How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Marty Your Own Question
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53985
Experience:  Bosch Certified Master Tech. Over 35 years experience.
Type Your Mercedes Question Here...
Marty is online now
A new question is answered every 9 seconds

Amedee My name is ***** *****. I have a Mercedes E320 2004 -

Customer Question

HI Amedee My name is ***** *****.
JA: Thanks. Can you give me any more details about your issue?
Customer: I have a Mercedes E320 2004 - it has done 260 000kms. When I drive the car for over an hour the car starts jerking and loses power. When I pull over and stop for ten mins, then the car is able to be driven, but the jerking and loss of power comes back. The problem is not prevalent when only driving short distances.
JA: OK got it. Last thing — Mercedes Mechanics generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Customer: Do you have any idea what the problem might be?.
Submitted: 1 year ago.
Category: Mercedes
Expert:  Marty replied 1 year ago.

Hi, my name is***** problem that you are describing sounds most like loss of fuel pressure from the fuel pump. It sounds like the pump is overheating when driven for a long period of time and losing pressure. I would recommend that the fuel pump be tested for faults. If the check engine light is coming on you should have the fault codes checked to see if they point to a faulty sensor but this problem sounds more like loss of fuel pressure after driving awhile. I suspect that the fuel pump will need to be replaced.

Let me know if you have any questions. Please remember to rate my service in order for Just Answer to credit me for helping you.


Customer: replied 1 year ago.
Another service technician said it could be dirty transmission oil that needs to be replaced, or that the level of oil in the transmission is low - is that likely ?. Can it be a transmission problem or is it more likely to be fuel pressure. The problem only occurs on long distance journeys after two hours or so.
Expert:  Marty replied 1 year ago.

Hi, it is very unlikely that this is a transmission problem. The transmission on this model rarely leaks oil and if there was a transmission fault the transmission would go into limp home mode and would not change gears. This sounds more like loss of fuel pressure.

Let me know if you need anything else.