stevedavies

Had a problem occur driving home from work today. Engine lost a lot of power, difficult to accelerate. At stop idle drops right down to 200rpm but recovers to 700rpm Engine seems stable at idle, but when I try to accelerate its very rough and lacks power. All internal gauges look good, water temp, oil pressure, batt voltage no change. Did intake refresh about 500 miles ago and everything has been fine since, has been a daily drive for a month now. Any ideas where to start looking??

stevedavies

Thought I would start with spark plugs. One plug ( 3rd from front of car, passenger side RHD) was covered in engine oil. All others looked good. Claened up oil and engine running good again. Is this a bad sign of impending doom ? No sign of water in oil or oil in water. Was surprised to see so much oil on the electrode ( I drove the car for 4 miles with misfire to get home). Would you expect this?

jeff spahn

Perhaps when you did the intake refresh you didn't replace the spark plug gaskets and that one is leaking?

stevedavies

Jeff, when i did the intake I also put new spark plugs in. Didnt disturb the cam covers. Maybe I need to run it some more and see it it occurs again. It just seemed wierd for the plug to oil up after 500 miles

jeff spahn

Steve. Hmmm. Since you didn't disturb the cam covers I guess it throws that idea out. Unless it just happens to be your time that they decided to leak. In doing my refresh I noticed the DS cam cover was off in the last 5 years or so my records say. PS was original. PS were rock hard and were leaking at gaskets. DS were supple and weren't. Replacing all 8 of them.

stevedavies

Jeff, I am going to try running it for a while but I can see me going back in soon!!

James Bailey

Perhaps do a compression check to see how the rings are doing. One cylinder down is ONLY a small loss of power. On the other hand running on four is a major drop. If your car is cat equipped and has the head/exhaust temp sensors that is a possible fault.

Gregg K

I once had moisture in my distributor caps, and the car behaved this way. It's probably not the problem, but I thought I'd throw that out there.

That wouldn't explain the oil, per se.

stevedavies

Jeff, I have just realised what you meant in your post. I initially thought you meant the metal sealing ring on the spark plug itself. I just checked the parts catalogue. It looks like there are sealing rings associated with each of the spark plugs ( 928 104 443 08). I guess this is what you meant. Would these leaking allow engine oil to get to the electrode? Ther was quite a bit of oil when I took it out. Is it simply a question of removing the cam cover and replacing seals?? I have never removed cam covers so not sure what is involved ( as opposed to intake where I spent most of last sumer).
James, when I cleaned plug engine seemed to run ok again, so hopefully its nothing more serious. I will do compression check though, wouldnt harm to get a reading of all cylinders

James Bailey

Yes Gregg that would be four down, 1/2 the ignition. I think that is more likely the case.

Speedtoys

When was the last time ALL of the ignition was replaced as a set?

Coils, caps, rotors, wires..

stevedavies

I havent done anything to ignition system ( apart from new plugs) in 2 years of ownership.... maybe its time!!

Hilton

Symptoms sound like its running on 4 cylinders.

Unplug the leads from the coils to the distributor caps. Check both ends of each for corrosion, and spray with contact cleaner or similar if there's some. Then re-plug. Don't drive the car around like this - running on 4 can damage the crank.

Do you have a light on on the clear relay by the ECU's? red or green LED.

karl ruiter

The head cover gaskets have several parts: the big part goes around the outside of the head cover, but there are also 4 O shaped seals that go around each spark plug hole. When they get old they leak and can fill the plug well with oil. The plugs don't much like being in an oil bath and can start to misfire. You can do a temporary fix by just pulling the plugs out, cleaning them, and putting them back. This lets the oil drain down into the cylinders. Your neighbors will hate you because when you fire it back up you will have to burn off that oil and it makes a huge amount of smoke, but I have had this fix power loss problems sometimes.

stevedavies

Karl, your thinking is the same as mine. When I took plug out there was a lot of engine oil on electrode. If there was a bath of oil surrounding the plug, when I took it out it would have flowed down to the electrode. When I cleaned it engine runs good. I am going to run it for a while to see if the problem re occurs, Am surprised the oil got past the threads down to the electrode to cause the misfire though?