Thread: Questions about oil consumption 08 GP Base

Hello,
This is the first oil change on the recently purchased 08 Grand Prix base in my signature. Mileage is 73,250. Oil used- Pennzoil Platinum 5w30. Prior oil unknown, assume conventional. At 3k into the OCI it has consumed 1.5qts. Wondering if this is considered normal for this engine.
Thanks!

GM says 1 quart per 3,000 miles is not anything to worry about.

You could try getting a new PCV valve and see if it helps at all or switch oil brands and see if anything changes.

Not a fan of that platinum oil.

Personally I use a high mileage synthetic... Just my own personal preference

Blends are nice but I've found a lot of engines with conventional oil through the the years tend to be filled with a lot of gunk.

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Pennzoil Platinum is a full syn. I chose it because multiple 3800 UOA's online showed low metals. I normally use Mobil 1 but that showed elevated iron and copper levels.

I found this, think it could be the issue?

Bulletin No.: 05-06-01-035A

Date: October 02, 2007

TECHNICAL

Subject:

L26, L32, L36, L67 Excessive Oil Consumption (Replace Exhaust Valve Stem Seals)

Models:

2005 Buick LeSabre, Park Avenue
2005-2008 Buick Allure (Canada Only), LaCrosse
2006-2008 Buick Lucerne
2005 Chevrolet Impala, Monte Carlo
2005 Pontiac Bonneville
2005-2008 Pontiac Grand Prix

with 3800 Series II, III V6 Engine (VINs 2, 4, K, 1 - RPOs L26, L32, L36, L67)

Supercede:

This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 05-06-01-035 (Section 06 - Engine/Propulsion System).

Condition

Some customers may comment on excessive oil consumption on 3800 Series II and Series III engines. An engine that has excessive oil consumption uses 0.9L (1 qt) of oil or more within 3200 km (2,000 mi).

Cause

This condition may be caused by the retaining ring on the exhaust valve stem seal not securely holding the seal on the cylinder head boss. If this occurs, the exhaust valve stem seal(s) may move off the cylinder head boss and no longer provide a sealing function between the exhaust valve stem and the valve guide.

Correction

Inspection and/or Replacement of Exhaust Valve Stem Seals

Follow the appropriate Service Information for the vehicle you are working on to gain access to cylinder head exhaust valves on both cylinder banks. Remove the engine valve rocker arm covers, the exhaust rocker arms and the exhaust valve springs.

Its possible that is the cause.


On the oil brand part, oil is oil. Pick your posion, the only way to truely get those facts is to do it on your own oil. I run regular conventional oil and it works perfect. I never once cared about the metal content in the oil.

I only gave it as a suggestion to the oil eating problem, but it seems that that TSB might be a cause.

Yeah I agree. The other reason why I went with syn was so I could go all the way with the OLM. Oil is already dirty (looking) at 3k, assume the PO was going the entire 7k+ OLM on dino. I know dirty oil doesn't mean the oil is no good, but its an indication the engine was pretty dirty. I'm hoping thats all it is. Will change the PCV asap.