What did you do to your GMT today? [Part II]

[Mike534x]

That is correct! I'll check the kit to see if the appropriate fitting/adapter is in there. So at minimum, the pressure should be 12 PSI at just idle. I don't know for sure if the pick up tube is blocked, but the oil on the dipstick is relatively clean with the 1500 miles on the oil change done via dealer in Oct (prior to purchasing the truck). No hint of gas in the oil from the smell test either.

I am curious on why the dummy gauge wasn't reading 40 PSI with the switch disconnected, because from past readings the gauge should at the very least give the false reading then?

Cleaning the TB is definitely on the list, I wanted to remove the coil packs and inspect the spark plugs to see if a tune up was ever done, and whether the correct plugs were used. I've got Iridiums on hand, so it'll line up perfectly this weekend when working on her. I'm half tempted to pull the VVT solenoid to inspect the screen, to see if it looks like there's any blockage/gunk clogging it or if the screens are missing like most of them are prone to with age.

 

[mrrsm]

In order to minimize "Customer Complaints" with an Oiling System NOT using an Analog Gauge... The Factory Default Reading is always ...40 PSI... @MAY03LT has an extensive series of YouTube Videos where he investigates ALL of these Questions with his Tech 2 AND an Analog Oil Pressure Gauge simultaneously ...with very definitive Step-By-Step outcomes to prove what is really going on here. If you check those out, you can compare your results with his and see other important aspects of this issue.

 

[Mike534x]

That was precisely where I got the idea from! Which is why I'm wondering if there is a short somewhere, because the gauge still read 0 despite the sensor being disconnected (before the reset). Otherwise, the gauge should default back to "40 PSI". But I am still curious getting a mechanical gauge connected to get a true reading, just to confirm if that is the case or not.

 

[mrrsm]

You could use the Wiring Diagram that illustrates the Sensor Leads and their destination to check the Continuity of those wires. It is important to know whether or not the Oil Pressure Sensor receives Power either as 12 Volts DC or 5 Volts DC ...or as in the case of most Piezo-Electric Devices...the registry of ANY Internal Oil Pressure acting upon the Zirconium Diaphragm innards manages to generate its OWN Mild Electric Current ultimately carried through the OPS Harness to the PCM.

That signal would then prompt a Pulse Width Modulated signal up to the IPC Oil Pressure Gauge. If you have a Tech 2 ... you can compel the IPC to perform a Gauge Sweep and observe whether or not the Oil Pressure Gauge is performing properly in an almost *Bench Test* manner. If you follow the Alphabetized Listings of the Specific Key Pad Steps to follow in the "IPC" portion of this amazing Document... these Instructions will make this process that much easier to do:

 

[xavierny25]

Yesterday...Cleaned the throttle body and maf sensor. Installed a cleaned and treated green air filter. I'm having issues with a code p0017 and I have to get it fixed before I have to go in for the annual state inspection.

 

[Mike534x]

Managed to get some work done on the Trailblazer this weekend. @Mooseman and @mrrsm oil pressure is registering roughly 14-15 PSI at idle. Revving her to 3k yielded 72-73. So it could be an idle issue maybe, waiting on a new VVT solenoid to get here. Otherwise, no further warnings popped onto the dash.

So after doing that, I took care of chopping off the old links, and replacing those. Sway bar bushings were shot, but I'll do those another time. Temps were starting to drop just as I finished. Of course, not every job is "finished". After being satisfied with the oil pressure readings/the less clunky rear it was time to grab dinner. Got home, and pulled into the driveway and kept smelling something...familiar followed by a "groan". Oh no....please don't be the power steering line again. Yep. The crap clamp allowed the UPPER steel line to pop free of the rubber hose.

Dremel came out, chopped off a little bit of the line, inserted a 3/8" barb fitting, and slipped on a few 3/8" worm gear clamps and topped it back off. Before/After pics attached. Should be the last thing I have to touch PS line wise *knocks on wood*.

