Hi all.

My friend has an 02 XC70 with roughly 100k miles. As we were about to start the long drive home last weekend the engine started to stumble and the check engine light came on and then began flashing.

All fluids and belts look good (though it is overdue for a timing belt) after topping off the oil which was pretty low (though I think unrelated and was topped off). Got it to an Advanced Auto Parts and had them run the OBD-II scan and came up with a cylinder 3 misfire. Added some seafoam to try and clean things up in case it was just some fouling and limped it home. It isn't getting better, but it isn't getting worse.

My initial reaction / cheapest possible fix is new plugs (she's had the car about a year and doesn't know most of the service history). I'm about to swap them out and will report back, but was wondering if there are other typical issues that I can check if it's still misfiring after changing the plugs?

Thanks!

 

So I pulled the plugs. Cylinder 3 was definitely fouled, though even with the new plug it stumbled. Pulled the #3 plug again and it was moist with fuel, so it looks like it's not getting a spark.

My guess is a bad coil pack? Would anyone agree? Recommendations for replacement parts, or parts to avoid? How likely are the others to start failing as well?

 

when was a complete tune up done. doing a tune up helps prevent problems like that.new plug wires, distributor cap and rotor,new spark plugs. if the engine does not get enough volts from the wires it can cause the plugs to miss function and not give enough spark. get oem parts from FCPeuro.they have reasonable prices on parts.

 

Not sure on the last tune up. It was purchased used a year ago, not much service history. Sounds like the brakes were done but I'm not sure what if any engine work other than oil changes has been done since buying it. As I said I just swapped the plugs, and will be changing out this ignition coil pack. The air filter looked reasonably clean. I don't think with coil packs it still uses a cap and rotor and the "plug wires" are more of a wiring harness, so I don't think they follow the same service interval as traditional plug wires.

 

change the ignition coil pack and lets see how it runs.get back to me with updates or you can private message me

 

Swapped out the coil pack. Seems to be running like normal again.

 

good to hear you are back on the road again.

 

I had a similar problem and suspected the coil pack. What I did was swap that coil pack out with a different cylinder and drove the car until the Check Engine light came on again. When the new reading showed the same swap I had made I knew it was the coil.

 

sooo one of my friends owns a 2002 volvo v70 xc turbocharged and she put low grade gas in the car close to the end of the tank the engine starts shuttering and the check engine light came on and started flashing the misfire happend at 1,850 RPM under 16.9% load i have a code reader so i ran the diagnostic i got P301 cylinder 1 misfire and Po234, Turbo over-boost, and now the shuttering is the motor toast???? someone help!!!!!
seems alot like pre detonation but i didn't hear any metallic sounds

 

I doubt it. I would trouble shoot the misfire first, then other issues.