ax7146

I have a 2008 Mercedes ML550 that sometimes has issues starting. I have the Auto Start option. When I push the Start button, sometimes it takes several seconds for the engine to start (long crank) and/or the engine doesn't start at all & stops cranking. When the engine doesn't start at all and stops cranking, on my 2nd attempt to start, the engine always fires right up. This is an intermittent issue. My battery is only a year old and I had the dealer check the battery and it is ok. It appears gas is not getting to the engine to start sometimes so it may be a fuel pump related problem. Any help and/or suggestions are appreciated, thanks.

Anthony550

Mine is doing the same thing. Sometimes it starts fine but once in a while it will crank for a while before it starts.. I was wondering if you found out what was causing this yet?

ax7146

I had to replace the fuel pump & fuel filter.

Anthony550

Thanks! This will be my next project I guess

dtownkennel

Seems like my 09 ML550 is doing the same thing at 65000 miles.
Anthony did you ever get yours fixed? Is it an easy diy???
Btw thanks for the advice over the years. My car seems to have the same problems yours has but 6 months to 1 year behind.

Ax7146 how much was it to do at the dealerShip?

Anthony550

I didn't replace anything yet but I poured a bottle of Chevron/Techron fuel injector cleaner in the tank and it has been starting fine ever since. I was going to wait until it started acting up again to replace the fuel pump but it has been starting good.


I also had a misfire on cylinder 5 code and had to replace the ignition coil but I don't think that had anything to do with the starting issue.

dtownkennel

Great that means my ignition coil is next hahaah, I guess I'll try the injecter cleaner next see if that helps. Sometimes I can go for a week and nothing then all of a sudden for a whole day it happens every time I start the car.

Things I fixed or replaced with maintenance so far:
Powersteering resevoir
Rear seat belt
Brakes and rotors
Oil and air filters
Still haven't replaced trans Fluid like you have though. Anything else you've done maintenance wise I should be doing?

Thanks in advance Anthony.

Anthony550

The only other things that I have done is replace front and rear differential fluid and flush out the brake fluid.. The DOT4 brake fluid is supposed to be changed every 2 years.