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

 

Hi guys,
Pretty warm here at the moment. I have just noticed an extra problem with the misfiring. When idling with the Air-Con, the misfiring is much worse.

I have worked out what CEL is! Check Engine Light!

Regards

 

Yes, it's a check engine light.It is telling you that you have a problem in your engine and it has a code for each problem. You have to get that code with a scanner and it will tell you what the problem is, well..most of the times.

 

Hi there,
thanks for the reply. the CEL comment was by the way. I don't have any CEL's showing when the engine is misfiring!

regards

 

Have you done a stage 0 yet (full tune up w/plug wires, cap, rotor, etc.)?

What was done when you had it "serviced"?

 

Hi,
It had a major service. "Everything" at 140000 km's. I have ordered a scan tool, which I should get by Friday. Will post the results as soon as I connect and read what the codes might be.

Thanks for the reply

 

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