Hello All!

I have a 2001 S40 1.8T w/ 116k on the odometer. I've done a lot of work on it this year as it passed the 100K mark. Before 100K, I never had a single problem with it.

I am getting a P0304 code for a cylinder 4 misfire. I had misfires last year and I have since replaced the 2 coils, which solved the problem. Today, I switched the coils and the wires on all of the cylinders. The problem did not move with the plugs or wires. Normally, I would expect that misfires on 4 would appear on 1 and vice versa. I also switched the spark plugs around, and the problem did not move from the 4th cylinder. I still get the same code, and the car still stutters under heavy acceleration. I just threw in some Techron cleaner to see if that helps.

Any suggestions?

THANKS!

 

I had the same issue w/ my 2000. I replaced the plugs, coil packs but the code returned. I cleaned the MAS and the IAC and found that the intake line (under the IAC), off of the inter cooler, was cracked.

http://s40concepts.net/forum/index.p...b1bce0b4860f8f

5th picture, you can just see part of the intake line at the bottom (under the IAC).

The crack became obvious when I poked it and the line split in half.

It is a Volvo dealer line since it is formed and a different size on each end but my code went away.

 

Thank you. Good info. What the hose difficult to replace? I am afraid to touch it without having a spare handly. Could strand myself here.

 

The old hose was baked on but easily removed. The old hose has two crush clamps that have to be cut off. You will need to get two clamps for the new hose. The hose slides on easily, the only "problem" is aligning the bottom clamp so that you can get on it to tighten it.

It is almost easier to go ahead and clean the IAC at the same time since it is on top of the intake hose.

btw the links to cleaning the MAS and IAC is in the FAQ that Lyonsroar posted at the top.

 

Just wanted to provide an update. I eventually gave up and I called my mechanic to make an appointment. He told me that the S40 will sometimes throw out the same code over and over even though the problem has gone to a different cylinder. He was right. I replaces the plug wires and plugs and everything works fine. So much for my logical troubleshooting.

 

I am having a similar problem with my '02 S80. Code says cylinder 3 misfiring--gonna take it to a mechanic who works exclusively on Volvos/BMWs. Assuming it takes rrpcement of coils and plugs, any idea of a ball park cost?

Is it dangerous to drive short term--100 miles or so?

Thanks

 

You dont want to drive a car that has a flashing CEL. Normally the CEL will flash with a misfire. If its just the sparks not working thats not to difficult to change (on the S40 they are right on top under the plastic cover). Double Platinum NGKs run about 12 bucks each. Regular platinum plugs are around 4 bucks each. Genuine Volvo ignition coils are around 80 bucks each I think. So if you can swing it yourself you will save a ton of cash. I think I had mine done to clear a P0303 and it cost like 400 bucks. Never again.

 

Many thanks