4.2 oil consumption

[revamp]

My 02 has 260,000+ on the engine. It drinks oil. I don't get oil drips. I had an aftermarket intake and filter, and I was getting blowback constantly. I was tired of dealing with it, so I put the stock equipment back on so at least it would get caught in the air box and not drip everywhere else. I was consuming oil pretty regularly.

On a slight change of topic, I am not in the process of getting an 07 engine put in, along with an 07 transmission. This is after my transmission went out. Paying about $1950 for parts and labor and fluids. Well worth it to keep the truck and keep dumping money into it. I know engine rebuilds to fix seals and things is not always the most cost effective.

The High Consumption version oil sounds interesting. Any details on what kind of properties it has to help with that kind of situation?

... hopefully I won't have to worry about this topic on my truck when I get it back.

Good luck to you!

 

[IllogicTC]

I have an 06, with 187,000 miles on it, and mine has been eating oil for years. It's either eating it, or leaking it, and if you aren't getting oil spots on your driveway, or smoke from exhaust, you are probably just going to have to live with it without a lot of time and money being spent. GM's "allowed" oil consumption rate is something crazy like 1 quart per 2000 miles!

I have the smoke thing happen as well, I think it's normal. Ever put oil in a frying pan and see it smoke when hot? Unless, it's coming out under pressure, that would indicate a problem though.

You can try switching oil brands, also they do make a "high consumption" kind that may help, I may try that myself.

Or, you can just check your oil on a regular basis and throw a quart in from time to time. Mine has always been a little random, I suspect that certain styles of driving burn more oil up.

The official rate designated in the shop manuals for the GMT360/370 is 1 quart every 3200 miles. That's the absolute maximum tolerance before they'd say you're due for a rebuild or something. I believe the "old engine" or "high-consumption" oils just have additives in them that are supposed to help condition seals or something. Used some in a Ford 351 Windsor that ate oil up, I couldn't honestly tell if it made an appreciable difference on the seal leaks, because it was too busy burning oil thanks to a piston ring or head gasket or something. It could be worth a shot.

 

[JerryIrons]

I've got the paper service manual for mine, GMT/06-STNS-2, engine mechanical 4.2L Section 6-55:

"Excessive oil consumption (not due to leaks) is the use of 0.95L (1.0 qts) or more of engine oil within 2,414 kilometers (1,500 miles)."

Now, do I think it's acceptable to burn 2 quarts of oil every 3,000 miles ? Of course not. But, I think what the manual is saying is that these engines like to burn oil, and having to add a quart isn't all that uncommon, or all that harmful to the engine. The manual may of course be wrong as well, that's never happened LOL.

I've never used the oil with additives (high mileage/high consumption), but once you start using them, you may have to stay on them ?

-Jerry

 

[IllogicTC]

I've got the paper service manual for mine, GMT/06-STNS-2, engine mechanical 4.2L Section 6-55:

"Excessive oil consumption (not due to leaks) is the use of 0.95L (1.0 qts) or more of engine oil within 2,414 kilometers (1,500 miles)."

Now, do I think it's acceptable to burn 2 quarts of oil every 3,000 miles ? Of course not. But, I think what the manual is saying is that these engines like to burn oil, and having to add a quart isn't all that uncommon, or all that harmful to the engine. The manual may of course be wrong as well, that's never happened LOL.

I've never used the oil with additives (high mileage/high consumption), but once you start using them, you may have to stay on them ?

-Jerry

Not sure if you have to stay on them once you start. I think they'd like you to, because money, but the reality may be different.

You have the Helm manuals? I'm going off the manuals provided in the Technical Discussion page here. 3200 seems like a nice tolerance, for those who obsess and do a change every 3000 if it's a quart low it's normal, works out 1500 seems a bit excessive, but maybe that's their definition of excessive oil consumption rather than just oil consumption? I don't know.

 

[JerryIrons]

I can't remember where I got the manuals from, if it was helms or not, I know I bought it right after I bought the vehicle. It's a 3 volume set, and when I open up the front page it says published by north American operations, general motors corporation. It's yellow, and the front has some kind of seal that says authentic technical service information with gm in the middle of it.

Just out of curiosity, I checked my alldata account, which isn't the pro version btw, and they had the same 1500 mile limit. I think you might be right, it's tied into the "excessive" lingo.

-Jerry

 

[IllogicTC]

I can't remember where I got the manuals from, if it was helms or not, I know I bought it right after I bought the vehicle. It's a 3 volume set, and when I open up the front page it says published by north American operations, general motors corporation. It's yellow, and the front has some kind of seal that says authentic technical service information with gm in the middle of it.

Just out of curiosity, I checked my alldata account, which isn't the pro version btw, and they had the same 1500 mile limit. I think you might be right, it's tied into the "excessive" lingo.

-Jerry

You were absolutely right. I was wrong, it's 3200 KILOMETERS (or 2000 miles)

 

[Vicompc]

Just an update on my oil consumption, on my way to work Friday the check engine light started flashing I shut it down and had it towed to the shop. They looked at the engine and proclaimed it dead, the number one cyclinder had 20% compression and the exhaust valve was burned. Needless to say the cost to repair/replace the engine is more than I'm willing to put into the truck is worth so I will be leaving the GMTNation.

I found a 2009 Acadia SLT1 with 77000 on it for 13000 out door with a 3yr 36k bumper to bumper warranty. I figure if the engine went everything else was going right behind it, and I had spent 2500 in the last year in repairs to keep it on the road. I'll miss the trailblazer but this was probbaly the best way to go for me.


I want to say thanks to everyone that has helped me over the years, especially The Roadie.