Think I need a new starter (2002 ML320)
 

Our 2002 ML320 is having starting problems.
In the last week it has been failing to start 1st time. The starter cranks but the engine doesn't catch. It usually starts OK on the 2nd or 3rd try - but there is a definite smell of burning in the air when it does start, which I suspect is insulation in the starter motor.
It's a Bosch starter so I figure at 88,000 miles it's on borrowed time - I've already replaced the alternator.
Once the engine starts there's no stalling issues - so I don't suspect the CPS although I plan on changing it at the same time..
How dificult is it to change the starter on one of these ? I've changed starters on older vehicles, are there any problems with obstructions etc ?

I would change the CPS first. Don't think its the starter. My 2 cents. ;)

Cps
 

I just checked and discovered that the ML320 has the same CPS as my SLK. If I can track down the E8 socket I'll swap 'em over tonight.

Changed CPS and starting is even worse !
 

When I fired up the truck yesterday afternoon I got a CEL with the p0335 code: CPS !!
I went to NAPA last night to buy the 1/4" drive E8 socket for the CPS exchange and they actuallly had a CPS on the shelf for $67 !
So I didn't have to mess with my SLK to do a swap.
After locating the CPS on the ML320 It took me about 15 minutes to swap it out - thanks to this board.
The truck fired up at the 2nd time of asking and ran OK.
But this morning it took several attempts to fire up and I briefly saw the word error on the dash display. I'm still leaning towards the starter, anyone got any other ideas ?

Real cause of the problem - not the starter
 

Well I found out the real cause of the problem.
After another batch of failed starts at lunch time I followed my nose to the source of the burning smell. I found that the red plastic cover on the positive battery terminal had a melted spot in it. Additionally there was a small spot of melted plastic on the battery case. I checked the main terminal post clamp, it was tight. The clamp has 3 secondary threaded studs which are used to connect the leads. On one of these studs the nut was loose which I assume was causing a bad connection and arcing which was melting the plastic and disrupting current flow to the starter. I just called Phil at Fastlane to cancel my starter order. He was a real Gentleman about it - told me to refuse delivery.

Good catch........................... @ least you shoudn't have any CPS problems for a while and you saved a bunch of $$$$ by not having to go to the dealer/shop. ;)