Dropped two cylinders... bad coils.
Thread Starter
Super Member
Joined: Dec 2011
Posts: 549
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From: Oregon
'97 c36
Dropped two cylinders... bad coils.
I had been noticing the car running a little funny. Not really anything you could point at but enough you could tell something was off. Mileage had decreased but power was still there. So was putting off looking into it till I had some free time.
Well heading towards the highway after work couple months ago and it felt down on power, not terrible but a little sluggish. I was giving it throttle to catch traffic on highway 217 and right after it downshifted It lost a lot of power and the check engine light came on.
No bad noises and all gauges and warning lights looked ok. Other than the check engine light. So I decided to keep doing till I could exit off and take a look. Found a furniture store with tons of lights sure enough it was down a couple of cylinders. Pulled the injector connectors till I found which cylinders it was and they matched a coil. Since I was and hour from the house with no spare parts. I just left the injector plugs off those cylinders to keep gas from washing the rings and limped it back to the house. (It was kinda interesting, with those two holes turned off and just pumping air. The car wouldn't/couldn't build temperature. )
Anyways got it home and the next day took a look at it. Sure enough not one but two coils had cracked and was leaking spark. Replaced all the coils with the exposed metal core style and back on the road. They are cheap enough I bought an extra as a spare to carry with me in the car. Anyways... next time your due for a spark plug service might take a look at the coils at least on the 104's dunno if the v8's use this same coil or not.
B
Well heading towards the highway after work couple months ago and it felt down on power, not terrible but a little sluggish. I was giving it throttle to catch traffic on highway 217 and right after it downshifted It lost a lot of power and the check engine light came on.
No bad noises and all gauges and warning lights looked ok. Other than the check engine light. So I decided to keep doing till I could exit off and take a look. Found a furniture store with tons of lights sure enough it was down a couple of cylinders. Pulled the injector connectors till I found which cylinders it was and they matched a coil. Since I was and hour from the house with no spare parts. I just left the injector plugs off those cylinders to keep gas from washing the rings and limped it back to the house. (It was kinda interesting, with those two holes turned off and just pumping air. The car wouldn't/couldn't build temperature. )
Anyways got it home and the next day took a look at it. Sure enough not one but two coils had cracked and was leaking spark. Replaced all the coils with the exposed metal core style and back on the road. They are cheap enough I bought an extra as a spare to carry with me in the car. Anyways... next time your due for a spark plug service might take a look at the coils at least on the 104's dunno if the v8's use this same coil or not.
B
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Good trouble shooting and fix 
No the 43's use a completely different coil with 2 leads 
No the 43's use a completely different coil with 2 leads
Thread Starter
Super Member
Joined: Dec 2011
Posts: 549
Likes: 0
From: Oregon
'97 c36
Thanks, Figured I'd share. I guess it happens from time to time. I was reading some where that the plastic would crack from heat fatigue since the coils are under the plastic cover on the valve cover.
