using oil

[johnniep]

my 02 GP GT seems to be going down on oil about a liter every 1200-1500 kms....something it never did before..... always change oil @5000 kms and was never down....intake and top gaskets were replaced 20 months ago and it's dry down around the oil pan and i don't see any leaks above...car has 136000 kms on it..........any ideas???

 

[shawngtp]

Look and see if you have any in your rad or in your overfill bottle.
Are you burning any?

 

[johnniep]

no...the dexcool in the overflow is nice and clear...i painted the exhaust tip with high heat aluminum about 3 weeks ago and they're still nice and clean no residue on them

 

[cerick08GP]

Well, I would continue by checking the rest of the “easy” stuff.
First I would inspect the spark plugs. If they appear fouled with oil you may have a bad valve guide seal.
Also, I’d put in a new PCV valve just to be safe. I’m crazy like that I’ll spend the $2.:th_jester:
Although 3800 engines are not picky on oil, at the next oil change I would start using “high mileage” oil. It has extra seal conditioners that may help you. In fact, I would start using it now as top off oil.:th_thumb-up:

 

[johnniep]

I was planning on switching to the high mileage oil since it's almost time for the 5000k oil change....if a bad valve guide seal was a problem wouldn't you get a puff of smoke when you start it up? ......like some older engines do

 

[Bio248]

yeah, you'd notice it out the tail pipes if you were burning it in some form.

 

[The Chad]

Other things to check...

Is your gas mileage affected
Is your operating temperature different
Have you thoroughly checked over the entire engine's exterior with a flashlight for oil
Did you change to synthetic recently, or did you go back and forth from synthetic to conventional oil

To be a "Captain Obvious" here, that's a lot of oil to dissapear in such a short time. So if you're not noticing leaks or smoke, it must be burning the oil slowly and evenly (seals), right?

 

[johnniep]

still using the Quaker State conv\oil 10w30......i did notice today the the engine temp seemed lower than it usually runs at...chaulked it up to the cooler weather. I took the 3800 cover off the top of the motor all is dry...i never really found the GT that great on fuel. I had a 92 regal gs for 14 years it was far better on fuel...at 100kms\hr the pontiac is @2000 rpms.....the buick would be about1500rpm......the regal ran so fine that replacing it with another 3.8 seemed logical

 

[cerick08GP]

Well, I agree with your logic. :th_thumb-up:
I don’t think many ppl buy any W-body car thinking it’s an eco box.
That being said, IMO for a mid-sized car they get great gas mileage, and the 3800 is the perfect size engine for it.
Quaker State is good oil. I’d stick with it just go with the high mileage blend next time.