Rough idle when cold then smooth when warm
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2010 E550
Rough idle when cold then smooth when warm
Any one on here had an issues with there 5.5l engine having a rough idle when it’s cold?
my problem- starts up good and strong but when idle drops to 600-650 it is very shaky and misfiring. If you give it gas it is smooth and when driving with it cold it’s still smooth and no miss. Once the temp gets up past 80 Celsius the the idle is smooth with no issues. Car has plenty of power And runs completely normal once warmed.
Car is a 2010 E550 with 170k miles on it
check engine light on for p0420(catalytic converters) and p0307(cyl 7 misfire)
i have put new Bosch oem plus in it and swapped cyl 7 coil to no difference. Cleared codes and still comes back to cylinder 7.
Is there any common issues with this or has anyone else had this problem?
my problem- starts up good and strong but when idle drops to 600-650 it is very shaky and misfiring. If you give it gas it is smooth and when driving with it cold it’s still smooth and no miss. Once the temp gets up past 80 Celsius the the idle is smooth with no issues. Car has plenty of power And runs completely normal once warmed.
Car is a 2010 E550 with 170k miles on it
check engine light on for p0420(catalytic converters) and p0307(cyl 7 misfire)
i have put new Bosch oem plus in it and swapped cyl 7 coil to no difference. Cleared codes and still comes back to cylinder 7.
Is there any common issues with this or has anyone else had this problem?
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2019 G70 6MT & 2022 Ford Maverick XL
So you've chased the misfire a bit - what have you done about the P0420? Also seems you are using a generic scanner, try hooking it up to a scanner capable of Mercedes specific diagnostics. They don't cost a ton of money.
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Any one on here had an issues with there 5.5l engine having a rough idle when it’s cold?
my problem- starts up good and strong but when idle drops to 600-650 it is very shaky and misfiring. If you give it gas it is smooth and when driving with it cold it’s still smooth and no miss. Once the temp gets up past 80 Celsius the the idle is smooth with no issues. Car has plenty of power And runs completely normal once warmed.
Car is a 2010 E550 with 170k miles on it
check engine light on for p0420(catalytic converters) and p0307(cyl 7 misfire)
i have put new Bosch oem plus in it and swapped cyl 7 coil to no difference. Cleared codes and still comes back to cylinder 7.
Is there any common issues with this or has anyone else had this problem?
my problem- starts up good and strong but when idle drops to 600-650 it is very shaky and misfiring. If you give it gas it is smooth and when driving with it cold it’s still smooth and no miss. Once the temp gets up past 80 Celsius the the idle is smooth with no issues. Car has plenty of power And runs completely normal once warmed.
Car is a 2010 E550 with 170k miles on it
check engine light on for p0420(catalytic converters) and p0307(cyl 7 misfire)
i have put new Bosch oem plus in it and swapped cyl 7 coil to no difference. Cleared codes and still comes back to cylinder 7.
Is there any common issues with this or has anyone else had this problem?
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2011 E-350 4Matic Sport
Don't overlook the possibility of unmetered air (vacuum leak) especially at intake gaskets. Leaky gasket can close up as surfaces warm and expand.
Rather than a long post, this video from SMA explains the basic diagnosis - applies to many engines. You can also use generic OBD scantool that shows live data to look at open/closed loop status, O2 and fuel trim data.
Rather than a long post, this video from SMA explains the basic diagnosis - applies to many engines. You can also use generic OBD scantool that shows live data to look at open/closed loop status, O2 and fuel trim data.
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From: Pepper Pike Ohio
24 GLS580 '23 E450 4matic 12 E350 4Matic
I think Arrie's got this one with the clogged injector, not to discount that Mud could be right too! 
I would suggest some Techron complete fuel injection cleaner, like two bottles in 12 gallons and some freeway on-ramp launches.
I would suggest some Techron complete fuel injection cleaner, like two bottles in 12 gallons and some freeway on-ramp launches.
Last edited by pierrejoliat; Jan 10, 2021 at 12:34 PM.
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From: 122W, 37N
2016 E350 4Matic wagon, 2019 Ford Expedition, 2019 Chevy Bolt EV
my injector cleaning regimen involved waiting til the tank was almost empty, put in a whole bottle of whatever, add no more than 6-8 gallons of gas, get out on an open rural highway, and downshift a couple gears so you keep your RPM high. like 4000-5000 rpm, and drive that tank close to empty.... then fill it up, drive /that/ close to empty and plan on doing an oil change fairly soon.
but that was back in the days of CIS systems (Bosch K/KE Jetronics).
but that was back in the days of CIS systems (Bosch K/KE Jetronics).
