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 Matt Your Own Question
Matt
Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22239
Experience:  BEng hons Mech engineering, in auto industry 22 years
12772297
Type Your Mercedes Question Here...
Matt is online now

I have a 2003 mercedes 220 cdi automatic and it won't go above

Resolved Question:

I have a 2003 mercedes 220 cdi automatic and it won't go above 3000 rpm
Submitted: 1 year ago.
Category: Mercedes
Expert:  Matt replied 1 year ago.
HelloThis could be a lack of fuel pressure from the electrical pump at the tank.If the connections to this are corroded or damaged then the pump could stop atany time or could not be running at full speed. Check that its relay switchesin and out and the relay contacts are clean and bright – replace the relay ifin any doubt and do the same for the fuse,Ideally measure the pressure at the inlet to the main engine fuel pump and ifthis is low check the pump as described and also consider changing the fuelfilter as if this partially blocked this too will reduce pressure. If both of theseare OK then also check the connections to the EGR valve, if either the vacuumpipe of electrical connection are damaged / corroded then the EGR can be on alltime which certainly will hurt performance. Its also possible that its a fault with the EGR valve so its worth removing the valve and cleaning it out with brake cleaner, if it looks particularly clogged then replace it. If this is OK then check the small vacuum lines to the turbo and its connected control solenoid onthe bulk head, any cracks or leaks can give turbo issues and its best to havethe boost pressure measured actually measured with a boost gauge to check thatthe turbo is healthy and that the sensor is reading correctly If its a variable vane turbo (they’ll be an actuator on the turbo body - but not a wastegate) then check its vacuum pipework as above and check the connections to the diaphragm / solenoid valve Also worth checking that the glow-plug relay is switching off as they can stick on and leave the glow plugs also on - on some cars this can force it into limp home Also worth considering adding a bottle of injector cleaner into the tank as a clogged injector nozzle will reduce power andgive poor combustion - the next stage on from this is to remove all the injectors and have them ultrasonically cleaned and flow checked Also check all the high pressure hoses post turbo/s for any split hoses or cracked metal pipes,also check the ends of the intercooler as its not unheard of to pop the end caps off under high boost.
Matt and other Mercedes Specialists are ready to help you
Customer: replied 1 year ago.
Good service
Expert:  Matt replied 1 year ago.
glad to help