for examination using Acetic Acid (Distilled Vinegar) for Calcium Carbonate and or whatever is approved in the automotive industry for removing Rust and Magnesium deposits. This might take some time...and the Heater Core should receive a thorough fresh water flushing afterwards...before re-attaching the hoses to complete the Coolant Circuit. It is also likely to involve the Radiator as well...and because of its complexity... it would be better replaced...than boiled out and repaired... unless it is a fully TIG Welded, All Aluminum Radiator.
Here is a Generic Video that Covers How To Flush a Heater Core (at 4;25...watch how plugged up the Heater Core is...and what happens when the clog breaks loose...
...and from one of our very own Members...
You can not install the thermostat backwards in the 4.2. It's built into a housing that only goes on one way.
Yeah... I know ... You're Right...It does comes from the various vendors as a single component... But it is actually MODULAR in its Design... and can be easily taken apart and Re-Assembled Backwards... Or Not At All.
In my experience... if ANYTHING is made and assembled by "The Hand of Man"... there is somebody in the manufacturing food chain who will always figure out some way to put it it all together..."Back-Asswards":
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the ac is not working at the moment and as old as it is i am not gonna put effort or money at trying to revive it as i have the ext tb and its a much bigger system...bigger problems so i just stick with the windows down and 65
no not the first thermostat...not the second one...and as it stands right now i took the spring and valve out of the thermostat housing and it is free flowing (no thermostat)
something happened when i over heated it the first time and i just do not know what it is....MRRSM...i think your theory may be on the right track i ordered a new ac delco rad this morning will be here tuesday in meantime i am gonna take the tank off of my old rad and see if passages are clogged and if are ill install new rad...if they are clear im gonna send rad back and move on to next thing god i hope it is this i need my car for work and stuff...sorry if post was not clear i wrote it last night and was tired and stressed about this
1 installed new thermostat about a month ago same time installed dual electric fans from a venture van...cooled fine for a whole month...never went above 210 with fan on ever i filled system with straight tap water
2. monday i was not paying attention and cruising back road looking for wildlife and it overheated...i cooled it down and refilled system with water...drove to work and back tuesday 80 miles or so with no problem
3 wed morning on way to work about 20 miles in it heated up and i had to let it cool and add water again ended up late for work...after work i changed thermostat in work parking lot as it seemed that the whole radiator was cool except the top tank which was hot. on way home it got hot again...again more water and cool off to get it home...
4 when i got home wed i decided that straight water was causing over heat as boiling point of water is less than with antifreeze and i drained all water and filled it up with gallon and half of full strength antifreeze..drove to my girls house that night about 20 or so miles and temp stayed good...on way to work on thrusday it again overheated by this time i am frustrated and the only possiblility i could think of is the impeller on waterpump (uncommon i know but i have seen impellers fins wore right out) is broken or clogged i bought water pump and pulled old one and it was fine reinstalled it and at this time i took the very first thermostat apart and put it backin with no spring or valve and it drove fine again for about 20 or so miles and then temp shoots up and boils over
and there is NO oil in water and no water in oil....exhaust is not steaming either its not that it loses water as in a leak it boils the water and goes out through overflow....has anyone installed a aftermarket transmission cooler...i tried to switch out the quick connect fittings on the stock tranny cooler and when i took the first one out the threads were gaulled and it pulld them out of the cooler so i installed a aftermarket one in front of the condensor on the passenger side and it wasnt getting much air....i move it up behind the grill on the drivers side and to be honest i am going to try to find another home for it and see if this is the issue if its holding up air from getting to radiator also im taking the condensor off tomorrow...where can i put the cooler that 1 it will fit ( i also have a fan on the cooler) and 2 it can get air...the more i thought about this situation the more i think it may be the trans cooler in the way of rad...although both have fans and id think the fan on the rad alone woudl be eneough...tuesday the stock acdelco radiator will be in so i can hook the stock trans cooler back up then
This would be a good time for anyone who knows the specific parts numbers and locations with diagrams of which Coolant Temperature Sensors are correct for this particular cooling system. The reason I suggest this is because it possible to order new coolant sensors that will thread into the various place on the engine..and not work.