 

[mrrsm]

Re: Post #1,125 for @xavierny25 ...FWIW

If you get the chance to do Testing of the Crankshaft to Camshaft Correlation using any Oscilloscope.... This Information will prove invaluable in Diagnosing the P0017 Code:

Known Good Wave Form of a Crankshaft to Camshaft Comparison...with an explanation:

But THIS is What a a Known BAD Wave Form looks like for the Crankshaft vs, Camshaft :

More information can be found via Post #23 in this Link:

How To Use PICO #2204A & HANTEK #1008C Oscilloscopes

You don't need a Huge Bag of Coins in order to obtain and use an Oscilloscope for performing In-Depth Wave Form Analysis in Automotive Applications on everything from Problematic Electronic Fuel Injection to obtaining accurate Compression Tests to Diagnose Internal Engine Conditions. HANTEK...

gmtnation.com

 

[Mike534x]

Time to track down a short somewhere in the Envoy. Moved it out of the garage yesterday morning with no issues, got into this afternoon to take it for gas/errands and it was completely dead. Ugh...alright, jumped it, and it started it up no problems. Took it for a drive, got home, shut it off and it restarted with no problems. Hooked up the battery tender, and the display is showing the capacity was at 30%.

Hoping to get time this weekend to look at it, its so sporadic that I can't narrow down where its happening. Everything was fine last year with the cold temps we had, and I didn't have this problem. Oddly enough, the gauge cluster stops working partially whenever the battery is disconnected/dead. As in, I'll a working RPM and MPH needle, but gas, temp, voltage, and oil pressure will all read 0/off. ABS, Airbag, and brake light will be illuminated and the "PRND" selector will be lit up and not show the little selector box over what gear the shifter is in. (requires disconnecting the battery a few times before it starts working again). I installed my spare new megafuse earlier, as a precaution that maybe the one in there was the issue.

So my suspicions are either, the cluster has a parasitic draw, or there is a minor fault somewhere causing my gremlins. Wiring harness running alongside the middle half of the center console is pinched/has a minor break somewhere (it was removed by a shop when they replaced the gear shifter), or less likely (and hopefully not) culprit is the BCM....or I've got a module somewhere in the truck that's not shutting off like its supposed to.

 

[Mike534x]

Finally found the short that was causing my Envoy's battery to drain within 2-3 days of sitting.....I hope. After combing through GMTN, and TV I found a few posts about the more "suspect" modules. So, I started unplugging one thing at a time, hoping to narrow down where the parasitic draw was coming from. This included the liftgate module, On-Star, disconnecting my Kenwood HU, unplugging the remote start, and checking periodically throughout the week with a mini-fuse tester to find the culprit. Even went as far as buying a QUICKLYNKS BT2000, which is extremely handy! Constant notifications when near the truck getting info on the batteries health/charge percentage which was super handy to monitor where its been sitting the last few weeks.

Started connecting everything after seeing the drain slow down, and noticed it started up after re-connecting the On-Star module. Alright, interesting. Drove it around for a day or so, parked it, and found the battery totally dead the following day. Odd. Put the battery tender back on, and left it to sit with the quick charge function running. Started her up again, and found the cluster wasn't working again, same as last time. RPM tach worked, nothing else was functioning. Swapped in the rebuilt cluster from my old TB and drove it like normal, left it sitting for a week and the battery stayed charged.

So not only was the On-Star module an issue, the cluster also had a short of some sort causing it to add onto the battery drain. Still keeping an eye on things, but so far so good. The Envoy's cluster was sent out for a rebuild, and we'll see if things are finally fixed.

 

[Mike534x]

Welp that was short lived. Looks the problem lies in the Alternator. Was looking over the charging history, and the batteries capacity from a trip to the city Saturday and I'm seeing the average being 12.3 to 12.8v that it's charging at, with spikes of 14.4 to 14.7 for brief moments. 80% of it was driving, and the rest was idling.

The parasitic drain is gone at least, but it seems that it's a triple whammy if the alternator isn't outputting a consistent charge. Talk about bad odds.

 

[TollKeeper]

@Mike534x Uhmmm... No..

Remember in 2005, GM started using computer controlled alternators. Where the alternators would only turn on during a demand cycle, or a drop cycle. Sitting at 12.3-12.8 is perfectly normal. And the "Spikes" are also normal, as the PCM is commanding the alternator on.

 

[Blckshdw]

When I looked at the time readout, I thought that was minutes, and you meant that was your whole drive. Oops. My battery monitor shows the time stamps along the bottom, so I misread your voltage chart.

 

[Mike534x]

@Mike534x Uhmmm... No..

Remember in 2005, GM started using computer controlled alternators. Where the alternators would only turn on during a demand cycle, or a drop cycle. Sitting at 12.3-12.8 is perfectly normal. And the "Spikes" are also normal, as the PCM is commanding the alternator on.

I did forget that about that....even with the changes, that still seems really of an output. Looks like it's back to testing fuses, and figuring out where the power draw is coming from then. It's just so odd to have the same thing happen again 4 1/2 years later, I'm about to pull my hair out trying to track down the culprit

The only thing I haven't looked at yet, was testing a different ignition switch. I replaced the original back in 2016 after the original was flaking out. Current one is an AC Delco from the batch prior to them discontinuing it.

 

[TollKeeper]

@Mike534x Uhmmm... No..

Remember in 2005, GM started using computer controlled alternators. Where the alternators would only turn on during a demand cycle, or a drop cycle. Sitting at 12.3-12.8 is perfectly normal. And the "Spikes" are also normal, as the PCM is commanding the alternator on.

@Mooseman - I just realized I may be wrong.. I know this is true for the LS V8 engines.. Was this also a thing on the 4.2... He has both, and I am not sure which one he is working on.

 

[Mike534x]

@Mooseman - I just realized I may be wrong.. I know this is true for the LS V8 engines.. Was this also a thing on the 4.2... He has both, and I am not sure which one he is working on.

Sorry Tollkeeper, it's the Envoy with the 5.3. Wasn't sure if I specified it earlier or not.

 

[Mooseman]

It's true for both engines. My 2007 4.2 has it and my 2006 5.3 had it however I thing the 4.2 didn't get it until 2006. I may be wrong though.

 

[Mike534x]

So the PCM is controlling the voltage output on 05 models? I tried looking online, and I've seen the 06+ 360/370s have the charging regulator on the battery terminal, same as the full size trucks. My 05 Avalanche had it, as does my Dad's 06 Yukon. The TB has it as well, but I've never seen it on anything under the 05 model years.

Still currently looking around, and I found a mention of it on the old site but that was pertaining to an 06 TB that noticed the fluctuations. (If I can find all the info, I'll happily post it in the FAQ section for future reference to help out anyone needing it).

 

[TollKeeper]

There's a wire you can cut, or depinn, that will have the alternator running at full power all the time.. but I don't know which one or where

 

[Mooseman]

There's a module attached to the negative battery cable near the battery. The loop measures the draw and adjusts the alternator output. If you unplug that module, the alternator will act like a regular alternator and always put out 14v.

 

[Mike534x]

There's a module attached to the negative battery cable near the battery. The loop measures the draw and adjusts the alternator output. If you unplug that module, the alternator will act like a regular alternator and always put out 14v.

Yeah that's the one I'm referring to! I've only ever seen it on the 06+ 360/370s and the 05+ full size trucks. Since I don't have that regulator module, I assumed that at least until the 05 model year the charging output was still regulated/controlled by the alternator.

Sorry for any confusion, the battery/charging issues I'm sorting out are with the 05 Envoy.

 

[Mooseman]

The old style alternator is kinda controlled by the PCM where it will delay turning it on for a few seconds when starting in extreme cold. I don't think this would any effect on your issue. You could have it tested at a parts store.

