GM 6.2 liter issues

[redone76]

You have a failing oil pump pickup o-ring. When the oil pressure is higher when warm at idle that it is cold, it is because the O-ring is allowing the pump to suck air, and it's easier to stuck air than oil when the oil is cold and thick. As the oil warms up, it becomes easier for the pump to injest on the suction side and that reduces the tendancy to suck air past the failing O-ring.

That's what I've figured is happening. Just not a quick easy job to do...
Think I should get at it sooner than later? Still have my buddies truck tore down!

 

[boatpi]

Mine is in a Hummer H2, 2008, runs great and it does get the 40PSI when running above idle when warm.

 

[Bigbore500r]

That's what I've figured is happening. Just not a quick easy job to do...
Think I should get at it sooner than later? Still have my buddies truck tore down!

Do you have a 2wd? If so you should be able to just drop the crossmember and pan, and get to it. 4WD is a PITA though

 

[BajaMike]

Do you have a 2wd? If so you should be able to just drop the crossmember and pan, and get to it. 4WD is a PITA though

What is a PLTA?

 

[redone76]

Do you have a 2wd? If so you should be able to just drop the crossmember and pan, and get to it. 4WD is a PITA though

Yes sir. 2WD. Gotta take the pan off my buddies truck so I'll see what it'll take before I tackle mine

 

[Bigbore500r]

What is a PLTA?

Pain In The Ass

 

[LargeOrangeFont]

What are you guys running for oil pressure, mine gets down to about 25 pounds on idle once it’s warm?

In the desert that is normal. What car specifically?

 

[Bigbore500r]

Mine is in a Hummer H2, 2008, runs great and it does get the 40PSI when running above idle when warm.

Alot of the aluminum block motors run in the 20-30lb range at base idle speed, whether it's a vette, truck, etc. The Iron block motors usually hold stronger oil pressure at idle when warm. Why? I have no concrete Idea, i've heard it is due to different expansion rates of Iron vs Aluminum and how that affects the oil passages and flow. Same part number for the oil pump so you can take that out of the equation. Doesn't hurt anything. Should jump up over 40lbs by 1200rpm

 

[LargeOrangeFont]

Yes sir. 2WD. Gotta take the pan off my buddies truck so I'll see what it'll take before I tackle mine

Its not too bad. You might need a lifting bar to get the engine up an inch or two. Iv'e never done that in a truck, just a car.

 

[Bigbore500r]

Its not too bad. You might need a lifting bar to get the engine up an inch or two. Iv'e never done that in a truck, just a car.

They have 4 bolts and the front crossmember comes out, super easy with 2wd.

 

[LargeOrangeFont]

They have 4 bolts and the front crossmember comes out, super easy with 2wd.

Shiiiiiit that is a 1 beer job.

To put it in Ford Mustang terms, that is a 2 sidewalk pedestrian deaths job.

 

[redone76]

Do you have a 2wd? If so you should be able to just drop the crossmember and pan, and get to it. 4WD is a PITA though

Thanks for the help bud. Took me about an hour and a half to replace the o-ring. Pressure went straight to 40psi at cold start

 

[redone76]

The 40k GVWR Tru-Cool is a solid unit. Obviously overkill but it knocks the temps down very well. Universal fit, you may need a few adaptor fittings to get it to mate to your factory quick-disconnect trans lines.

https://www.amazon.com/Tru-Cool-LPD4739-4739-Pressure-
Transmission/dp/B00803CTDA

And another thanks for the tip on this trans cooler. Got it installed today. Just waiting on the factory GM trans fittings. Don’t want to cut the lines if I don’t have too. Almost comical the difference in size!

 

[redone76]

Gave the radiator a blow job too. Before pic

 

[Bigbore500r]

View attachment 810489 View attachment 810488

View attachment 810488
And another thanks for the tip on this trans cooler. Got it installed today. Just waiting on the factory GM trans fittings. Don’t want to cut the lines if I don’t have too. Almost comical the difference in size!

Awesome, glad that fixed it up! I wonder how many people end up replacing a motor instead of a $3.00 O-ring....

The trans temps will be drastically lower, should help out the engine cooling too when it’s working hard

 

[redone76]

After. I can actually see through it now. Amazing how much crap blew out!

 

[redone76]

Awesome, glad that fixed it up! I wonder how many people end up replacing a motor instead of a $3.00 O-ring....

The trans temps will be drastically lower, should help out the engine cooling too when it’s working hard

No shit! The oil was the most expensive thing for the job! I’m looking forward to seeing the temp differences.

 

[Runs2rch]

No shit! The oil was the most expensive thing for the job! I’m looking forward to seeing the temp differences.

Is that a lpd True Cool transmission cooler?

