GLK 250 - Limiting Revs at highway speeds won't accelerate
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GLK 250 Bluetec - 2015
GLK 250 - Limiting Revs at highway speeds won't accelerate
My Diesel GLK 250 won't rev over 2500/3000 RPM when I'm on the highway, even if I have my foot all the way down on the gas. It's limiting my revs and I can barely accelerate. I have no check engine light either so no codes to read.
When I turn the car off for and start it again its fine for a bit then after 15-20 mins of cruising at 100-120 km/h in 6th/7th gear it happens again it also disables the "manual" mode, not letting me use the paddle shifters, will only go in Eco or Sport. I feel as though I can hear an air leak or something as I accelerate before it goes into this "limp" mode. Any ideas for diagnosis?
Thank you
When I turn the car off for and start it again its fine for a bit then after 15-20 mins of cruising at 100-120 km/h in 6th/7th gear it happens again it also disables the "manual" mode, not letting me use the paddle shifters, will only go in Eco or Sport. I feel as though I can hear an air leak or something as I accelerate before it goes into this "limp" mode. Any ideas for diagnosis?
Thank you
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Joined: Nov 2023
Posts: 93
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From: St Stephen NB
GLK350 ML55 Ducati Porsche
Something similar happened on my ML55. Mine went into safety mode. Would not go over 30 mph. Took it into shop and they said it was due for transmission maintenance. Solenoids were replaced and drive fine afterwards. Good luck.
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Joined: Jul 2012
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From: WI
GLK 250
You are experiencing "limp home" mode, a safety setting that will allow you to at least get it home (or to a shop) rather than be stuck on the side of the road.
The sound of rushing air sounds like a boost leak. If the ECU determines there is one, it will put you in limp mode until it's fixed; restarting it won't solve the issue as boost is usually requested right away as you get going.
Most likely it's the S hose on the driver's side going from the intercooler to the intake piping. It is curious that you don't have a CEL on, which makes me think you might not be running stock software but I'll leave that alone for now.
Best bet: go to Auto Zone and have them check for codes with their scan tool. I bet you'll come up with an underboost code. If so, that hose is the most likely culprit. It'll be about $120 to purchase and about 20min of your time to replace if you're a little bit handy.
The sound of rushing air sounds like a boost leak. If the ECU determines there is one, it will put you in limp mode until it's fixed; restarting it won't solve the issue as boost is usually requested right away as you get going.
Most likely it's the S hose on the driver's side going from the intercooler to the intake piping. It is curious that you don't have a CEL on, which makes me think you might not be running stock software but I'll leave that alone for now.
Best bet: go to Auto Zone and have them check for codes with their scan tool. I bet you'll come up with an underboost code. If so, that hose is the most likely culprit. It'll be about $120 to purchase and about 20min of your time to replace if you're a little bit handy.
