NEED HELP Intake hose loose with heavy white smoke out from the engine

[yazan]

Hi. I switched the key to on position (without ruining the engine) then I heard that sound like blown thing. Like pressure leak. Then that heavy white smoke run out from underhood for some seconds.
I found the intake manifold hose was removed from its place (like ot was pushed because of high pressure )and there is some oil ln the lower hose plug.
I reconnected the hose and start the engine. Working fine. But what leads to this?

Thanks

 

[mrrsm]

Sure...

A Sudden Backfire from within any of the cylinders burning residual Fuel and Air that escapes through any open Intake Valves inside of the Engine Head and then passing upwards through the Intake Manifold.

If this occurs, it might build up enough explosive over-pressure to Force the Air Intake Plenum Chamber to push itself loose from the Throttle Body (assuming this is the location you are trying to describe).

Engine Backfires are usually the result of having a seriously mis-timed Motor during the period when the Ignition Timing occurs just BTDC (Before Top Dead Center). In rare cases, if enough Carbon has built up inside of the Combustion Chamber begins to act like a "Glow Plug"... it can act like a candle igniting any residual Fuel and Air left over in the stagnant cylinder(s) once the engine is turned off and with the Intake Valves even slightly opened.

If your Radiator Hoses have THIS Style of Clamps (Spring Steel) and look like THIS:



The Advantages of using them are:

(1) They will NEVER Fail because when properly fitted around the OD of the Rubber Radiator Hoses or Heater Hoses and their nozzle attachment points, the Spring Steel Clamps apply constant, uniform squeezing pressure circumferential, essentially ...FOREVER.

(2) As the Rubber Hoses age and decay or collapse and lose their shaping, the Spring Steel Clamps keep working to close in around such defects and maintain a Good Seal.

But if your Throttle Body Intake, Radiator Hoses and Heater Hoses have THIS Style of Clamps (Stainless Steel, Adjustable) that look like THESE:



The Disadvantages of using this type of Clamp around the Throttle Body Intake Port Flange are:

(1) They can be Under-Tightened.
(2) They can be Over-Tightened.
(3) They have Complex Mechanical Parts that can FAIL from being Bent, Stripped Out or Suffer from Metal Fatigue Fractures within their working parts.

If the problem you describe involves the Radiator, Check the Condition of ANY Radiator and Heater Hose Clamps for the presence of Adjustable Type Hose Clamps and inspect them for looseness or damage.

Check for any conditions of the Engine Over-heating via a Failed Thermostat, Failed Fan-Clutch, Low Radiator Coolant Levels, Failing Water Pump.

 

[yazan]

Sure...

A Sudden Backfire from within any of the cylinders burning residual Fuel and Air that escapes through any open Intake Valves inside of the Engine Head and then passing upwards through the Intake Manifold.

If this occurs, it might build up enough explosive over-pressure to Force the Air Intake Plenum Chamber to push itself loose from the Throttle Body (assuming this is the location you are trying to describe).

Engine Backfires are usually the result of having a seriously mis-timed Motor during the period when the Ignition Timing occurs just BTDC (Before Top Dead Center). In rare cases, if enough Carbon has built up inside of the Combustion Chamber begins to act like a "Glow Plug"... it can act like a candle igniting any residual Fuel and Air left over in the stagnant cylinder(s) once the engine is turned off and with the Intake Valves even slightly opened.

If your Radiator Hoses have THIS Style of Clamps (Spring Steel) and look like THIS:

View attachment 97824View attachment 97825

The Advantages of using them are:

(1) They will NEVER Fail because when properly fitted around the OD of the Rubber Radiator Hoses or Heater Hoses and their nozzle attachment points, the Spring Steel Clamps apply constant, uniform squeezing pressure circumferential, essentially ...FOREVER.

(2) As the Rubber Hoses age and decay or collapse and lose their shaping, the Spring Steel Clamps keep working to close in around such defects and maintain a Good Seal.

