stumped on my missing oil issue

2001 GT 3.8, 72k

about a month ago, the low oil light comes on, and sure enough, i am low a quart!!! never had a problem or a leak before. no oil on the driveway at all!!! no smoke coming out of the tailpipes!!!! i see a little oil around the valve covers, and i change both gaskets with new ones from zzp. have driven about 1000k since the valve cover gasket/oil change, and i am right on track to be a quart low again!!! i use mobil 1 (not synthetic) oil. please help!!!!
oh ya, changed the pcv also.

Well it's either leaking or burning, or you didn't put enough oil in there to begin with. When you pull your dip stick does the oil look milky? You may have a blown gasket if it does. You could also have worn piston rings. I think it would be a good time to perform a compression test.

Well it's either leaking or burning, or you didn't put enough oil in there to begin with. When you pull your dip stick does the oil look milky? You may have a blown gasket if it does. You could also have worn piston rings. I think it would be a good time to perform a compression test.


it is not milky at all..........just low. as far as the piston rings, if it was burning oil, wouldnt i see at least SOME smoke?


what about a leaking oil pan gasket? if it was leaking out of the oil pan, wouldn't i see the drops on the driveway, or would it only be leaking when i am out driving it? thanks for any suggestions.

If you had a leaking oil pan gasket or rear main seal you would see it on the ground or all over the bottom of the engine and autotransaxle. A quart or more is too much considering your mileage. The SII 3800 is not an oil burning engine but in your case it has to be going somewhere. Have you checked the cooling system for any oil contamination?

If you had a leaking oil pan gasket or rear main seal you would see it on the ground or all over the bottom of the engine and autotransaxle. A quart or more is too much considering your mileage. The SII 3800 is not an oil burning engine but in your case it has to be going somewhere. Have you checked the cooling system for any oil contamination?


the cooling system has never been serviced, i was planning on that this month before the hot texas summer hits. how would i go about checking it for oil? thanks very much for your help.

How does the coolant reservoir look. Any sludge or oily film? Overfull?

Also, with engine cool you can drain some coolant into a container for inspection. Just use the radiator drain petcock located at the bottom left hand side (towards engine).

I had a problem with a 98 GP losing oil. I'd see a puff of smoke when I started it, after it sat for a while. I also noticed that if I opened the oil filler cap with the car running, it would almost stall. After a couple months of frustration, I found the very simple problem: missing PCV valve o-ring.

There is a small o-ring around the PCV valve. There is another larger o-ring about 1.5" in diameter inside the PCV housing. You should check and make sure they are both there. Mine was inadvertently misplaced when the pCV valve was changed.

Without the o-ring, oil was passing through and burning off. Over a few weeks, it amounted to a quart or more.

did you check the return hole's and make sure it's nots staying up in valve covers?? only other thing is valve stim seals....

How does the coolant reservoir look. Any sludge or oily film? Overfull?

Also, with engine cool you can drain some coolant into a container for inspection. Just use the radiator drain petcock located at the bottom left hand side (towards engine).


ok i drained a little fluid over the weekend. it looked old and like it needed a flush, but no oil at all. the reservoir was fine, a little low if anything. someone told me that oil in the coolant would mean a little foam..... i dont know if that is correct or not, but either way there was no foam.

i did check the o-rings to the pcv and they were both there. i reset the pcv and made sure everything was tight. the pcv was changed with an AZ part- maybe i should have used a delco??????


the other thing is that when i start it up in the morning, there is a very short puff of white smoke. could this be oil burning? i thought you would see it all the time if it were burning oil?

thanks again for your suggestions, i am trying every one of them.

Typically, white smoke indicates coolant/water being burned in combustion. A bluish color is oil and black is excess fuel.

One of the other posters suggested the oil being burned through leaking valve guide seals or in a worse case piston rings. You may need to run a compression test. Do you have the original UIM and LIM gaskets? Have a friend follow you in another car to observe what color smoke may be coming out of the exhaust in various driving conditions.

Typically, white smoke indicates coolant/water being burned in combustion. A bluish color is oil and black is excess fuel.

One of the other posters suggested the oil being burned through leaking valve guide seals or in a worse case piston rings. You may need to run a compression test. Do you have the original UIM and LIM gaskets? Have a friend follow you in another car to observe what color smoke may be coming out of the exhaust in various driving conditions.



yes, both gaskets are originals, but i thought only the 97-99's had that problem. i am going to go for a drive tomorrow- 20+ miles- and have my buddy follow. will check back on the smoke.

as far as the compression test, i have the kit from the test on my last car. i hope it doesnt come to that though. and the valve guide seals- i would not be able to tell if they were leaking would i? i would just have to replace and wait and see right?

if i am burning oil, is there an additive that anyone here would recommend such as lucas or the popular "engine restore." thanks

pull the plugs. If you're burning oil, it should be evident from the plugs, especially if you are burning as much as you are loosing.

The white smoke at start up sounds like either a coolant leak (the 01's didn't have the plenum issues the eariler 3800-K's did, but GM still used the same garbage gasket). The coolant will seep past the gasket and be burned off at start-up, or if the smoke is slightly bluish, you may have a valve stem seal leak . A small amount of oil is seeping past as the engine sets, then being burned off at start up. Since you're using oil, I'd suspect the valve stem seals. Lastly, in the PCV housing, in addition to the 2 o-rings,there is a spring that keeps the PCV valve seated. If that spring is missing, the PCV valve could be getting lifted off it's seat and causing your oil consumption.

Here is a link to a picture of the old part number (17113515) for a pcv valve housing repair kit from AC-Delco showing the spring I'm referring to. The new part number is 89017274, and also includes the 2 o-rings.

http://198.208.187.182/internet/ViewPartImage.jsp?acdelcoPartNumber=17113515

The white smoke at start up sounds like either a coolant leak (the 01's didn't have the plenum issues the eariler 3800-K's did, but GM still used the same garbage gasket). The coolant will seep past the gasket and be burned off at start-up, or if the smoke is slightly bluish, you may have a valve stem seal leak . A small amount of oil is seeping past as the engine sets, then being burned off at start up. Since you're using oil, I'd suspect the valve stem seals. Lastly, in the PCV housing, in addition to the 2 o-rings,there is a spring that keeps the PCV valve seated. If that spring is missing, the PCV valve could be getting lifted off it's seat and causing your oil consumption.

Here is a link to a picture of the old part number (17113515) for a pcv valve housing repair kit from AC-Delco showing the spring I'm referring to. The new part number is 89017274, and also includes the 2 o-rings.

http://198.208.187.182/internet/ViewPartImage.jsp?acdelcoPartNumber=17113515


after inspecting the pcv setup, i think the clip mechanism that seats the spring and pcv valve (larger plastic piece with clips as seen in photo) was not completely turned to the point that it "snaps" into position, and thus there was not a good seal in the system. i set it correctly, and let it sit for 3 days. when i started it up, there was no smoke. i think i am still going to get the kit for good measure. but i hope this has solved the missing oil issue. thanks for your help guys