oil burning...guru's please respond!!!!

exgmguy · 04-25-2001, 04:46 PM

Here is the problem. My car is burning oil in one cylinder. At idle is does not smoke. If I hold it at high rpm for a while (3000+) it smokes when it comes down to an idle.
I can wing the throtle quickly to redline, and it stops totally. It will idle fine with no smoke.

It does not do this all the time, but has started to do it more lately.

My suspisions are a sticking or broken oil ring, or leaking valve guides or seals. I have tested compression right after shutting the car off after smoking at idle. All cylinders come in at 155-160 psi.

I am hoping it is in the head, (TFS) but with my luck it is a broken ring.

Thanks,

Rob

04-25-2001, 05:04 PM

A good sign of a leaking valve guide/seal is blue smoke on start up after sitting for a while, eg overnight.

Maybe a leak down test will give you a better idea of where the problem lies.

------------------
91 coupe
3.73's,long tubes,2 1/2" exh,ported stock t-body,ProM-77mm
cobra intake,edelbrock heads,B303,1.72 rr's
36lb inj's,tremec, & a Paxton NOVI 2000!!!
11.020 @128.95 on BFG Drag Radials (275/60/15)

exgmguy · 04-25-2001, 05:13 PM

Thanks, How exactly do you perform a leakdown test? I imagine you loosen the intake and exhaust rockers, and fill the cylinder with a certain pressure, then time the rate at which it drops? What would I be looking for exactly?

04-25-2001, 05:35 PM

Actually, you'll need to take it to a shop that has a leak down tester. It will measure the amount of cylinder pressure drop as a percentage (somewhere around 10% is still OK).

The tester pumps air continuously into the cylinder (it's hooked up to a compressor)

Usually, you can hear where the air is escaping, giving you a good idea of where the problem is.

04-25-2001, 04:46 PM	#1
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	oil burning...guru's please respond!!!! Here is the problem. My car is burning oil in one cylinder. At idle is does not smoke. If I hold it at high rpm for a while (3000+) it smokes when it comes down to an idle. I can wing the throtle quickly to redline, and it stops totally. It will idle fine with no smoke. It does not do this all the time, but has started to do it more lately. My suspisions are a sticking or broken oil ring, or leaking valve guides or seals. I have tested compression right after shutting the car off after smoking at idle. All cylinders come in at 155-160 psi. I am hoping it is in the head, (TFS) but with my luck it is a broken ring. Thanks, Rob

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Fed Up W/ My Cd Burning Software	Topless In Texas	Blue Oval Lounge	17	08-17-2002 05:25 AM
PCV blowing oil into my intake..burning oil. Please help	Stang_ROTY	Windsor Power	0	08-13-2001 06:00 PM
Oil Burning	Jeff7477	Windsor Power	1	06-30-2001 07:25 PM
Sorry, Mr. 5.0 cannot respond personally.	Mr 5 0	Windsor Power	0	03-15-2001 08:14 PM
oil burning out of exhaust pipe????	Drew	Windsor Power	4	01-22-2001 09:32 AM

04-25-2001, 05:04 PM	#2
SisuStang Guest Posts: n/a	A good sign of a leaking valve guide/seal is blue smoke on start up after sitting for a while, eg overnight. Maybe a leak down test will give you a better idea of where the problem lies. ------------------ 91 coupe 3.73's,long tubes,2 1/2" exh,ported stock t-body,ProM-77mm cobra intake,edelbrock heads,B303,1.72 rr's 36lb inj's,tremec, & a Paxton NOVI 2000!!! 11.020 @128.95 on BFG Drag Radials (275/60/15)

04-25-2001, 05:13 PM	#3
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	Thanks, How exactly do you perform a leakdown test? I imagine you loosen the intake and exhaust rockers, and fill the cylinder with a certain pressure, then time the rate at which it drops? What would I be looking for exactly?

04-25-2001, 05:35 PM	#4
SisuStang Guest Posts: n/a	Actually, you'll need to take it to a shop that has a leak down tester. It will measure the amount of cylinder pressure drop as a percentage (somewhere around 10% is still OK). The tester pumps air continuously into the cylinder (it's hooked up to a compressor) Usually, you can hear where the air is escaping, giving you a good idea of where the problem is.