THIS IS IMPORTANT:
WHEN YOU INSTALL THE NEW RADIATOR... AT THE SAME TIME ...REPLACE YOUR RADIATOR CAP WITH A BRAND NEW OEM FACTORY UNIT THAT HOLDS PRESSURE TO 15 PSI BEFORE RELEASING COOLANT TO THE ATMOSPHERE!
THIS IS IMPORTANT:
WHEN YOU INSTALL THE NEW RADIATOR... AT THE SAME TIME ...REPLACE YOUR RADIATOR CAP WITH A BRAND NEW OEM FACTORY UNIT THAT HOLDS PRESSURE TO 15 PSI BEFORE RELEASING COOLANT TO THE ATMOSPHERE!
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i am no novice when it comes to mechanics...far from an expert but i do all my own work and most of my friends...there is not much i cannot fix...this has me stumped though...but the more i think about it i am wondering if the placment of my external trans cooler is causing the issues...i need it to get more air as i have 32s and 3.42 ? gears i think it that ratio anyway its the highest one...the trans was getting a bit hot so i moved it up to directly behind the grill and the more i think about it i think this may have been close to the same time the issues started
thanks for the ideas man i honestly am hoping this will clear it up and that maybe it is blocked passages as you were saying i have too much money into this thing already and cannot afford to put much more into it
@h82loseejr ... On behalf of all who come here to help you... You are Most Welcome...
When it comes to doing complicated repairs of complex and mysterious mechanical problems... no one man or woman has all of the answers. And so the Battlefield here is defined by what YOU are up against...and your ally is the Collective Mind of ALL of the Contributing Members here at GMT Nation who hammer away at the problems from different directions and with various levels of expertise and understanding. So in your case... please know that no one can or will challenge your own personal level for Automotive Repair Acumen.
When some suggestions are made... we may stumble over each other from time to time in our efforts to help out. I am more guilty of this than most of doing this... and so I often have to remind myself that "The Road to Hell... Is Paved With Good Intentions..." and get out of the way of others when their Better Ideas rise to the surface and work to solve what is really going wrong as soon as possible.
The Leader of the Communist Party, Deng Zhou Peng ... was once being challenged by the larger group of his party assembly for looking into using methods involving Capitalism as the means to solve their very serious domestic and economic difficulties. His response to their criticism of his methods was just this:
"I Don't Care if the CAT is BLACK or WHITE... as long as it CATCHES MICE..!"
In much the same way... New Members have that same desperate feeling of just getting exactly what they need ASAP... and so we strive to help out and take away your worries as soon as we can. The present landscape of YOUR Battlefield is unique because we are up against the Elemental Laws of Thermodynamics.
In this case... the fact is that ENERGY (HEAT) always moves from where it is most concentrated... to the places where it is NOT. What we need to discover is what is obstructing the transfer of heat at one or more different locations within the Cooling System and also figure out the subtle side of what is supposed to CONTROL and MANAGE that HEAT Transfer. Here are some observations that might help:
(1) All Cooling Systems follow the Laws of Thermodynamics as CLOSED SYSTEMS.
Something as simple as a Loose Radiator Cap or one that releases pressure too soon will be one problem.
(2) The Medium being used to absorb and re-distribute HEAT ENERGY must be reliable in substance, durability and quantity of FLOW and NOT BOIL OFF PREMATURELY.
Anti-Freeze-slash-Coolant is a PERISHABLE MEDIUM that has a limited shelf life and Operational Period and MUST BE REPLACED WITH FRESH FLUID ON SCHEDULE OR LOSE ITS CHEMICAL STABILITY AND COOLING PROPERTIES OVER TIME. THE DESIGN OF THE GM ATLAS ENGINE REQUIRES ONLY DEXCOOL... NOTHING ELSE SHOULD EVER BE USED (ORANGE...NOT YELLOW OR GREEN) AND NEVER PLAIN WATER.
(3) The Mechanism of HEAT TRANSFER must be RELIABLE and UNOBSTRUCTED.
