Oil Consumption

[Stutz427]

05 LeSabre with 90,000 miles. CA car. I drove it from ca to Mi but before I did I replaced the intake gaskets and replaced the upper plenum too. Also the pvc valve. I put protect and restore oil in for the drive to Mi and once here changed it again w same oil. Noticed it used about a quart every 600 miles or so. At that point changed the oil to penzoil high mileage 10 w 30. Still uses about the same amount of oil. No smoke on start up, nor any leaks. Car seems to run fine. I was thinking valve seals but seems low mileage for that. Also rings seem to be long lasting on these engines. So where should I look. Bad pvc valve? Pull the plugs to check? Valve seals?

 

[RD_Atlanta]

Was the oil consumption the same before changing the intake & plenum gaskets?

 

[Stutz427]

Can’t tell, bought the car and immediately took it apart

 

[RD_Atlanta]

It seems to me it must be an anomaly since GM 3.8L engines are not known for oil consumption.
I found the service bulletin below on another forum.

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.

 

[lilpoindexter]

My car is down a quart every 5000 miles. I dont know if im burning it or leaking it....BUT compared to new engines that burn a quart every gas tank, i think im doing great. 2000 lesabre, 165k miles.