 

[Mike534x]

Swung by the shop with a box of donuts, spoke to our buddy that's the Service Manager and they brought the Envoy in and hooked their Snap On tool to test the charging system. So despite the battery showing it was low the alternator would keep cycling between charging and then not charging. They found a reman ACD one in stock from Advanced, and installed it. New one is engaging at 14.6V, and settles around 13.1 to 13.3 at idle.

So the charging issue seems to be solved. Now I'm wondering if the charging regulator/diode on the Remy was bad, and it was maybe contributing to the parasitic drain?

Anywho, I pulled the column apart swapped in the Dorman and put it all back together and will monitor it the next few days. The gearing was off just a pinch, so I'm wondering if the switch could've been the culprit too.

 

[Mike534x]

Welp the battery is bad, went to remove the protective cover and found some nice white chalky stuff coming out of where the top half mates to the batteries body. Its also still discharging without being in the truck, so its probably safe to say a cell or too is bad.

One thing I failed to notice upon purchasing the Everstart, is that Walmart no longer uses East Penn for the Gold line. The serial numbers start with "JC" for Johnson Controls, so that's a bummer. I ended up purchasing a Deka Intimidator AGM off RA, while I sort out trying to get Walmart to warranty the Everstart. Their little handheld tester shows its "good", despite the fact it was half dead when bringing it in.....or the fact you can see the corrosion formed around the upper half.

 

[mrrsm]

Re: Post #1,130... @Mike534x ... Just an FYI (DAMMIT! I should have remembered THIS issue.) BUT... if you have any Alternator go sideways with a Bad Rectifier - Diode Circuit... THIS CAN ALSO CAUSE A PARASITIC DRAIN ON THE BATTERY ...EVEN WITH KOEO ...BECAUSE... IT ACTS LIKE A ONE-WAY-ELECTRICAL VALVE AT ALL TIMES... ASSUMING THAT THE RECTIFIER CIRCUIT IS STILL WORKING PROPERLY, ORDINARILY PREVENTING ANY CURRENT FROM LEAKING FROM THE BATTERY BACK THROUGH THE ALTERNATOR DAMAGED RECTIFIER CIRCUIT AND REACHING A GROUND.

Can a bad alternator cause parasitic draw?

I bought a used 2007 Dodge Ram 1500 a few years ago, and for the first 15 months I had no trouble with parasitic draw or dead batteries or anything - I use one of those 150-Watt AC-to-DC power inverter strip in my center console, plugged into the auxiliary power outlet, so that I can charge...

community.cartalk.com

...and while we're Chatting about Batteries, I found out that my Once New (and seldom used ...but on a Permanent Trickle Charger) AGM Truck Battery is NOT well suited for Maintenance on a Slow Trickle Charging System like the GEL Lead-Acid Batteries use.

So even though I have my Optima (The BIG One) Charger working away on it at this very moment, it may not be able to get "The Thing" to Pull a Lazurus ...and come Back From The DEAD a Second Time.

Then I thought... "Hey... WTH... Let's Order that Bosch 4 Year Bad-Ass AGM Battery, too!" It should arrive via Amazon's FREE S&H around April 4th, 2024. This will give me a chance to finalize the Optima's Charging situation by then and perform an R&R of the Old for the New Bosch AGM Battery if needs be.

I'll be glad to get back to Firing Up my Blue Y2K Silverado once again to Warm Up the Oil & Heat Up the Coolant, just to limber things up inside of my Old Five-Point-Three Liter Engine and keep things running that way ad infinitum. You Know... THIS is what happens to us all once we "Get Old" don't really drive very much anymore... :>(





In the immortal words of President Teddy Roosevelt up on San Juan Hill... "CHARGE!"

