Never, NEVER shirk preventative maintenance!
 

What a Memorial day weekend! :rolleyes:

Took the ML and had it fully loaded heading out from Texas on to Missouri.

Ignored spurious signs of engine problems (and the CE light) over the course of six months since the truck is driven infrequently, and therefore, the problems cropped up just as seldom.

Reset the CE light and went on our way. Things went fine until Friday, when we ventured out onto a lonely country road to avoid holiday traffic on construction-laden I-70.

The ML hiccupped a couple of times then finally quit completely. Figured it was a dead fuel pump.

Took 2 1/2 hours to get a tow truck dispatched out to that remote area, then towed 90 miles to the nearest Benz dealership. It was nightfall by then.

Family showed up at the same time thankfully, so we transferred our stuff and were on our way (sans ML).

Due to the holiday, it didn't get looked at until Tuesday, and they confirmed the fuel pump diagnosis. MB changed the fuel filter later and they offered to do the retrofit kit as well while they were at it. I agreed, but some of the parts were on backorder, so I just had them put the old filter kit back in :mad: (now I have to do this all over again later, pull back seat out, etc...).

Pulled up a page worth of stored codes including the bad MAF (which indicated that the ambient temp was -40 when started), hence the poor performance I have noticed recently! Got it replaced as well.

We were back on the road two days later than planned (and $1100 lighter). What a vacation!

ML runs a LOT better than it has been!

I'm usually very meticulous about car maintenance, but with all of the stuff occupying my time and wallet, I let things slide this year...BIG mistake!

Don't let it happen to YOU! :eek:

On a similar note, I bought my 560sel a couple years ago with 135k on the clock. It needed one fuel pump, and although everyone suggested that I replace both (to be safe), I replaced only the bad one...

2500 miles later, in the middle of nowhere, my car felt like it ran out of gas. Coasted to a stop, waited a minute, and then tried it - started and ran fine, for about 20 seconds, and then "ran out of gas". We scratched our heads for quite awhile (most of a day), and then finally removed both fuel pumps and bench tested them, which showed the fault.

Our problem with diagnosis is that since the pumps are mounted together, when one is buzzing it feels like they are both running...

The clincher in the diagnosis process was when we hooked up a fuel pressure gauge - this showed "normal" when we started it, and then slowly went down to (below 40psi where it quits...)

-David

I'm curious (especially ML owners)...what is the life span of these fuel pumps? My ML was out of factory warranty, but I wouldn't have conceived that sort of failure at under 57K? :confused:

No prob with the W124...140K+ miles and still going strong...

I think the moral of this story is not about a lack of preventative maintenance, but about the wisdom of not ignoring a check engine light.:cool: