C70 Misfire

Herestandsaman · Sep 15th, 2017, 12:08

During my working day yesterday my C70 developed a Misfire.
The car lost power & struggled to maintain speed.
Vida showed ECM-3503 & ECM-3543, misfire no4 cylinder.
Also code p0301 showed on my scan gauge
I erased the codes, replaced all spark plugs & swapped no4 coil pack
I also did a full compression test, all was good showing 130+-, so that was a relief.
I took the car for a run, still have misfire & code returned !
Any help please ?

DunkinBiskits · Sep 15th, 2017, 17:14

swap cyl 4s coil with another cylinder. see if the fault swaps with it to the new cylinder. if so you've got a dud coilpack. if the fault is still cyl 4 then likely to be the spark plug itself

p0301 though is cyl 1 misfire, not cyl 4 (p0304)...... maybe you had 2 dead coilpacks

Herestandsaman · Sep 15th, 2017, 20:18

Hi thanks, I will try that.
I moved coil 4 to 1, as cylinder 4 showed as original failing on Vida
Will move 1&4 to 3&5 to see if codes move.
Any chance injector may have failed ?

Luxobarge · Sep 16th, 2017, 09:26

There's always a chance than an injector has failed, but statistically it's a very small chance - far more likely to be a coil pack, it's a common fault.

Don't run it for long with a misfire or you'll lunch your catalytic converter.

Herestandsaman · Sep 16th, 2017, 10:21

Success 😩 I think, switched coil pack & fault code moved to new position, so sure it is coil pack.
So, car has done 113k, do I replace all ?
Also, am I best buying genuine ?

DunkinBiskits · Sep 16th, 2017, 14:04

just find an uncracked OE used one. theres a few breaking ads on here, I'm sure someone will have something compatible for you.

new is always the best answer though if youre feeling flush

Sep 15th, 2017, 12:08	#1
Herestandsaman Member Last Online: Jan 1st, 2023 09:23 Join Date: Nov 2000 Location: sheffield	C70 Misfire During my working day yesterday my C70 developed a Misfire. The car lost power & struggled to maintain speed. Vida showed ECM-3503 & ECM-3543, misfire no4 cylinder. Also code p0301 showed on my scan gauge I erased the codes, replaced all spark plugs & swapped no4 coil pack I also did a full compression test, all was good showing 130+-, so that was a relief. I took the car for a run, still have misfire & code returned ! Any help please ?

Sep 15th, 2017, 17:14	#2
DunkinBiskits Master Member Last Online: Jan 1st, 2024 13:30 Join Date: Nov 2016 Location: Merseyside	swap cyl 4s coil with another cylinder. see if the fault swaps with it to the new cylinder. if so you've got a dud coilpack. if the fault is still cyl 4 then likely to be the spark plug itself p0301 though is cyl 1 misfire, not cyl 4 (p0304)...... maybe you had 2 dead coilpacks __________________ https://www.facebook.com/VolvoComposites/ Horsepower is how fast you hit the wall Torque is how far you take the wall with you Last edited by DunkinBiskits; Sep 15th, 2017 at 17:17.

Sep 16th, 2017, 09:26	#4
Luxobarge Premier Member Last Online: Today 13:19 Join Date: Jan 2011 Location: Horne (Nr. Horley)	There's always a chance than an injector has failed, but statistically it's a very small chance - far more likely to be a coil pack, it's a common fault. Don't run it for long with a misfire or you'll lunch your catalytic converter. __________________ Some people are like Slinkies, they serve no useful purpose but they still bring a smile to your face when you push them downstairs.

Sep 16th, 2017, 14:04	#6
DunkinBiskits Master Member Last Online: Jan 1st, 2024 13:30 Join Date: Nov 2016 Location: Merseyside	just find an uncracked OE used one. theres a few breaking ads on here, I'm sure someone will have something compatible for you. new is always the best answer though if youre feeling flush __________________ https://www.facebook.com/VolvoComposites/ Horsepower is how fast you hit the wall Torque is how far you take the wall with you

Sep 15th, 2017, 20:18	#3
Herestandsaman Member Last Online: Jan 1st, 2023 09:23 Join Date: Nov 2000 Location: sheffield	Hi thanks, I will try that. I moved coil 4 to 1, as cylinder 4 showed as original failing on Vida Will move 1&4 to 3&5 to see if codes move. Any chance injector may have failed ?

Sep 16th, 2017, 10:21	#5
Herestandsaman Member Last Online: Jan 1st, 2023 09:23 Join Date: Nov 2000 Location: sheffield	Success 😩 I think, switched coil pack & fault code moved to new position, so sure it is coil pack. So, car has done 113k, do I replace all ? Also, am I best buying genuine ?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)