But if your Throttle Body Intake, Radiator Hoses and Heater Hoses have THIS Style of Clamps (Stainless Steel, Adjustable) that look like THESE:

View attachment 97826

The Disadvantages of using this type of Clamp around the Throttle Body Intake Port Flange are:

(1) They can be Under-Tightened.
(2) They can be Over-Tightened.
(3) They have Complex Mechanical Parts that can FAIL from being Bent, Stripped Out or Suffer from Metal Fatigue Fractures within their working parts.

If the problem you describe involves the Radiator, Check the Condition of ANY Radiator and Heater Hose Clamps for the presence of Adjustable Type Hose Clamps and inspect them for looseness or damage.

Check for any conditions of the Engine Over-heating via a Failed Thermostat, Failed Fan-Clutch, Low Radiator Coolant Levels, Failing Water Pump.

Thanks for your helpful reply.
The radiator is not involved to what happend today. Rad hoses are ok.
The hose I mean is that at the side of the intake manifold. Image attached
BTY that happened after long driving . Then i stop for minutes and then .. Then it happend .. Without running the engine on. Only turning the key to acc position that runs the dash and dtc and acc.
Thanks again

 

[mrrsm]

Right where the short end of that "Rubber Elbow" Hose attaches horizontally to the Small, Black Plastic Tube positioned slightly off center on the outer Intake manifold Mounting Flange is where the story begins. The longer end of the "Rubber Elbow" gets routed vertically and attaches to the other Black Plastic Tube on the upper outer area of the Intake manifold.

I'd recommend Cleaning Out those Black Plastic Tubes to remove anything that might be blocking off the Blow-By Gas Pressure that is forcing the "Rubber Elbow" Hose off of that Black Plastic Tube. Once it gets opened up, the Intake Suction present inside of the Intake Manifold Runners will once again be able to Draw In those Crankcase Vapors.

That "Rubber Elbow" acts as conduit for guiding Pressurized Crank Case Fumes back through the Air Intake Stream in order to get them "Re-Burned". If that Hose is damaged enough on the ends and cannot hold its Grip onto the Short Black Pipe... You can obtain a replacement using the Part Number shown in the images linked below of a Brand New ACDelco OEM "Rubber Elbow":



To make as complete an explanation as possible of this Oddball Occurrence, there is MORE, so please bear with me:

Thanks to Mr. Ron Kociba's Genius Engineering Team from the GM Atlas Engine Design Section, this may get a little bit confusing so looking at the attached images will help to make more sense of this arrangement.

If you follow the "Hook Up" of that "Rubber Elbow" from one point on the Intake Manifold to another just a Short Distance away... You would NOT be faulted for thinking out loud: "WTF...?"

But just beneath this Fully Assembled Engine ...is a "Hidden Pathway" that acts as a "Vapor Guide" leading from the Lower Inner Crankcase all the way up to the outside areas of the Intake Manifold and it takes a rather Circuitous Route in order to get there:

It Starts off at a position on the Driver's Side of the Engine Block where, slightly off-center, it passes from within the Engine Block's Narrow Passageways, leading up through a Small Rectangular Hole in the Upper Flat Surface of the Engine Block.(Highlighted in Red and Yellow in this image):



... from that position, it passes through that Small Rectangular Hole, clearing the Stainless Steel MLS Head Gasket and leading up to a matching Small Rectangular Hole in a Mirror Image Position in the smooth underside surface of the Driver's Side of the Aluminum Engine Head...



From there... it makes a Right Angle Jog out through the side of the Engine Head Casting Hole (Red Arrow) and ends up matching with yet ANOTHER Small Rectangular Shaped Hole slightly off center in the front surface mounting flange of the Intake Manifold:



From there, it finally exits the Intake Manifold horizontally, protruding outwards as a Small Black Plastic Tube. Look over this area on your own Intake Manifold Mounting Flange for its presence.

THIS is where the Short portion of that "Rubber Elbow" Plugs over that Black Plastic Tube while the longer leg of it angles upwards and plugs into the other Black Plastic Tube on the Upper, Outer Intake Manifold.

The Long and The Short of it is THIS:

IF that Black Plastic Tube has gotten Jammed Up with Vapor Laden Crud fed into it over a long time from deep down inside of the Crank Case, that "Rubber Elbow" will continue to Pop Off the Black Plastic Tube under Excessive Blow-By Gas Pressure until it gets Thoroughly CLEANED OUT with some Solvent and Compressed Air.

Afterwards it will help to submerge the entire Intake Manifold into a Bucket filled with Hot Soapy Water and some Dawn Dish Detergent... .

Better yet, use some "Purple Power" to soak the Damned Thing and then Hose it all out in the Front Yard. Afterwards, use some Compressed Air to get the rest of the water out then allow it to dry out in the Hot Sun before replacing the Three "Figure 8 "O" Ring Style Gaskets and re-installing it later onto the Motor.

Jesus Palomino... I hope that all of this makes sense to you, Brother...

 

[TequilaWarrior]

Thanks for your helpful reply.
The radiator is not involved to what happend today. Rad hoses are ok.
The hose I mean is that at the side of the intake manifold. Image attached
BTY that happened after long driving . Then i stop for minutes and then .. Then it happend .. Without running the engine on. Only turning the key to acc position that runs the dash and dtc and acc.
Thanks again

This is.... odd.
That hose is for PCV (positive crankcase ventilation) and basically supplies VACUUM to the crankcase in order to improve ring seal. That there would be pressure in any place that would cause that hose to blow off is ~strange~ to say the least.

UNLESS - and this is purely conjecture - Unless the upper port the hose was blown off of is/was plugged with something. It is essentially normal for there to be oil in that hose as the vacuum in the intake plenum basically sucks vaporized oil out of the crankcase, through that hose, into the intake plenum to be fed into the cylinders to be burned on the next cycle. The crankcase, when not properly ventilated as just described, will create pressure from "blowby" - pressure in the combustion chambers leaking past the rings - which is normal. PCV evacuates that overpressure improving ring seal and maintaining adequate compression in the cylinders. Without that evacuation, however, the crankcase will be pressurized. My supposition is that the port on the intake plenum that the hose blew off of was plugged with something - perhaps some sludge - and the pressure blew off the hose. Then perhaps the action of the hose blowing off, dislodged the sludge... just a thought.
If everything is running fine after reconnecting the hose... I wouldn't worry about anything.
If you want to diagnose and/or correct any potential problems, removing the entire intake plenum and desludging it as well as the intake ports on the head may be in order. I would also change the intake gaskets and throttlebody gasket as well as cleaning the throttlebody. Since the intake plenum would be off, I'd replace all of the gaskets on the valve cover as well.
If that sounds like more than you're interested in, reinstall the hose and drive...

 

[TequilaWarrior]

Equidistant along that Intake Manifold Flange is a matching Star Shaped Port that exactly matches that same shape that is cast into the Engine Block. That Hose is supposed to allow any Built-Up Blow-By Gas Pressure to pass through that interface.

(I'd recommend Cleaning out that Short Black Plastic Pipe Section molded into the outer Intake manifold to Clear out anything that might be Blocking the Blow-By Gas Pressure and Forcing the Hose off of that extension.)

That "Rubber Elbow" acts as conduit for guiding those pressurized Crank Case Fumes back through the Air Intake Stream in order to get them "Re-Burned". If that Hose is damaged enough on the ends and cannot hold its Grip onto the Short Black Pipe... You can obtain a replacement using the Part Number shown in the images linked below of a Brand New ACDelco OEM "Rubber Elbow":

View attachment 97830View attachment 97831

But to make as complete an explanation of this Oddball Occurrence... There is MORE. Please bear with me... Thanks to Mr. Ron Kociba's Genius Engineering Team from GM Atlas Engine Design Section.. This WILL get a little confusing:

If you follow the "Hook Up" of that "Rubber Elbow" from one point on the Intake Manifold to another just another Short Distance away... You would NOT be faulted for thinking out loud: "WTF...?" . But just beneath the Fully Assembled Engine ...is a "Hidden Pathway" that acts a "Vapor Guide" from the Lower Crankcase all the way up to the Intake manifold. It takes a rather circuitous route to get there, though.