Incorrectly installing an over-sized Transmission Fluid Cooler IN FRONT of the Radiator may obstruct too much Air Flow. Installing a Modified Front Grill that has Too Little Air Flow ...or having something as simple as a large scrap of Newspaper or a Plastic Bag that is either sucked up in front of or jammed in the inward AMBIENT AIR FLOW CAN CAUSE ANY RADIATOR TO FAIL TO COOL THE HOT FLUID CIRCULATING INSIDE AND DEFEAT THE TRANSFER OF THE ABSORBED HEAT CARRIED INSIDE THE FLUID COLUMN.
(4) The SOURCE of HEAT must NOT PRODUCE MORE ENERGY THAN THE COOLING SYSTEM CAN ABSORB AND DISSIPATE FOR STABLE HOMEOTHERMIC DESIGN.
Something as simple as using an INCORRECT EXHAUST MANIFOLD GASKET AND / OR A SERIOUSLY CLOGGED CATALYTIC CONVERTER CAN CAUSE THE HEAT EXPELLED DURING POST-COMBUSTION INSIDE THE ENGINE BLOCK AND OUT OF THE ENGINE EXHAUST MANIFOLD TO SERIOUSLY RAISE THE TEMPERATURE OF THE ENGINE COMPARTMENT IF THE EXHAUST SHIELD IS NOT INSTALLED. IN SOME CASES... THE WHOLE SYSTEM CAN INVOLVE ITSELF IN A "THERMAL RUNAWAY"... RESULTING IN THE HEAD(S) WARPING AND HEAD GASKET FAILURE.
(5) The subtle SENSOR AND RELAY MECHANISMS must all function in concert with the PCM in order to MANAGE THE SYSTEM DYNAMICALLY and react to environmental and temperature changes that ...CAN VARY DUE TO WEATHER, LATITUDE AND ALTITUDE.
Water boils at 212 Degrees Fahrenheit at 14.7 PSI at Sea Level... BUT IT BOILS SOONER IN THE ROCKY MOUNTAINS AT A LOWER TEMPERATURE AND AIR PRESSURE... AND LATER ON THE BANKS OF THE DEAD SEA AT A HIGHER TEMPERATURE. So the system of Coolant Management must be programmed to consider all of these variables. If there is a BAD TEMP SENSOR...the Cooling Fans may not turn on soon enough and the Engine will overheat. If Incorrect Relays or if the PCM itself is Malfunctioning and yet all of the other Sensors and Relays are in order... the same Performance Failure will occur.
There isn't enough Gold in Fort Knox to cover how expensive trying the solve these problems can get by changing one part of the system after another in a Mad Guessing Game while trying to stumble across a solution. It makes sense to approach the problem systematically and examine each of these areas ...one at a time and not try to use a Shotgun Method to figure out what is going wrong. Starting with the Major Components at this point should eliminate the questions of performance and reliability first...and then examine the backlog of PCM Fault Codes...in particular...in their order of appearance and their cluster points to narrow down the problem. It is paramount that each and every system component be installed and employed EXACTLY AS IT WAS DESIGNED...WITHOUT ANY MODIFICATION!
This Unique Engine works better at Higher Temperatures than most other motors and consequently allows for higher compression ratios using cheaper, lower octane fuels because the motor is designed with the Coolant travelling from the Top Down through the Aluminum Engine Head FIRST...rather than from the Bottom Up. However...this puts the temperature of the Coolant closer to its Boiling Point than ordinary engines experience.. for example ...160 Degrees F for a GM LT-1 350 CID. Consequently... with such a narrow margin for error... this is a system that is very sensitive to Sensor or Relay Failure or Delays in Performance.
Everything that should follow on from this point on deserves to be written down as a Check List and followed as the Means to Manage These Repairs... keeping in mind that more than one issue may be hidden in the mix. An organized and thoughtful approach is more likely to get everything working properly again...and hopefully....much sooner... than later.
When it comes to doing complicated repairs of complex and mysterious mechanical problems... no one man or woman has all of the answers. And so the Battlefield here is defined by what YOU are up against...and your ally is the Collective Mind of ALL of the Contributing Members here at GMT Nation who hammer away at the problems from different directions and with various levels of expertise and understanding. So in your case... please know that no one can or will challenge your own personal level for Automotive Repair Acumen.