PS... While "Getting Old"...SUCKS... It is WAY Out In Front of What Lies Ahead in Second Place (...as in having to Take a Dirt Nap) ;>)

 

[Mike534x]

Re: Post #1.130... @Mike534x ... Just an FYI (DAMMIT! I should have remembered THIS issue.) BUT... if you have any Alternator go sideways with a Bad Rectifier - Diode Circuit... THIS CAN ALSO CAUSE A PARASITIC DRAIN ON THE BATTERY ...EVEN WITH KOEO BECAUSE... IT ACTS LIKE A ONE-WAY-ELECTRICAL-VALVE AT ALL TIMES... ASSUMING THAT THE RECTIFIER CIRCUIT IS STILL WORKING PROPERLY.

Can a bad alternator cause parasitic draw?

I bought a used 2007 Dodge Ram 1500 a few years ago, and for the first 15 months I had no trouble with parasitic draw or dead batteries or anything - I use one of those 150-Watt AC-to-DC power inverter strip in my center console, plugged into the auxiliary power outlet, so that I can charge...

community.cartalk.com

...and while we're Chatting about Batteries, I found out that my Once New (and seldom used ...but on a Permanent Trickle Charger) AGM Truck Battery is NOT well suited for Maintenance on a Slow Trickle Charging System like the GEL Lead-Acid Batteries use.

So even though I have my Optima Charger working away on it at this very moment, it may not be able to get "The Thing" to Pull a Lazurus ...and come Back From The DEAD a Second Time.

Then I thought... "Hey... WTH... Let's Order that Bosch 4 Year Bad-Ass AGM Battery, too!" It should arrive via Amazon's FREE S&H around April 4th, 2024. This will give me a chance to finalize the Optima's Charging situation by then and perform an R&R of the Old for the New Bosch AGM Battery if needs be.

I'll be glad to get back to Firing Up my Blue Y2K Silverado once again to Warm Up the Oil & Heat Up the Coolant, just to limber things up inside of my Old Five-Three Engine and keep things running that way. You Know... THIS is what happens to us all once we don't drive very much anymore... :>(

View attachment 111818
View attachment 111819View attachment 111820


In the immortal words of President Teddy Roosevelt up on San Juan Hill... "CHARGE!"

The old *new* battery still was draining after disconnecting the alternator, but I believe the damage was done to the battery. The new alternator works fantastic, with a healthy output charge. I will say, buying the fancy Battery Tender (model 022-0234-DL-WH) has been a life saver! It does offer a trickle charge mode for AGMs to boot, could be handy too for the ole Silverado

​

 

[mrrsm]

Great Suggestion, Mike! I had the Original "Battery Tender" Brand 3 AMP AGM version perpetually attached to the B+ Post and an Engine Bracket as Ground over the last few years that I just removed this morning... and THIS one is definitely a BIG Step Up in a "Connect It & Forget It..." Battery Maintainer-Conditioner & Trickle Charger! Thanks, Brother!

 

[azswiss]

The right turn signal started acting up yesterday and quit completely today; right side flashers, too. Was able to snag the OEM turn signal/flasher module from Autozone this evening just as they were closing. All good now.

 

[vansmack2]

Got the winter wheels put onto the Trailblazer, gotta drop her back off because Discount Tire isn't balancing the wheels properly. Rear ones are still vibrating when going over 50.

Been having an issue with the ABS warning light popping on and off randomly on the Envoy, recently it's been staying on longer then the other lights during startup. Today it stayed on before shutting off, and back on a few times before staying off. Not sure if there's a flaky ground, or one of the speed sensors on the new hubs aren't registering properly. What a pain.

Mike did you get the ABS light thing fixed? It is often caused by corrosion around the speed sensors. I had that problem on my 2002 TB. I took the two front speed sensors out, cleaned all the rust off, re-installed them, and the problem was gone.

