2001 pontiac grand prix gt 3.8 losing oil

[roman1978]

2001 pontiac grand prix gt 3.8 burning oil I have to add oil like every 1000 miles 1 quart its not leaking anywhere. car has about 150k miles.can anyone suggest what it can be.

[richtazz]

How did you determine that it isn't leaking? Not all leaks are easy to see nor do they always end up marking your parking spot.

Do you notice bluish white smoke at start-up and when accelerating? That would indicate the car is burning oil, usually caused by a bad/sticking pcv valve, worn rings, bad valve stem seals, etc...

If no smoke is coming out the exhaust, it may only be leaking while driving and that's why you're not seeing any oil on the ground . Common leak points in the series-II 3800 include valve cover gaskets (especially the rear one), oil pan gaskets and the rear main seal.

[tblake]

I agree with Rich. Pull the plugs and check for sure to see if its being burnt.

I'll bet its that rear valve cover gasket.

[roman1978]

Thank you gyes, when i pull plugs what should i look for to see if its burning oil

[BNaylor]

To be losing that much oil which is highly unusual for the SII 3800 engine you should see puddles on the ground or blue smoke out the exhaust at mainly startup or when accelerating. Start with simple stuff like checking the PCV valve as suggested. Make sure it operates properly and all o-ring seals are there.

What brand, type and weight engine oil are you using? Any blue smoke visible out the exhaust?

[roman1978]

i just had the pcv valve replaced 3 weeks ago and that was when the level was full. I checked few days ago and it was missing about 1 qrt i did not add any because i will go to my mechanick this weekend. I usually put in 10w40
and i dont see any puddles and no blue smoke car runs fine.

[BNaylor]

Even with 150K miles there is no reason to use 10W-40. You should be using 10W-30. Is this regular dino oil or synthetic you use?

Were you losing oil before the PCV replacement?

[roman1978]

I am sorry i use 10w30 and i added 2 qts 10w40 in between oil changes
and now i need oil change and i am low again 1 qrt. I was loosing oil before i changed the PCV valve but lately i am loosing more I used to add 1 qrt
in between oil changes but now its like 3 qrts. I read before on the forum that this can be caused by bad exhoust valve. Could that be true and where is that valve located.

[BNaylor]

It is surprising to see that much oil consumption without seeing it either at the exhaust or on the engine leaking someplace. You might have the mechanic run a cylinder compression test. It could be valves or pistons (rings). On the valves, the valve stem seals. Did you check your cooling system to see if there is any oil in it or the coolant levels are off.