W163 ML270 Starting Problems

[thefair1973]

Hi All. I have a 2004 ML270 that’s being problematic starting when cold. It starts first time but almost immediately cuts out. It then needs another 4 or 5 cranks to start it. Problem is, it sometimes kills the battery by the last attempt so I then have to charge it. It’s been in to an independent MB specialist who’ve said it could be all manner of things but wasn’t worth troubleshooting due to the cost Vs age of the car. initially, the glow plug light was staying on after starting. Star was reporting glow plug 4 issues so I had that replaced. No change. It also reported MAF issues but I’d had that replaced at least twice in the last few years due to power and kickdown problems. As I didn’t have those, I didn’t replace the MAF.

Is it possible that the MAF could be causing these problems starting? Once I’ve started it and driven so the engine is warm, it starts first time when I come back to it after being in a shop for example. I just wondered if anyone had any ideas? Happy to get a MAF from ECP or similar and follow the YouTube videos to swap as it looks simple. Anything else and it’s a garage visit.
Thanks in advance.

 

[norfolkboy]

my 2002 ml270 is doing exactly the same, can't find anybody near me to troubleshoot, so i think the breakers yard is calling...

 

[Mark A]

Check the fuel supply lines to the HP pump for air bubbles- very common to have air leaks on the LP side of the system. Plenty of articles on here to show seal replacement and also the HP pump itself. Seals are a cheap fix, but if that doesn’t work I’d get an indie to check it over before buying a replacement pump.

 

[Taffy7hfa]

As above air leaks on the pipes going to the tank often cause starting problems, pennys to replace seals if that is the problem. Have to say not a big fan of garages that have an "its not worth it mate" attitude . By modern standards these cars are not that complex and can often be repaired very cheaply if you know what your doing. MAF issues wont affect start-up. Glow plugs/relay are a simple job and should not be a reason to bin the car off. If you really want to keep the car invest in an ICar Soft MBll.

 

[norfolkboy]

thanks for that, gplugs relay and proper socket for removal ordered, £65 all in to give it a go sounds fair, releasall and heat from tomorrow..

 

[oigle]

Glow plug operation in a 270 motor is unnecessary for normal start and running. They are only there as an antipollution measure.
If you want to exclude MAF, see thread by stumo. I would very much support the air in fuel lines scenario.

Ian.