S60R misfire

[Nick0]

Hello all,
Recently been experiencing an intermittent misfire, drove 200 miles on Wednesday night and it became more prevalent. Called the Volvo Assist mobile mechanic out yesterday, he checked the coil packs visually, and took the camshaft position sensor out and cleaned it with carburettor cleaner, fired it up, plugged the computer in and it showed an engine misfire which had been cleared. I took it round the block and it did seem better. He went off to his next job, and of course later it bloody well happened again. I spoke to the nearest dealership (Rybrook Warrington, what a useless bunch of *******) who quoted me £50 for a new sensor.

So, question is, is this the most likely culprit - should i just buy it and replace it, or buy the coil packs too? Got the return 200 mile journey on bank holiday bank holiday monday, don't fancy a poxy breakdown with missus and 6 year old in the back. Car is MY2006 with 57k on the clock and been properly maintained.
Many thanks in advance,
Nick0

[Santa]

Hard to say, would get the codes read before investing in a sensor. If the codes point to the sensor then its worth replacing :)

[Nick0]

unfortunately i don't have the time to get it to a garage to get codes checked, we are meant to be going back 200 miles on bank holiday monday...

[stribo]

Find out which cylinder has the misfire, then swap coilpacks with a different cylinder, and see if the misfire moves with it.

[wallace570]

Find out which cylinder has the misfire, then swap coilpacks with a different cylinder, and see if the misfire moves with it.

or unplug then replug one at a time, you will know what one misfires when the tone doesn't change. when u put the foot down does it stutter then take off but with not full power?

[Dream3r]

On your car VIDA will register which cylinder is misfiring. I'd start there.

[stribo]

On your car VIDA will register which cylinder is misfiring. I'd start there.

My generic code reader gave me the code for which cylinder was misfiring, changed the coil pack, all was fine.

[Nick0]

Thanks all. Bought the poxy 50 quid sensor fitted it and it stuttered a few times on the 200 mile journey home tonight. Will it register anything in vida given that its an intermittent problem? Been suggested on another forum that plugs could be the culprit. Will check both the coil packs and plugs.

[LeeT5]

Why does everyone think that a misfire is always a coil?
It could likely be a lazy or faulty fuel injector or a spark plug.

How much more more money are you gonna throw at, replacing sensors that don't need replacing?

[Dancake]

It could be faulty coil, spark plug, ht leads if fitted, low compression, faulty injectors or injector wiring, unmetered air intake through a cracked pipe after the maf, timing issue, camshaft or crankshaft position sensors. Maybe even the coolant temperature sensor. Vida will tell all. Saying that, I spent the past two weeks trying to diagnose a misfire on a Seat Ibiza. Turned out to be an ECU issue.

[LeeT5]

It could be faulty coil, spark plug, ht leads if fitted, low compression, faulty injectors or injector wiring, unmetered air intake through a cracked pipe after the maf, timing issue, camshaft or crankshaft position sensors. Maybe even the coolant temperature sensor. Vida will tell all. Saying that, I spent the past two weeks trying to diagnose a misfire on a Seat Ibiza. Turned out to be an ECU issue.

Well said. (I couldn't be bothered to rattle them all off).

Nick, the first thing I'd do (other than VIDA diagnosis) is pull out and inspect your plugs....ALL of them!
Mine developed a random misfire before I fixed my cracked IC issue and it was found to be the plugs. Chucked a new set in and the misfire totally went and the car drove much smoother. If there's any hint of fouling or they just look tired and worn, replace them. Especially if they've done 20k +.