 

[vansmack2]

Okay, Mike... NP... So the outstanding issues and questions to be determined are:

(1) After installing an M16 X 1.5 X 1/4" NPT Adapter and Line leading to an Analog Oil Pressure Gauge...Do the Nominal Oil Pressure Readings fall into being at LEAST 12 PSI when @ an Idle of around 600-650 RPM ...and does the Oil Pressure also RISE to around 65 PSI @ around 3,000 RPM?

(2) If NOT...has the Gerotor Oil Pump Orange Gasket (or the Early Model "Blue" Viton "O" Ring) been Cut or Collapsed enough to cause a Loss of Suction & Vacuum into the Gerotor Oil Pump from the Oil in the Crankcase?

(3) Has the Oil Pump Pick Up Tube (Screen) become so blocked and occluded after ingesting too much Carbon Mung held in place on the Screen by Gas-Gum Lacquer forming from Engine Blow-By occurring in all LL8 High Mileage Motors? If the Dipstick bears a Heavy Odor of PURE Gasoline...it would be very symptomatic of having Trapped Low-Tension Compression Rings around all of the Upper Piston Lands & Grooves. An ACDelco TEC Solvent Treatment (Top Engine Cleaning) can help with this issue.

Yes. I have an 02 TB with the blue o-ring and about 270k miles on it. I was getting that dreaded low oil pressure, and verified with a test gauge that it was low. I dropped the oil pan, took out the pickup tube, and while cleaning it the hard o-ring fell apart. I already had the new o-ring, so I put it on after a very good cleaning. Now that I have everything back together I oil pressure is great. My cheap gauge says it is about 30 on idle and 60 at around 2000. I plan on putting a real gauge in the dash.

Even though my oil pressure is good now it looks like I am going to have to tear the engine apart and replaced that oil stretch timing chain. I was hoping I could wait another year, or two, but I keep getting P0014 and P1345 even though both the camshaft and vvt sensors are new. I just ordered all my necessary parts, gaskets, etc. yesterday.

Anyway, I was not trying to hijack this thread. I just wanted to say that replacing the oil pump o-ring on these I6 engines can fix that problem.

 

[Mooseman]

I once (or twice) had the P1345 and it was just a bad cam phaser. I also replaced the timing chain set but that was just because of the chain tensioner.

How to replace I6 timing chain and tensioner

 

[Mike534x]

Mike did you get the ABS light thing fixed? It is often caused by corrosion around the speed sensors. I had that problem on my 2002 TB. I took the two front speed sensors out, cleaned all the rust off, re-installed them, and the problem was gone.

Fixed it not too long after posting. The "new" Moog hub had a defective speed sensor, was able to see the signal dropping in and out while driving. While it was being warrantied, I bought a Timken and swapped that in and it's been good ever since.

 

[vansmack2]

I once (or twice) had the P1345 and it was just a bad cam phaser. I also replaced the timing chain set but that was just because of the chain tensioner.

How to replace I6 timing chain and tensioner

Well, I am going to replace the chain, guides, tensioner, all 3 sprockets (one is the cam phaser sprocket), etc., everything in there. I have a little over 270k on my TB, so I will just do it all. Parts are on order from Rock Auto. Melling timing chain set, and GM gaskets.

Other than those damn codes my TB is running great. I just put a rebuilt transmission in it. When I went to test drive it I had the low oil pressure, which I fixed, then these codes popped up. I had occasionally got the P0014 before, but it was usually around the time when my oil was due for a change. Now I can't drive more than 30 miles before the codes set the SEL. Time to fix it.

 

[Aroc]

Well, I am going to replace the chain, guides, tensioner, all 3 sprockets (one is the cam phaser sprocket), etc., everything in there. I have a little over 270k on my TB, so I will just do it all. Parts are on order from Rock Auto. Melling timing chain set, and GM gaskets.

Other than those damn codes my TB is running great. I just put a rebuilt transmission in it. When I went to test drive it I had the low oil pressure, which I fixed, then these codes popped up. I had occasionally got the P0014 before, but it was usually around the time when my oil was due for a change. Now I can't drive more than 30 miles before the codes set the SEL. Time to fix it.

