I have a 2001 Volvo s40 that runs great in till given significant gas. When you need it to move it hesitates and surges and has a hard time going past 4K rpm when giving a good amount of gas. The plugs wires have been checked out and passed the test but the plugs were getting old and they were replaced. #3 plug was filled with oil, I am not sure where that came from either the person who changed the oil missed a lot of oil or it is leaking out of the breather or pcv that is right next to it, does this happen a lot? I replaced all of this and it did not help. I read that these coils go out a lot but I don’t know how much of a symptom this is giving for a bad coil. Whenever it misses it flashes a code and so far I have been unable to get it to a shop to check out the code for lack of money and was wondering if any of you had a clue where to go before I take it to a local shop. Is there anyway any parts from the turbo could be causing this to happen at higher RPMs to cause a code and these effects.


Every bit of information is appreciated,
Thanks again

 

If the check engine light flashes while it is missing that means the engine is missfiring.I would remove and look at the coils.If they have any cracks in the plastic at all replace them.The problem you are having sounds like the typical bad coil problem.Since you replaced the plugs already and that didn't help.

 

Looked at the coil in #3 and there was a slight crack and in the boot you could tell that there was spark traveling threw. Sounds good to me!

However I believe the problem that initiated this was the oil that fell down the spark plug hole breaking down the plastic and making a good conductor. How did the oil get there? The design of the top of the engine looks very good and I cannot really tell where it could be coming from besides a few places. The first place is the breather or pcv that comes out from the middle in-between the spark plugs; it seems very unlikely and seems to be in good condition. The second is maybe the hex head bolts that it might be coming threw the threads but I don’t think it’s likely. Thirdly and most likely is that the oil fill cap is leaking down in to the top of the engine and shows signs of it or that someone did a horrible job changing the oil, I sprayed down the top of the engine and cleaned the cap because seems pretty dirty and might not be making a good seal so hopefully it will show me something. Do any of these happen a lot?


Thanks Tech for your helpfull information.

 

If there was oil in there most likely spillage from oil change.But those coils crack alot due to the high heat in the engine.Since the coils are plastic it is only a matter of time till they crack.

 

I really appreciate it. That was the problem and is running great! Actually found out both went bad! Pretty amazing how they are bad already.

Well thanks again saved me a lot of trouble!

 

It is kinda hard to believe.But remember they are in the center of all the engine heat from the engine.And thay are also made of plastic.