2002 S40 1.9 Turbo 68K, recently started having rough idle, check engine ligth came on, code at parts store idicated cylinder 3 misfire.
Replaced spark plugs, one was noticeably more dirty than others(the third from the left looking into engine), idle remained rough no improvement. Examined ignition coils and all plug shaft boots, no hairline cracks of any kind.
Replaced air filter and cleaned MAF sensor, no improvement.
Replaced fuel filter, no improvement.
Put Seafoam in a vacuum hose, oil crankcase and fuel tank, idle improved no check engine light but acceleration sluggish. Changed oil after 50 miles with seafoam, idle became rough check eng light back on. Put more seafoam in oil crankcase, idle improved but slight hesitation still detectable and acceleration still sluggish. What is next area to examine/replace to resolve problem? Also, there was no smoke when Seafoam was used, used it the same way as shown at this site http://www.channels.com/episodes/show/9862...aming-The-Volvo
Thanks!

 

sounds like your coil pack is/has gone bad!!! I had this problem with my old volvo 960 and my co-worker had a volvo c70 and his car starting missing firing/running rough and I told him I thought he had a bad coil pack....of course he did not listen and spent several hundred dollars buying this, buying that...I suggested he take the car to the local meineke shop which will diagnoise the problem for free, they told him he had 3 coil pack that went bad and wanted to charge him $1,200 to replace the coil packs I told him to order the coil packs from our local autozone for around $50-$60 a piece or go here: http://www.europartsdirect.com the price will vary depending on what make/model car you have....I had my co-worker change the remaining 2 as well since he would have replaced 3 and could potentially have an issue with the other 2 down the road total cost for all 5 coil packs $280.00 labor $0....this is an easy fix and a mechanic is not needed! good luck and post your results please!!! Carlton

 

Took the car to Meineke, they found a broken wire in the coil ignition package but coil itself fine. They fixed the wire and also told me I had the wrong brand of spark plugs. Volvos need plugs designed for their euro engines and put in NKGs to replace the autolites that the parts supply told me would work. All codes are clear, ignition coils clean and firing exactly as they should, fuel trim is good, plugs gabbed properly, idle is fine however there is still hesitation and some sluggishness in acceleration. Without a code Meineke has no idea and would need to become very invasive and replace all kinds of things to try to fix it. Any thoughts? Fairly recently put in 44k fuel injector cleaner and Seafoam just the other day. Could seafoam in oil or fuel still be causing acceleration problem?

 

Fairly recently put in 44k fuel injector cleaner and Seafoam just the other day. Could seafoam in oil or fuel still be causing acceleration problem?[/quote]


it is possible, I WOULD NOT have put seafoam in the engine...before doing anything like that it is always best to post your issue...I am not saying that you will have any further issues, once the seafoam is out of your engine all should be fine...me on the other hand use bosch platinum plugs on my volvo's always have always will...better plug(IMO) drive your car for a couple of days and see if it is still sluggish... you could still be having issue with your fuel injectors or something still tied into the coil pack or the harness for the coilpack....let me know!!! BTW....how much did meineke charge you for all of this???

 

Meineke charged $100. I will let you know if things have improved for better or worse after a couple days. Thank you for your assistance.

 

cylinder specific codes are almost always a bad coil. check the plugs. if one plug is more fouled than the others, it's a bad coil on that cylinder. if you pull a multiple cylinder misfire, which is basically 2 or more cylinders misfiring, then you can start suspecting a common cause. hold off on the seafoam next time till you have exhausted all other options. coils are in a high heat environment, and over time they will break down. do not be surprised is you have to replace another one sooner than later.

 

by the by. there are only 2 coil packs on the 1.9T. 1 on cyl 3 and 1 on cyl 4. cyl's 1 & 2 use traditional coil wires piggybacked off cyl's 3 & 4. don't know what "wire" was replaced, but if you are staring down at your engine, then the 3rd from the left is cyl 3. also try swapping the injector for that cyl with one from another cyl. if no change, then the only thing left is a compression test. start with the coil. for the record, autolites suck for european engines. i use NGK.

 

really not that bad since NGK plugs are expensive to buy at your local autozone...advance auto or parts store for that matter....next time you change your plugs to bosch platinum, I think you will like these plugs better than the NGK....so labor was around $50 bucks not bad I thought you would have paid more so that was pretty cheap! Again good luck and keep us informed of any further issue you might be having!

 

Back again. A couple weeks after light was deemed off as previous posts indicate, despite mild, intermittent hesitation at idle continuing, the light is back on same code. We replaced the ignition coil itself and light was off for a day but now back on. We are convinced at this point it must be the wires that have a poor connection that only goes from alright to bad which trips the car computer and the light. What wire set or number should I be looking for? All I am finding is kits that include the coils or generic wires that do not seem appropriate. Thank you for you help. Volvo S40 2002.

 

You guys are going to a chain muffler shop for diagnostic work on your volvo!!??? I wouldn't let them touch any of my vehicles!!

Like olvoguy said, it's probably the coil but you should ck the compression just to rule that out; did your buds at meineke do that?

 

if you read my post.....I said take it to them to see if it was the coil pack, they do not charge for the diagnose of the car and why pay the volvo dealer to tell you what is wrong with the car when you can have it done for FREE????????? I did not say have them work on the car, once you know what the problem is you can the do the work yourself if you are mechanically inclined!!!