2003 S60 multiple cylinder misfire - limp mode

quahog pearl · Post by **quahog pearl** » 20 Nov 2013, 10:42

This problem popped up suddenly right after I went through a big puddle Monday morning. Could be a coincidence, not sure. Vida gives me ECM? 3502 and 3503 multiple cylinder misfire messages. Last night I pulled the coils and plugs(NGK) and inspected carefully. You really couldn't notice any difference between them. They had a slightly wet with gas look to them, as if the mixture is off a bit. I cleaned the inside of the ETM which had an oily film on it. I also cleaned the mass flow sensor, but it really didn't need it.

Before I pulled the plugs, it was running as if it was completely missing on 1 cylinder. I plan on giving it a compression test tonight, but what has me stumped is why all the plugs look the same. Usually, 1 bad plug stands out, this is different. I'm thinking maybe if the fuel pressure is insufficient it might be running lean, but then I should have seen a lean bank code or something like that. Any ideas? Thanks, Pete

quahog pearl · Post by **quahog pearl** » 24 Nov 2013, 10:48

Plugs had 1.05 to 1.2mm gaps, so I regapped and reinstalled to 30 Nm. Ran better, but not nearly good enough. This time however, Vida identified cylinder 5 misfire in addition to multiple cylinder misfires.

I bought a new Bosch coil and Volvo plugs. That appears to be it, runs very nicely now. Thanks!