It Starts at a position on the Driver's Side of the Engine Block, slightly Off Center, passing from within the Engine Block's Narrow Passageways, leading through a Small Rectangular Hole in the Upper Surface of the Engine Block, (Highlighted in Red and Yellow):

View attachment 97832

... where one can see a Small Rectangular Hole passing through the Stainless Steel MLS Head Gasket... and Leadining into a Matching Small Rectangular Hole opening in an identical Mirror Image Position into the Engine Head Casting in the smooth underside surface of the Aluminum Engine Head...

View attachment 97834

From there... it makes a Right Angle Jog through the Engine Head Casting Holes on the Drivers's Side of the Engine Block and ends up matching up with ANOTHER Small Rectangular Shaped Hole in the Front Off Center surface of the Black Plastic Intake Manifold:

View attachment 97831

From there it FINALLY Ends from that internal position by protruding outwards as a Small Black Plastic Outer Nozzle emanating from the Outer, Lower Mid-Section of the Black Plastic Intake Manifold Mounting Flange.(Look over this area on your own Intake Manifold Mounting Flange for its presence).

THIS is where the Shorter portion of that "Rubber Elbow" Plugs in....and then it reaches upwards where the OTHER longer leg of the "Rubber Elbow" Plugs Right Back into the Upper Outer Intake Manifold. Please observe these images from my "Flickr-Bucket" very carefully while studying these things and it will begin to make more sense to you:

The Long and The Sort of All this is that IF that Black Plastic Pipe has gotten jammed up with Vapor laden Crud guided into it over a long time from the Lower Bowels of the Crank Case... That "Rubber Elbow" will continue to Pop Off under Pressure until that Tube is CLEANED OUT with some Solvent and Compressed Air.

I would recommend athat afterwards: Dunk the Entire Intake manifold into a Bucket filled with Hot Soapy Water and some Dawn Dish Detergent... Then Hose it out in the Front Yard and allow it to Dry Out in the Hot Sun before replacing the Three "Figure "8" "O" Ring Style Gaskets and re-installing it right back onto the Motor.

Jesus Palomino... I hope tall of his makes sense to you, Brother...

We were apparently typing our responses simultaneously and essentially agree.
My experience cleaning that intake (and valve cover) with ZEP Industrial Purple Degreaser was EXTREMELY positive. I can't rave about it enough. I also can't stress enough that it is REALLY BAD FOR YOU and the environment. But damn, does it cut the grease and my intake manifold was absolutely horrible when I started cleaning it.

 

[mrrsm]

Purple Power poured out into Spacious Plastic Mortar Mixing Deep Pan is a much better Option for cleaning up the Intake Manifold for these reasons:



(1) It is Water Soluble, Non-Toxic and can be used On and Inside of Stoves, Ovens and around Food Serving Locations.

(2) It is virtually FREE of VOCs (Volatile Organic Compounds) and is Non-Offensive for indoor use or within enclosed spaces.

(3) It is completely Bio-Degradable and can even be disposed of through the Sinks and Toilets without harming the Environment.

(4) Don't let its "Mild Exterior" Fool you... Purple Power is ONE VERY Powerful, Carbon and Grease Busting Liquid that is also safe to get on your Bare Skin.

Alternatively, for Outdoor Use ONLY... THIS Gunk Engine De-Greaser will also work just as well... But the Intake Manifold will need a Good Washing in Purple Power and Water afterwards followed up with the same "Washing and Drying" Procedures: