P0303 VOLVO - Cylinder 3 Misfire Detected once a week - why???

Question

Last week I spent over $900 in repairs on my 2007 Volvo V50 when the P0303 VOLVO - Cylinder 3 Misfire Detected occurred after a hard cold start and Check Engine light turned on and the situation could not be duplicated.  All of the ignition wires and spark plugs were replaced.  One week later, the same situation happened.  Again, not able to duplicate.  There are over 130,000 miles on the vehicle.  I am the second owner (for 1 year) and don't know the history of maintenance.  Before I start throwing more money at this I was wondering if anyone has any suggestions of possible quick, inexpensive checks for other possible causes.  I should have reached out to ya'll before I spend the $900.  Thanks in advance.

Answer 1

P0303 Misfire number 3 cylinder

What you have is a intermittent misfire condition, One suspected area that has to be ruled out is the canister purge valve it very possibly that it gets slightly stuck open and affect the air to fuel ratio when cold, Purge valve are notorious for causing problem

Comments

Thanks Reynaldo!  If it happens again (hopefully it won't), that will be the first thing I ask the mechanic to check and will report back.

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Volvo a tricky engine you need to understand the territory of the Volvo, To begin with you should not even have a cold hard start, But still be aware that Volvo gives false misfire codes on a cold start, that Volvo has produced a TSB on this where the ECM is updated for reporting false misfire codes TSB # 28-76