bad valve seals?
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TECH Junkie
Joined: Nov 2001
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From: Chi-Town
bad valve seals? drove my car to work yesterday, and was cruising along on the expressway. let off the gas, and a nice ole cloud of smoke followed. when i parked, i checked the oil, and i coulda sworn it looked empty. coworker said the same thing. it puffed smoke (oil) at idle too. after work i was gonna throw some oil in there and baby it home. no smoke on cold start up, and the oil level was fine 
oil pressure is fine. i drive home, and check the smoke at idle once im home, its back. rev it a little and it comes out more. checked the oil, and it looked ok. i didnt have a towel to dry it off, but it looked like half the dipstick was coated to the full mark. im thinking bad valve seals? other thought was pcv valve needed replacing. but from searching it looks like i would have a rough idle with a bad pcv. also people have had their dipsticks shoot out, which i havent. top of the oil filler looks a little gummy (white). makes me thinking somethings not venting properly and some moisture is getting in (could be seperate or related to the smoke). any suggestions? i may tear the valve covers off today, but i really cant do much without a spring compressor.
oil pressure is fine. i drive home, and check the smoke at idle once im home, its back. rev it a little and it comes out more. checked the oil, and it looked ok. i didnt have a towel to dry it off, but it looked like half the dipstick was coated to the full mark. im thinking bad valve seals? other thought was pcv valve needed replacing. but from searching it looks like i would have a rough idle with a bad pcv. also people have had their dipsticks shoot out, which i havent. top of the oil filler looks a little gummy (white). makes me thinking somethings not venting properly and some moisture is getting in (could be seperate or related to the smoke). any suggestions? i may tear the valve covers off today, but i really cant do much without a spring compressor.
Originally Posted by DriveATransAm
top of the oil filler looks a little gummy (white).
Originally Posted by DriveATransAm
no smoke on cold start up....im thinking bad valve seals?
Shawn
Well smoke on decell is under high vacuum conditions. Could be a PCV issue.Check the plugs & see what they look like. Look at the PCV hose & into the intake see if it appears to be sucking oil.Also check the crankcase vent hose from passenger valve cover to throttle body for oil.
I would start there
I would start there
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
started it up yesterday. started to puff a little on startup :-/ checked dipstick for real (got a towel finally lol), down 1 quart since last known level...about 200-300 miles prior. its not real bad, it just looks like when your exhaust is running and its heating up the air up when its cold out, but its 70 degrees out now and shouldnt look like that. it gets worse as the car warms up.
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Every car is going to be rich on startup. Your loosing oil and you see smoke, that means you're burning oil. The most common and obvious culprit is the pcv valve. Valve seals are unlikely unless youve messed with your valves, springs, ect.. Because you say it happens when you let off the gas I would conclude pvc. During your run, the crank is chopping up your oil into a fine mist. This evacuates through the point of least resistance(pcv tube). All that fine mist builds in the tube and when you let off the throttle you will have a high velocity and instant vacuum sucking built up oil and mist through your intake. Do a test, unplug the hose that goes to your pcv valve right before the actual valve. With the car on, you will be able to see the mist evacuating the tube at idle.
My car have been burning a lot of oil ever since the cam and headers. I think its the pcv. When I changed the intake, oil was just dripping out of the runners from getting sucked in off the pcv. One of these days I am going to install a catch can and see if it helps.
It might be the rings. I saw a write up about corvettes and oil consumption. GM admitted that in a light load high rpm situation oil will get past the rings. They changed the piston or rings in the later years to fix the problem. I am afraid thats the problem with my car along with the pcv.
I am gonna try the catch can first and see if it fixes it. If not, maybe its time for a rebuild.
It might be the rings. I saw a write up about corvettes and oil consumption. GM admitted that in a light load high rpm situation oil will get past the rings. They changed the piston or rings in the later years to fix the problem. I am afraid thats the problem with my car along with the pcv.
I am gonna try the catch can first and see if it fixes it. If not, maybe its time for a rebuild.
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
well, i sure hope its the pcv valve. i have the part sitting at the gm dealership, ive just been too busy to stop in and pick it up. i hope thats the problem, an easy fix.
wrencher- its blue.
wrencher- its blue.
The funny thing is that if its the rings it doesnt affect performance. THe rings should seal fine but the oil control is the problem. With an automatic you dont have to lift. Since I granny shift I lift at every shift. If I get bad wheelspin and try and pedal it ... nothing but smoke. The best smokeshow was when I left it in 4th when slowing down from the quarter mile. Nothing but smoke. It was at the level of a james bond smoke out to hide in.
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
well, its not the pcv valve 
picked one up, and threw it in, still does it. old one looked ok to me. little oily, but the valve pushed in and all. it smokes worse when its warm than when its cold. not so noticable at idle, but if you rev it up and let off it smokes a bit. its also extremely hard to tell the oil level when the car is warm. never really had that problem before. the oil doesnt coat the stick nice and even like when its cold. almost makes me think theres an oil problem, or its not draining back down to the pan right. almost like its puddling in the valve covers. i never get a low oil light or low oil pressure though <sigh>
i know my car is running rich right now, but this is defenitly different than before. any other suggestions before i take the valve covers off and change the valve seals?
picked one up, and threw it in, still does it. old one looked ok to me. little oily, but the valve pushed in and all. it smokes worse when its warm than when its cold. not so noticable at idle, but if you rev it up and let off it smokes a bit. its also extremely hard to tell the oil level when the car is warm. never really had that problem before. the oil doesnt coat the stick nice and even like when its cold. almost makes me think theres an oil problem, or its not draining back down to the pan right. almost like its puddling in the valve covers. i never get a low oil light or low oil pressure though <sigh> i know my car is running rich right now, but this is defenitly different than before. any other suggestions before i take the valve covers off and change the valve seals?
Before you get that deep, do me a favor and do a search on "catch can". You will find more info pertaining to the design flaw of gm's pcv system, not the valve itself. There have been many attempts by many people on this board. and even GM, to remedy this problem. GM's answer was a pcv casing, I wouldn't actually call it a valve because all it does is restrict the amount of air through a pinhole. Next GM came out with the ls6 valley cover which evacuates the crank gas through the valley rather than a hose on the valve cover. This seemed like a good fix but some have had no luck. The last thing is an attempt by aftermarket and members here to buld a catchcan, sort of an inline filter to "catch" the oil mist before it enters your intake. This works well, and even a combination of all three cant hurt. So, do what you feel like doing, just search first.
Paul
Paul
Thread Starter
TECH Junkie
Joined: Nov 2001
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From: Chi-Town
i know what a catch can is. if it did it a little, all the time, it could be that, but seeing how it does it at idle, most likely it wouldnt be a pcv problem. not to mention this is a new occurance....20K miles and it just started.
