Smoking at hot idle?
Posted: January 4th, 2013, 12:38 am
Car : 1987 Yugo GV
Engine: Fiat 1500cc
Turbo : T25 (from a wrecked Saab 9000)
My Yugo has developed this weird oil burning issue which started back in September. When this occurs:
1) After the engine has reached normal operating temperature
2) 30 seconds to 1 minute after stopping
3) Does not seem to smoke while going down the road, or under full boost
4) Does not smoke on a cold start
I finally pulled the T25 off my Yugo yesterday. Unlike the T3 that failed on my Spider, I have found no excess amounts of oil in either the compressor or the exhaust discharge. Nor is there any excessive shaft play.
The carbon buildup does feel different between the exhaust manifold collector and the discharge pipe. What is in the discharge pipe just feels softer. What I am trying to determine is I am feeling burnt oil or simply carbon buildup.
So other than that, I can't tell if the oil burning is from a leaking turbo seal or something related to the engine itself.
So assuming the oil burning is not related to the turbo seal, oil backing up in the drain hose from excessive backpressure in the crankcase, restrictive air cleaner, etc. what else would cause the engine to start smoking at normal operating temperature?
Normally a car will smoke when first cranked (say from leaking valve seals or worn rings) but will stop once it's warmed up and everything expands.
This car does not smoke when cold but after it's reached normal operating temperature. Also if I stop and get out and look at the tailpipe, I don't see smoke initially. It usually takes 30 seconds to a minute before it starts smoking while I am letting the turbo wind down.
That leads me to beleive the delay has something to do with oil puddling in the exhaust from a leaking turbo. Also I did not see any oil deposits on the spark plugs so that leads me to believe oil is being burnt in the exhaust system and not the combustion chamber.
I have a rebuild kit and figure it will be easier to rebuild the turbo before rebuilding the engine or even rebuilding the cylinder head. So I'm going to try this first.
This problem did not start progressively. It just cropped up one day back in September.
I supose another idea might be to let the engine run while the turbo is off the car and see if it smokes that way. Be sure to cap off the oil feed hose.
Engine: Fiat 1500cc
Turbo : T25 (from a wrecked Saab 9000)
My Yugo has developed this weird oil burning issue which started back in September. When this occurs:
1) After the engine has reached normal operating temperature
2) 30 seconds to 1 minute after stopping
3) Does not seem to smoke while going down the road, or under full boost
4) Does not smoke on a cold start
I finally pulled the T25 off my Yugo yesterday. Unlike the T3 that failed on my Spider, I have found no excess amounts of oil in either the compressor or the exhaust discharge. Nor is there any excessive shaft play.
The carbon buildup does feel different between the exhaust manifold collector and the discharge pipe. What is in the discharge pipe just feels softer. What I am trying to determine is I am feeling burnt oil or simply carbon buildup.
So other than that, I can't tell if the oil burning is from a leaking turbo seal or something related to the engine itself.
So assuming the oil burning is not related to the turbo seal, oil backing up in the drain hose from excessive backpressure in the crankcase, restrictive air cleaner, etc. what else would cause the engine to start smoking at normal operating temperature?
Normally a car will smoke when first cranked (say from leaking valve seals or worn rings) but will stop once it's warmed up and everything expands.
This car does not smoke when cold but after it's reached normal operating temperature. Also if I stop and get out and look at the tailpipe, I don't see smoke initially. It usually takes 30 seconds to a minute before it starts smoking while I am letting the turbo wind down.
That leads me to beleive the delay has something to do with oil puddling in the exhaust from a leaking turbo. Also I did not see any oil deposits on the spark plugs so that leads me to believe oil is being burnt in the exhaust system and not the combustion chamber.
I have a rebuild kit and figure it will be easier to rebuild the turbo before rebuilding the engine or even rebuilding the cylinder head. So I'm going to try this first.
This problem did not start progressively. It just cropped up one day back in September.
I supose another idea might be to let the engine run while the turbo is off the car and see if it smokes that way. Be sure to cap off the oil feed hose.