Occasional 4K RPM rev on start up
09-11-2019, 07:20 PM
#1
Junior Member
Thread Starter
Occasional 4K RPM rev on start up
Mysteriously, my 2019 wagon will occasionally rev to 4K on cold start up. It's just like you were fully stepping on the accelerator. Goes right back to normal revs afterwards and never does it if the engine is already warm. No set pattern to it but it just started doing this in the last couple weeks. Has only 1700 miles. Can't find any info on what could cause this. Going to have the dealer take a look but speaking with them, they're not sure what it could be. Very strange.
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Blackbear99 (12-04-2019)
09-11-2019, 09:08 PM
#2
Super Member
Mysteriously, my 2019 wagon will occasionally rev to 4K on cold start up. It's just like you were fully stepping on the accelerator. Goes right back to normal revs afterwards and never does it if the engine is already warm. No set pattern to it but it just started doing this in the last couple weeks. Has only 1700 miles. Can't find any info on what could cause this. Going to have the dealer take a look but speaking with them, they're not sure what it could be. Very strange.
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Foggy916 (09-12-2019)
09-11-2019, 09:54 PM
#3
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2023 AMG EQE 53
Get your phone ready and then start the car taking a video showing the tach, I'd keep doing this every time until I caught it doing it, then you have something to show the dealer and proof.
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Foggy916 (09-12-2019)
09-12-2019, 10:51 AM
#5
Junior Member
Thread Starter
Also, not sure if related or not but I've had three check engine lights since taking Euro Delivery this summer. One in Slovenia with just couple hundred miles (dealer in Slovenia couldn't figure out and simply reset computer). Second a week later coming back thru German before dropping off (AMG factory looked at it and said it was small debris in fuel injector which they fixed while we took the AMG factory tour...I think that is what they said but could have been lost in translation). Third about a month ago and local Texas dealer fix it (said it was an fuel evaporation line leak). No check engine lights since. However, I do notice a rough start sometimes and my guess is it has something to do with this high rev start up issue.....car seems to want to overcompensate for the rough start.
If this continues, I'm going to have to seriously take a look at state lemon laws. Can you imagine if this occurs while auto start/stop feature is on and it starts back up with high revs at a stop light while it's still in gear.....hoping that won't happen since the engine will likely already be warmed up. Plus I'm pretty sure that having a cold engine rev to over 4K RPM on cold start up is not good for the internals.
If this continues, I'm going to have to seriously take a look at state lemon laws. Can you imagine if this occurs while auto start/stop feature is on and it starts back up with high revs at a stop light while it's still in gear.....hoping that won't happen since the engine will likely already be warmed up. Plus I'm pretty sure that having a cold engine rev to over 4K RPM on cold start up is not good for the internals.
09-12-2019, 12:38 PM
#6
Super Member
It's happened once in the year and a half I've had my '18, probably 3 months into ownership, nothing since. Seems to happen more often for some people. My armchair assumption is bad gas, but only bad enough to trigger at startup, engine revs to compensate for what it perceives as knocking, then returns to normal operation.