 

[BajaMike]

My Denali has the 6.2. I love this engine and it has always been a beast towing my 24 wakeboat until last weekend. All the sudden this thing is heating up. If I turn off the AC it cools down. Does the compressor have that much drag? Or maybe it’s going bad? The truck has 100,000 miles on it so it’s probably due for a coolent flush, plugs etc. any other thoughts or common issues with these motors?

Don’t change the plugs unless it tests as a problem with the plugs. Traditional “tune ups” are not necessary. My 2001 2500 Hd Crew with 180,000 miles has original plugs and runs perfect. Never heats up, towing with A/C and up the grapevine or out I-t0 to Havasu, 200 degrees on the trans temp at the most.

 

[Runs2rch]

Don’t change the plugs unless it tests as a problem with the plugs. Traditional “tune ups” are not necessary. My 2001 2500 Hd Crew with 180,000 miles has original plugs and runs perfect. Never heats up, towing with A/C and up the grapevine or out I-t0 to Havasu, 200 degrees on the trans temp at the most.

I hate to break it to you, but yes traditional tune ups are still needed.

Platinum plugs and factory wires are good to 80-100k optimally.

Pull your plugs. At 180k I guarantee they are blown open. Wires are done also. Cheap 100 bucks.

 

[Big B Hova]

Just bought new knock sensors, cam sensor, and O2 sensors for my 1999 single cab. Pulling intake off tomorrow to swap out the cam and knock sensors.

 

[redone76]

Yes sir. I bought the one bigbore500 linked but without the thermal bypass. $122 on Amazon

 

[LargeOrangeFont]

I hate to break it to you, but yes traditional tune ups are still needed.

Platinum plugs and factory wires are good to 80-100k optimally.

Pull your plugs. At 180k I guarantee they are blown open. Wires are done also. Cheap 100 bucks.

This.

 

[BajaMike]

I hate to break it to you, but yes traditional tune ups are still needed.

Platinum plugs and factory wires are good to 80-100k optimally.

Pull your plugs. At 180k I guarantee they are blown open. Wires are done also. Cheap 100 bucks.

So if my truck hauls ass, tows great, gets good mileage, never gets hot (I live in the desert), and the tech puts the computer on it and no errors in the ignition system, I need new spark plugs and wires?

I don’t get that logic. “If it ain’t broke....don’t fix it”.

 

[Bigbore500r]

So if my truck hauls ass, tows great, gets good mileage, never gets hot (I live in the desert), and the tech puts the computer on it and no errors in the ignition system, I need new spark plugs and wires?

I don’t get that logic. “If it ain’t broke....don’t fix it”.

Computer or diagnostic software doesn’t see the condition of your plugs. It can only detect a blatant misfire. Performance has probably degraded over time and your seat of the pants meter can’t detect it. Probably runs good, but would run better with fresh plugs

 

[BajaMike]

Ok, good info......not driving it much now but planning a long trip in the spring. Probably a good time to do that before I go.

Is there a better than average brand of plugs and wires you recommend?

 

[LargeOrangeFont]

So if my truck hauls ass, tows great, gets good mileage, never gets hot (I live in the desert), and the tech puts the computer on it and no errors in the ignition system, I need new spark plugs and wires?

I don’t get that logic. “If it ain’t broke....don’t fix it”.

Do you change the tires when they are worn out, or just wait to have a blowout?

I guarantee you it will feel more crisp if you change the plugs at 180k miles, and throw on some new wires while you are there.

 

[LargeOrangeFont]

Ok, good info......not driving it much now but planning a long trip in the spring. Probably a good time to do that before I go.

Is there a better than average brand of plugs and wires you recommend?

I like NGK plugs. AC Delco replacement wires will be fine.

 

[BajaMike]

Do you change the tires when they are worn out, or just wait to have a blowout?

I guarantee you it will feel more crisp if you change the plugs at 180k miles, and throw on some new wires while you are there.

I wouldn’t drive out the driveway in my two cars and my truck without good Michelin tires on all four wheels.....but I get your point.

 

[Big B Hova]

Do you change the tires when they are worn out, or just wait to have a blowout?

I guarantee you it will feel more crisp if you change the plugs at 180k miles, and throw on some new wires while you are there.

Amazon you can get factory plugs and wires for around 75 bucks

 

[Bigbore500r]

I like NGK plugs. AC Delco replacement wires will be fine.