When some suggestions are made... we may stumble over each other from time to time in our efforts to help out. I am more guilty of this than most of doing this... and so I often have to remind myself that "The Road to Hell... Is Paved With Good Intentions..." and get out of the way of others when their Better Ideas rise to the surface and work to solve what is really going wrong as soon as possible.
The Leader of the Communist Party, Deng Zhou Peng ... was once being challenged by the larger group of his party assembly for looking into using methods involving Capitalism as the means to solve their very serious domestic and economic difficulties. His response to their criticism of his methods was just this:
"I Don't Care if the CAT is BLACK or WHITE... as long as it CATCHES MICE..!"
In much the same way... New Members have that same desperate feeling of just getting exactly what they need ASAP... and so we strive to help out and take away your worries as soon as we can. The present landscape of YOUR Battlefield is unique because we are up against the Elemental Laws of Thermodynamics.
In this case... the fact is that ENERGY (HEAT) always moves from where it is most concentrated... to the places where it is NOT. What we need to discover is what is obstructing the transfer of heat at one or more different locations within the Cooling System and also figure out the subtle side of what is supposed to CONTROL and MANAGE that HEAT Transfer. Here are some observations that might help:
(1) All Cooling Systems follow the Laws of Thermodynamics as CLOSED SYSTEMS.
Something as simple as a Loose Radiator Cap or one that releases pressure too soon will be one problem.
(2) The Medium being used to absorb and re-distribute HEAT ENERGY must be reliable in substance, durability and quantity of FLOW and NOT BOIL OFF PREMATURELY.
Anti-Freeze-slash-Coolant is a PERISHABLE MEDIUM that has a limited shelf life and Operational Period and MUST BE REPLACED WITH FRESH FLUID ON SCHEDULE OR LOSE ITS CHEMICAL STABILITY AND COOLING PROPERTIES OVER TIME. THE DESIGN OF THE GM ATLAS ENGINE REQUIRES ONLY DEXCOOL... NOTHING ELSE SHOULD EVER BE USED (ORANGE...NOT YELLOW OR GREEN) AND NEVER PLAIN WATER.
(3) The Mechanism of HEAT TRANSFER must be RELIABLE and UNOBSTRUCTED.
Incorrectly installing an over-sized Transmission Fluid Cooler IN FRONT of the Radiator may obstruct too much Air Flow. Installing a Modified Front Grill that has Too Little Air Flow ...or having something as simple as a large scrap of Newspaper or a Plastic Bag that is either sucked up in front of or jammed in the inward AMBIENT AIR FLOW CAN CAUSE ANY RADIATOR TO FAIL TO COOL THE HOT FLUID CIRCULATING INSIDE AND DEFEAT THE TRANSFER OF THE ABSORBED HEAT CARRIED INSIDE THE FLUID COLUMN.
(4) The SOURCE of HEAT must NOT PRODUCE MORE ENERGY THAN THE COOLING SYSTEM CAN ABSORB AND DISSIPATE FOR STABLE HOMEOTHERMIC DESIGN.
Something as simple as using an INCORRECT EXHAUST MANIFOLD GASKET AND / OR A SERIOUSLY CLOGGED CATALYTIC CONVERTER CAN CAUSE THE HEAT EXPELLED DURING POST-COMBUSTION INSIDE THE ENGINE BLOCK AND OUT OF THE ENGINE EXHAUST MANIFOLD TO SERIOUSLY RAISE THE TEMPERATURE OF THE ENGINE COMPARTMENT IF THE EXHAUST SHIELD IS NOT INSTALLED. IN SOME CASES... THE WHOLE SYSTEM CAN INVOLVE ITSELF IN A "THERMAL RUNAWAY"... RESULTING IN THE HEAD(S) WARPING AND HEAD GASKET FAILURE.
(5) The subtle SENSOR AND RELAY MECHANISMS must all function in concert with the PCM in order to MANAGE THE SYSTEM DYNAMICALLY and react to environmental and temperature changes that ...CAN VARY DUE TO WEATHER, LATITUDE AND ALTITUDE.
Water boils at 212 Degrees Fahrenheit at 14.7 PSI at Sea Level... BUT IT BOILS SOONER IN THE ROCKY MOUNTAINS AT A LOWER TEMPERATURE AND AIR PRESSURE... AND LATER ON THE BANKS OF THE DEAD SEA AT A HIGHER TEMPERATURE. So the system of Coolant Management must be programmed to consider all of these variables. If there is a BAD TEMP SENSOR...the Cooling Fans may not turn on soon enough and the Engine will overheat. If Incorrect Relays or if the PCM itself is Malfunctioning and yet all of the other Sensors and Relays are in order... the same Performance Failure will occur.
There isn't enough Gold in Fort Knox to cover how expensive trying the solve these problems can get by changing one part of the system after another in a Mad Guessing Game while trying to stumble across a solution. It makes sense to approach the problem systematically and examine each of these areas ...one at a time and not try to use a Shotgun Method to figure out what is going wrong. Starting with the Major Components at this point should eliminate the questions of performance and reliability first...and then examine the backlog of PCM Fault Codes...in particular...in their order of appearance and their cluster points to narrow down the problem. It is paramount that each and every system component be installed and employed EXACTLY AS IT WAS DESIGNED...WITHOUT ANY MODIFICATION!
This Unique Engine works better at Higher Temperatures than most other motors and consequently allows for higher compression ratios using cheaper, lower octane fuels because the motor is designed with the Coolant travelling from the Top Down through the Aluminum Engine Head FIRST...rather than from the Bottom Up. However...this puts the temperature of the Coolant closer to its Boiling Point than ordinary engines experience.. for example ...160 Degrees F for a GM LT-1 350 CID. Consequently... with such a narrow margin for error... this is a system that is very sensitive to Sensor or Relay Failure or Delays in Performance.
Everything that should follow on from this point on deserves to be written down as a Check List and followed as the Means to Manage These Repairs... keeping in mind that more than one issue may be hidden in the mix. An organized and thoughtful approach is more likely to get everything working properly again...and hopefully....much sooner... than later.
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Mooseman
Moderator
Are you saying you're still running it with straight water? For a short period, that may be fine but in the long term, that is very bad. Water alone has a low boiling point and no lubricants for the water pump. You have to run a minimum 50/50 Dexcool and water. City tap water (no well water) is fine but personally, I use distilled water with the mix. To aid the cooling, you could add to the mix some Water Wetter. Should be available in most parts stores.
i just put water inbecause i was between pays and i still had to install the temp switch for the efans and didnt want to waste the coolant...but i do have a question how much flow should i be getting through the top hose as it does not seem like a lot is coming out of the motor
When you were changing out the various Thermostats... is there any chance that you used Paper Towels or a Shop Rag stuffed up inside the Engine Block to keep too much fluid from leaking out...and either left some remnants in there or completely forgot they were in there? This is not as uncommon an occurrence as you might think possible... more than one Shop Rag has been found on occasion stuffed up inside the large barrel Radiator Hoses where the flow of the coolant met these things and stopped the process of The Coolant Cycle...dead in its tracks.
Also... You might consider investing in an inexpensive Digital Laser Thermometer that can be pointed around various locations to find the points where the transition between very hot areas of the Engine Block Vs. Abruptly Cooler locations can be observed and seek out where the probelem areas are likely to be. For instance... If your newly located Transmission Fluid Cooler is located in front of the Radiator... All of the heat nested inside the cooler will be added into the Radiator as ambient air carries through it to pass on through the Radiator...effectively increasing the Heat Load in the Radiator...and defeating the Heat Transfer inside the Transmission Fluid Cooler...making both function with less ability to dissipate the Heat Load. Harbor Freight sells these for around Twenty Bucks.
Also... You might consider investing in an inexpensive Digital Laser Thermometer that can be pointed around various locations to find the points where the transition between very hot areas of the Engine Block Vs. Abruptly Cooler locations can be observed and seek out where the probelem areas are likely to be. For instance... If your newly located Transmission Fluid Cooler is located in front of the Radiator... All of the heat nested inside the cooler will be added into the Radiator as ambient air carries through it to pass on through the Radiator...effectively increasing the Heat Load in the Radiator...and defeating the Heat Transfer inside the Transmission Fluid Cooler...making both function with less ability to dissipate the Heat Load. Harbor Freight sells these for around Twenty Bucks.