Have you tried replacing the camshaft actuator solenoid valve. At 270K miles if truck still has original solenoid valve it's worth a try (recommend oem brand Delphi that came with helical spline cam phasers when first came out in 2002 for best phase angle control). May allow more time to replace stretched timing chain which is a huge job.

 

[Mooseman]

I agree. Timing chain is one of the few things that last on these engines. Sure they stretch but they do usually outlast the engine itself. My chain was basically fine, just the tensioner that failed due to poor maintenance by the previous owner. I would have first suggested the CPAS , then a CASE relearn and then the cam phaser. The is also the cam sensor that can get gummed up that a simple cleaning might resolve the issue. The chain would have been a last resort.

 

[northcreek]

Well I've decided to sell my babied Motorhome and I'm starting high on the price because people will always want to deal and it is cherry. So far I've had two different people come to look but, all they wanted to do was tell me their life story and not even listen to what I was trying to explain and basically wasted my day. Is this a new trend or something? seems like the whole thing was their idea of a day trip. Oh, and I also got another one of those via phone...

21' Damon Hornet- Chevrolet C30 - general for sale - by owner - craigslist

1991 Damon Hornet 21’ class C 60 K miles on Chassis, 6 K miles on Jasper factory rebuilt 5.7 TBI engine installed by Reliable Chevrolet NM. Garage kept, no issues everything works as should, no...

buffalo.craigslist.org

 

[MAY03LT]

On Saturday I did some exploratory surgery on my t10004ad. On Sunday I got her back together and she played some tunes until my jump box noped on out.

 

[mrrsm]

Welcome Back, @MAY03LT ... After taking a peek inside your Top Bench Tool Drawer Tray and seeing all of those Pliers-Clamping Type Tools... MAN... You are Nothing if not an Organized Professional Mechanic. THAT Vertical Stacking idea is something I've never seen or considered doing before. Very Clever:

 

[xavierny25]

View attachment 111888

View attachment 111889

On Saturday I did some exploratory surgery on my t10004ad. On Sunday I got her back together and she played some tunes until my jump box noped on out.

Hello brother! Lol that's the amps talking

 

[vansmack2]

Yes, and I think I posted that earlier, but if not I replaced both the camshaft position sensor on the front of the engine, and the vvt sensor behind the power steering pump. Since I have to do the big job of taking the engine apart I am going to replace the timing chain, etc. as I stated, because I only want to do this once.

Have you tried replacing the camshaft actuator solenoid valve. At 270K miles if truck still has original solenoid valve it's worth a try (recommend oem brand Delphi that came with helical spline cam phasers when first came out in 2002 for best phase angle control). May allow more time to replace stretched timing chain which is a huge job.

 

[mrrsm]

After watching what has GOT to be Two of THE Most Inspiring How To Repair Videos I’ve seen in a LONG Time concerning “How To Replace the A/C Compressor Clutch on the GM Full Size Trucks”...I went ahead and picked up the Clutch Kit shown in these images below … Just In Case… .as the coming Summer Months will Play HOLY HELL in The HEAT down here very soon.



And so, I would rather have this New A/C Compressor Clutch Kit and the Tools to do the Job On Hand… than be caught without them. Just imagine replacing the whole A/C Compressor without performing this MUCH Simpler, Well Described Repair...FIRST. So… Props, Kudos and BRAVO! to The Kid and The Two Women who performed these Tasks and did such a Good Job of memorializing their Work!

THESE Ladies REALLY Know Their STUFF around The Garage!

Their excellent application of that OTC Loaner A/C Clutch Removal Tool prompted me to search around over on eBay and locate THIS Very Gently USED version that normally goes NEW for around $110.00 to $140.00 ...and the one I found was offered for only $88.00. Right at this very moment… I need ALL of the Mechanical Advantage I can get whenever doing jobs like THIS: