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Kurt Kennedy
Kurt Kennedy, ASE master with L1
Category: Mercedes
Satisfied Customers: 93
Experience:  Shop foreman at Auto-Lab of Texas
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I have a 2003sl55amg. The issue is that the the engine chugs

Customer Question

Hi, I have a 2003sl55amg. The issue is that the the engine chugs when driving and when the car is in neutral the revs shoot right up. Only happened today
JA: How many miles are on the car? What size is the engine?
Customer: 109000 and a 5.4
JA: Tell me a bit more about what's going on so he can help you best.
Customer: Only had it 2 months
JA: Are you hoping to fix this yourself?
Customer: Not if its something really technical. I am practical but don't have mechanical experience. I just want to know if its something common
JA: Is there anything else the Mercedes Mechanic should be aware of about your Mercedes?
Customer: The car has lost power 3times since I got it. I took it to a mercy mechanic who says it might be the throttle body actuator and supercharger pump... potentially overheating. I wondered if what I mentioned before is a symptom of this fault?
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Mercedes Mechanic about your situation and then connect you two.
Submitted: 9 months ago.
Category: Mercedes
Expert:  Kurt Kennedy replied 9 months ago.

Sorry you are having issues with the AMG.
You said this only happened one time? Did you happen to have a check engine light set, or flash during this event? Once you cycled the key did the prob go away?

Thanks!

Customer: replied 9 months ago.
The engine check light came on after the engine lost power the first time and stayed on until I took it to the garage that week , and they told me about the throttle body actuator.. today , for the first time the car has been chugging during a long drive, even on cruise control. And when impute the car in neutral, the revs shoot up. This hasnt happened before. As I say I am hoping these are all linked with what the mechanic told me. Its booked on again later this week.
Customer: replied 9 months ago.
Hey, Kurt,Any ideas?
Expert:  Kurt Kennedy replied 9 months ago.

Awesome, thanks for answering my questions. I know they seem kinda random, but they help me and give me a direction to go. This 100% sounds like a throttle body issue. These cars tend to act up exactly as you described when the throttle body gets hot and starts to short out internally. The computer sees a signal that is "implausible" and doesn't know whats going and gives you the exact situation you described.

I really hope this help (Sorry to the late reply) Please let me know if you have anymore questions and please do not forget to rate my service since that is the only way i get credit for my answer.

Thank you!!

Customer: replied 9 months ago.
great, many thanks
Expert:  Kurt Kennedy replied 9 months ago.
Anytime! Feel free to ask anymore questions and please don't forget to rate my service if you have not already done so!
Have a good one!