Misfire at low revs
#1
Misfire at low revs
Hi guys,
I have a S70 T5 1998. during the past couple of weeks misfiring has gotten progressively worst. Seems to be more noticeable as the engine heats up and at low revs - particularly when stationary at the lights!!. If I get up to 2k revs, misfiring is very much reduced. This leads me to think that it is not the coil or plug leads.
The car has been recently serviced and no obvious faults found. I have read that a problem for the 70 series was the spraying of a fine oil mist from a worn camshaft seal into the distributor which will give major misfiring.
Would anyone on the forum who reads this thread and be aware of this oil problem like to enlighten me as to the effect it has on the distributor. Also, perhaps there might be something else I could look at.
I don't have a code reader yet. Also, what does CEL mean, I see it mentioned regularly.
edit: One other observation. When idling, the engine has a soft thumping sound. My daughter has a S70 20v she doesn't have the thumping sound.
Thanks guys
bobbie
I have a S70 T5 1998. during the past couple of weeks misfiring has gotten progressively worst. Seems to be more noticeable as the engine heats up and at low revs - particularly when stationary at the lights!!. If I get up to 2k revs, misfiring is very much reduced. This leads me to think that it is not the coil or plug leads.
The car has been recently serviced and no obvious faults found. I have read that a problem for the 70 series was the spraying of a fine oil mist from a worn camshaft seal into the distributor which will give major misfiring.
Would anyone on the forum who reads this thread and be aware of this oil problem like to enlighten me as to the effect it has on the distributor. Also, perhaps there might be something else I could look at.
I don't have a code reader yet. Also, what does CEL mean, I see it mentioned regularly.
edit: One other observation. When idling, the engine has a soft thumping sound. My daughter has a S70 20v she doesn't have the thumping sound.
Thanks guys
bobbie
Last edited by bobbie; 02-06-2010 at 11:43 PM. Reason: additional info
#2
#3
#6
#7
Hi guys,
Update, the missing has been so bad that I bought a Haynes Workshop Manual, not wanting to go and spend another couple of hundred dollars to someone who should have probably seen the problem coming.
My original diagnosis it seems might be correct. The article I read on a common fault from a fine mist of oil into the distributor might be spot on. The inside of the distributor cap had a ring of black carbon deposit connecting the points where the rotor causes the spark to occur. I concluded that the rotor must have been "arcing" across the carbon trail as the car heated up.
It took a bit of time to clean off - used a cloth with white spirit and fine sandpaper. Got the "Sprint" back into the car. Boy is this car quick again!
Should now look at replacing the camshaft oil seal, as there is a small residue of oil behind the rotor cover.
Hope this helps someone else who might get a similar problem.
Regards
Update, the missing has been so bad that I bought a Haynes Workshop Manual, not wanting to go and spend another couple of hundred dollars to someone who should have probably seen the problem coming.
My original diagnosis it seems might be correct. The article I read on a common fault from a fine mist of oil into the distributor might be spot on. The inside of the distributor cap had a ring of black carbon deposit connecting the points where the rotor causes the spark to occur. I concluded that the rotor must have been "arcing" across the carbon trail as the car heated up.
It took a bit of time to clean off - used a cloth with white spirit and fine sandpaper. Got the "Sprint" back into the car. Boy is this car quick again!
Should now look at replacing the camshaft oil seal, as there is a small residue of oil behind the rotor cover.
Hope this helps someone else who might get a similar problem.
Regards
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