Definitely stay with factory wires. #1 cause of misfire codes and ignition issues at my buddies GM tuning / speed shop is “customer installed MSD wires”. He’s gotten to the point that he won’t even bother diagnosing the car anymore if it comes in with those wires. He tells them to get rid of them and come back if there’s still a problem, or just pay him to swap them on the spot

 

[LargeOrangeFont]

Definitely stay with factory wires. #1 cause of misfire codes and ignition issues at my buddies GM tuning / speed shop is “customer installed MSD wires”. He’s gotten to the point that he won’t even bother diagnosing the car anymore if it comes in with those wires. He tells them to get rid of them and come back if there’s still a problem, or just pay him to swap them on the spot

I’ve never been a fan of those MSD wires. I’m running Taylor wires on my RX7 now because it has headers. They are great so far, with plenty of header clearance.

 

[Bigbore500r]

I’ve never been a fan of those MSD wires. I’m running Taylor wires on my RX7 now because it has headers. They are great so far, with plenty of header clearance.

Yea sometimes you don’t have a choice and have to run aftermarket

 

[Racey]

They run these motors hot to help meet the emissions requirements. Like pronstar says If it has a 15lbs cap on the system it raises the boiling point of water to 250F.

That being said, it doesn't take much to go from 235 to 250, at about 255 with antifreeze its going to start to flash boil and it's instantly game over at that point. You're water pump starts to loose a little efficiency from age, or the radiator looses some efficiency and all of a sudden a few percent here and there puts you at the brink of an overheat.

235 is normal believe it or not. I'm not a huge fan of it, but it is what it is.

 

[LargeOrangeFont]

They run these motors hot to help meet the emissions requirements. Like pronstar says If it has a 15lbs cap on the system it raises the boiling point of water to 250F.

That being said, it doesn't take much to go from 235 to 250, at about 255 with antifreeze its going to start to flash boil and it's instantly game over at that point. You're water pump starts to loose a little efficiency from age, or the radiator looses some efficiency and all of a sudden a few percent here and there puts you at the brink of an overheat.

235 is normal believe it or not. I'm not a huge fan of it, but it is what it is.

Yep exactly.

 

[Runs2rch]

I like NGK plugs. AC Delco replacement wires will be fine.

This. I run NGK iridium.

Pulled a set out of a 203k mile 2012 5.3. All blown open to 52-60 thousandths.

 

[Justfishing]

So if my truck hauls ass, tows great, gets good mileage, never gets hot (I live in the desert), and the tech puts the computer on it and no errors in the ignition system, I need new spark plugs and wires?

I don’t get that logic. “If it ain’t broke....don’t fix it”.

Pretty simple. The plugs wear and the gap widens. The spark is weaker. the wider gap increases resistence and your coils are more likely to fail.

If a belt is frayed or a hose is bulging do you keep running it because it had not totally failed.

 

[BajaMike]

Pretty simple. The plugs wear and the gap widens. The spark is weaker. the wider gap increases resistence and your coils are more likely to fail.

If a belt is frayed or a hose is bulging do you keep running it because it had not totally failed.

I replaced the radiator and water pump and serpentine belts at about 150k. Replaced the a/c compressor and condenser a few months later. I’ll fix it when or before its broke.

I’ve just had bad experiences in cars, trucks and one boat, when they said I needed a “tune up”, they would fuck up the vehicle, wrong firing order, wrong plugs, wrong wires........ran worse after “tune up”. Yes, fucked up mechanics, never went back....but I cringe when someone says “tune up” when my truck is running perfect.

 

[Justfishing]

I replaced the radiator and water pump and serpentine belts at about 150k. Replaced the a/c compressor and condenser a few months later. I’ll fix it when or before its broke.

I’ve just had bad experiences in cars, trucks and one boat, when they said I needed a “tune up”, they would fuck up the vehicle, wrong firing order, wrong plugs, wrong wires........ran worse after “tune up”. Yes, fucked up mechanics, never went back....but I cringe when someone says “tune up” when my truck is running perfect.

I would say you have trouble with incompetent mechanics. I have an f150 with close to 300k miles. The truck runs and starts fine. The plugs had abot 90k on them. I pulledthem out to change them. Normal looking plugs but the gap was opened considerably from specs. Didnt notice a great change in performance or mpg but did get a little bump. I did get peace of mind by being able to read the plugs and not see any abnormalities. I also dont wait to change filters until something is wrong.

 

[redone76]

Awesome, glad that fixed it up! I wonder how many people end up replacing a motor instead of a $3.00 O-ring....

The trans temps will be drastically lower, should help out the engine cooling too when it’s working hard

Just an update on the transmission cooler. With the factory cooler I'd see 230 degrees towing my trailer up highway 138 into Phelan while heading to El Mirage. Made the drive a couple weeks back and it didn't break 180 degrees. Engine temp got to 225 but cooled right off when I exited the highway. Towed to Oceanside last week and the trans stayed around 145-150 depending on traffic. Thanks again for the recommendation on this cooler...couldn't be happier!