2000 SL2 Smoking while Idoling only

[Blind898]

I have a 2000 SL2 with 85k miles on it. It has a smoking problem when idoling and its burn threw abit of oil as well. I notice this prob while sitting in a drive threw. After idoling for 2-5ish mins it would start to smoke. At first it was pooring smoke out as if i had a blown head gasket.I know i dont cuz the oil isnt milky. My coolnt is full too. The smoke is oil burning, a few iv talked to spoted it out as oil. Now it only dos it when i idol for 2-5min give it some gas (but it clears up after a min) or setting it in revers. When i drive down the road after idoling it smokes alil then clears up. Iv done a few things before i notice it start the smoking, heres the time line of things iv done.

Repalced the ECTS
Repalced the Upstream O2 sensor with a NGK one
Few days later
Added Seafoam to half a tank of gas ran to empty then put one tank of high grade gas
Few more days later
Put NGK spark plugs normal gaped to 040 (then i notice the smoke) And i noticed i had oil on the top of my old spark plugs. This is when i noticed the oil problem
day later
Replaced the Valve cover gaskets
Cleaned the throttle body
Few days later
Replaced the PVC valve

The smoking by this time has died down alot but it still smoks while it idols but only when i give it gas. I was told that this could be a cracked or sliped piston ring and would be wasted time and money to get this fix right now. Or i could get some kind of cleaner to poor ontop the pistons and let it sit over night then drive it tomorrow and it would clean out the rings and might fix it if its slipped.

My other issue im having is i think i might be getting rly bad gasmilage. It has a 12.5 gal tank. At most im getting 200miles a tank. Right before i repalced the upstream O2 sensor i was able to pull almost 400 miles off the tank. Anyone know what this could be?

[RC1488]

There was no need to replace the valve cover. The valve cover GASKET is what needs to be replaced and torqued down to 89 INCH lbs in the correct sequence. Oil leaks down into the cylinder wells and then onto the exhaust manifold, thus giving you your smoke.

For gas mileage, gets some real data. Track your mpg over 3 fill ups. They should be consistent if you drive the same route/terrain. Bosh o2 sensors have been known to cause issues. Not sure why you replaced the o2 anyway with only 85K, but if its with a Bosh universal this could be your problem.

[Blind898]

Originally Posted by RC1488

There was no need to replace the valve cover. The valve cover GASKET is what needs to be replaced and torqued down to 89 INCH lbs in the correct sequence. Oil leaks down into the cylinder wells and then onto the exhaust manifold, thus giving you your smoke.

For gas mileage, gets some real data. Track your mpg over 3 fill ups. They should be consistent if you drive the same route/terrain. Bosh o2 sensors have been known to cause issues. Not sure why you replaced the o2 anyway with only 85K, but if its with a Bosh universal this could be your problem.

Sry i ment valve cover gasket. When i took the cover off the gaskets crumbled in my hands =/. I didnt have a torque wrench but i did the best i could to tighten them down and it stoped the leaking on the spark plugs.

For the o2 sensor, thats what i was told too. I just got the car with 84k miles on it and havnt had it for too long. I got the NGK o2 sensor for it. When i had the old one in it that caused the check light to come on, it keep reading it was bad. But i was about to pull almost 400 miles with that one in it.

[travelair]

Originally Posted by Blind898

I have a 2000 SL2 with 85k miles on it. It has a smoking problem when idoling and its burn threw abit of oil as well. I notice this prob while sitting in a drive threw. After idoling for 2-5ish mins it would start to smoke. At first it was pooring smoke out as if i had a blown head gasket.I know i dont cuz the oil isnt milky. My coolnt is full too. The smoke is oil burning, a few iv talked to spoted it out as oil. Now it only dos it when i idol for 2-5min give it some gas (but it clears up after a min) or setting it in revers. When i drive down the road after idoling it smokes alil then clears up. Iv done a few things before i notice it start the smoking, heres the time line of things iv done.

Repalced the ECTS
Repalced the Upstream O2 sensor with a NGK one
Few days later
Added Seafoam to half a tank of gas ran to empty then put one tank of high grade gas
Few more days later
Put NGK spark plugs normal gaped to 040 (then i notice the smoke) And i noticed i had oil on the top of my old spark plugs. This is when i noticed the oil problem
day later
Replaced the Valve cover gaskets
Cleaned the throttle body
Few days later
Replaced the PVC valve

The smoking by this time has died down alot but it still smoks while it idols but only when i give it gas. I was told that this could be a cracked or sliped piston ring and would be wasted time and money to get this fix right now. Or i could get some kind of cleaner to poor ontop the pistons and let it sit over night then drive it tomorrow and it would clean out the rings and might fix it if its slipped.

My other issue im having is i think i might be getting rly bad gasmilage. It has a 12.5 gal tank. At most im getting 200miles a tank. Right before i repalced the upstream O2 sensor i was able to pull almost 400 miles off the tank. Anyone know what this could be?

You have two problems. The first is an oil burning issue. Yes, it could be the rings and most likely is. It could also be worn cylinder linings but that is rare for Saturns. The botom line is that, at idle, oil is building up in your rings without burning off. When you load up the engine, it burns off and you will see smoke out the tailpipe. It actually continues to burn oil while driving, you just won't see it until the rings get really worn. Then it won't stop smoking... ever.

You're looking at rebuilding the engine.

Second, the oil burning has caused your bad mileage by fouling up your EGR valve. Clean that out and you will feel the difference and get back to your normal mileage. But realize it's just going to clog up again.

I've heard it may be possible to re-ring and replace the main/rod bearings without removing the engine. This would be done by dropping the oil pan and working under the car. I've never been able to get a piston out the bottom though due to a ridge in the cylinder. I think though that Saturns don't have this problem.

[saturntech]

Originally Posted by travelair

You have two problems. The first is an oil burning issue. Yes, it could be the rings and most likely is. It could also be worn cylinder linings but that is rare for Saturns. The botom line is that, at idle, oil is building up in your rings without burning off. When you load up the engine, it burns off and you will see smoke out the tailpipe. It actually continues to burn oil while driving, you just won't see it until the rings get really worn. Then it won't stop smoking... ever.

You're looking at rebuilding the engine.

Second, the oil burning has caused your bad mileage by fouling up your EGR valve. Clean that out and you will feel the difference and get back to your normal mileage. But realize it's just going to clog up again.

I've heard it may be possible to re-ring and replace the main/rod bearings without removing the engine. This would be done by dropping the oil pan and working under the car. I've never been able to get a piston out the bottom though due to a ridge in the cylinder. I think though that Saturns don't have this problem.

You have to take the head off to do that

[Blind898]

Im not in the spot to rebuild the motor. Ill prob just deal with the lil smoking deal for now and keep an eye on the oil.

As for the EGRvalve how do you properly clean it?

[travelair]

Clean with carb cleaner. Don't go crazy with it though, use it judiciously and only on the little moving part inside. Wipe the rest out with a rag. I've heard you can damage the valve by soaking it. If there's rubber in it somewhere, that would make sense.

[RC1488]

Do a MMO Soak. I have posted the how-to here before. This can help reduce any oil burning from your stuck oil rings.

[Blind898]

Alright i will look this up. Tyvm for the help.