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Mooseman
Moderator
The top hose is the hot fluid coming from the engine but if your thermostat is stuck closed, it might flow little or not at all.
therealsethallen
Member
My honest suggestion for you is to go back to stock with the entire system. New Engine Coolant Temp Sensor, Thermostat, Fan Clutch, Shroud and Fan Blade.
The fan assembly can be had from a junkyard on the cheap.
Clutch- ACDelco 15-40133
Thermostat- Stant 14659/ACDelco 15-11006
Engine Coolant Temp Sensor- ACDelco 213-963
Get yourself some two gallons of distilled water and two gallons of Dex-Cool compliant antifreeze, you'll have plenty left over. The EXT has a different coolant capacity than the SWB trucks. Refer to your manual.
The fan assembly can be had from a junkyard on the cheap.
Clutch- ACDelco 15-40133
Thermostat- Stant 14659/ACDelco 15-11006
Engine Coolant Temp Sensor- ACDelco 213-963
Get yourself some two gallons of distilled water and two gallons of Dex-Cool compliant antifreeze, you'll have plenty left over. The EXT has a different coolant capacity than the SWB trucks. Refer to your manual.
Mooseman
Moderator
I agree with the above except for the clutch. ACDelco (usually) is too expensive. Hayden is the favourite here. Some have had early failures with Dorman.
EDIT
Please re-visit #21 in this Posting for a New Video....
I know that "Changing The Thermostat" probably seems like a trivial repair...but since the video topic is relevant to this matter...for those considering doing a Thermostat Change-Out... This video might give you a heads up as to what you can expect to encounter:
...and here is an Alternative Approach...Arguably easier...?
Please re-visit #21 in this Posting for a New Video....
I know that "Changing The Thermostat" probably seems like a trivial repair...but since the video topic is relevant to this matter...for those considering doing a Thermostat Change-Out... This video might give you a heads up as to what you can expect to encounter:
...and here is an Alternative Approach...Arguably easier...?
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Since i hate reading through threads only to see the person may or may not have resolved their issue but never type back to let others know what the solution was....in the end it was the engine...the first time it overheated it must have cracked the head or headgasket possibly the block...i will do another update after the teardown of the old engine....it has a crack somewhere that leaks the compression into the cooling overpressuring the system pushing water out and then overheated....after a 500 engine...100 in various seals...another 100 in fluids...150 for a cherry picker (small harbor freight that is really too small for the job arm is not long eneough to do it properly but i somehow got it in and out) and a 175 axle disconnect from junk yard (broke the housing trying to seperate from the oil pan(god what was gm thinking)) oh ya i got that down to 125 because the fork was broken but my orginal was good so had enuf parts to put a good one together well anyway the tb is back up and running better than ever...also got my hp tuner in and going to start messing with that...havent done much because my wideband is not in yet and am not going to mess around till i get it...anyone have any good places a novice can look for the basics on tuning?
Since i hate reading through threads only to see the person may or may not have resolved their issue but never type back to let others know what the solution was....in the end it was the engine...the first time it overheated it must have cracked the head or headgasket possibly the block...i will do another update after the teardown of the old engine....it has a crack somewhere that leaks the compression into the cooling overpressuring the system pushing water out and then overheated....after a 500 engine...100 in various seals...another 100 in fluids...150 for a cherry picker (small harbor freight that is really too small for the job arm is not long eneough to do it properly but i somehow got it in and out) and a 175 axle disconnect from junk yard (broke the housing trying to seperate from the oil pan(god what was gm thinking)) oh ya i got that down to 125 because the fork was broken but my orginal was good so had enuf parts to put a good one together well anyway the tb is back up and running better than ever...also got my hp tuner in and going to start messing with that...havent done much because my wideband is not in yet and am not going to mess around till i get it...anyone have any good places a novice can look for the basics on tuning?