Spark plugs and ignition coils at the same time?
Thread Starter
Junior Member
Joined: Oct 2023
Posts: 22
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From: Lake Oswego, Oregon
'13 G550, '77 FJ40, '18 F350, '87 Westy, '87 Wolfsburg, '17 GLE350, '08 GL550
Spark plugs and ignition coils at the same time?
What's the consensus? Do you guys replace them at a certain mileage or wait till you get symptoms and confirmed by the OBDII? A couple weeks ago, i started the G550 (M273) and got the Check Engine light, with a rough, unbalanced feel in the motor. I quickly turned it off. I restarted and it was perfect. Never had it happen again. Is this an early sign of a coil going bad? My G has 118k miles.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
Out Of Control!!
Joined: Apr 2019
Posts: 12,014
Likes: 6,835
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
complete ignition set
What's the consensus? Do you guys replace them at a certain mileage or wait till you get symptoms and confirmed by the OBDII? A couple weeks ago, i started the G550 (M273) and got the Check Engine light, with a rough, unbalanced feel in the motor. I quickly turned it off. I restarted and it was perfect. Never had it happen again. Is this an early sign of a coil going bad? My G has 118k miles.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
Having unquestionable ignition is a good factor towards longevity. Keep your ignition parts all identical.
New coils mean you will hardly need to question ignition if/when misfires decide to show up.
## EQS - HK Tsim Sha Tsui
Last edited by CaliBenzDriver; Today at 07:30 AM.
Out Of Control!!
Joined: Sep 2018
Posts: 14,697
Likes: 4,591
From: unbegrenzt
2017 GLE350 4MATIC
What's the consensus? Do you guys replace them at a certain mileage or wait till you get symptoms and confirmed by the OBDII? A couple weeks ago, i started the G550 (M273) and got the Check Engine light, with a rough, unbalanced feel in the motor. I quickly turned it off. I restarted and it was perfect. Never had it happen again. Is this an early sign of a coil going bad? My G has 118k miles.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
I'm probably doing the plugs in the next day or two. Wondering if i should also do the coils. I'd still have to order the coils, so that would be done later.
I never wait for a code to replace coils.
I generally target 100k miles for coil replacement. There is nothing precisely scientific about this replacement interval. More often is more money spent than I think is necessary. Less often means the engine is running rougher than I know is possible.
