mrwhattie

Hi everyone,
I've recently had a problem with my ML270 (twice) which has got me totally puzzled.
While driving along at normal speed, the power disappears and it feels as though it has gone into limp mode, but it isn't limp mode, it will still continue to reach speeds of 120kmph if going downhill but with no power uphill. On both occasions I stopped the vehicle for about an hour and when I restarted there was a big puff of black smoke and the power was back to 100%. I've had it to the indi, who had it on the machine checking for fault codes and there were none stored. My only thought about what the problem could be is a blocked exhaust muffler.
Any thoughts from you guys, and has anyone had a similar problem?

mrwhattie

Looks to me like I'm the only one who has experienced this problem

art_arev

Have your CATS checked. There is no way you don't have codes stored. Find a indie with a pro level scanner capable of reading MB codes.

mrwhattie

I removed the CAT about 5 years ago, The indi I took the vehicle to is an ex mercedes mechanic with all the latest equipment. After checking the vehicle on the scan machine he took the car for a drive and when returning put it back on the machine and still not fault codes. After thinking about the problem, the only thing I can think of which is causing the problem, must be a blocked muffler. I am going to cut it open to see if that is where the problem is.

Paddymlw163

Hi
I had this problem twice.The first time the power went completely and did not return even when the key was turned off.it turned out to be the air flow sensor.
The second time,which sounds like yours was the swirl flaps in the inlet manifold.
Hope this helps

mrwhattie

Thanks for you feedback Paddymlw163, I have been suspecting the swirl flaps to be the problem for some time, but just don't have the time to take the inlet manifold off and check them, but I think I will have to bite the bullet and tackle the job. I have also got an E270 which will need to have the swirl flap delete done as well.

mrwhattie

Hi everyone, some feedback on my no power problem.

I'm working away from home so this is the reason for the long delay, when I got back home I decided to tackle the problem head-on.

I thought that the turbo may be the major problem as I was getting a low boost pressure fault code. I replaced the turbo core, changed the mass air flow meter, replaced the boost pressure sensor, removed the intake manifold and did a swirl flap delete, removed and flushed out the intercooler due to too much oil (in my opinion) checked all the boost pipes too and from the intercooler for any leaks, replaced the diesel filter and pipes to the high pressure pump, replaced all the green "O" rings on the fuel pump pipes, and still got the low boost pressure fault. There was only one more thing that it could possibly be - a vacuum pressure converter valve which controls the turbo actuator (A000 545 05 27) - I noticed that when I started the car, the turbo actuator arm wasn't pulling down like it is supposed to do. Once this was replaced I had my ML back in action again
I also replaced the vacuum pressure converter valve controlling the EGR valve as this also seemed not to be working (I did try and swap it with the turbo vacuum converter valve with no success.)
In my opinion the swirl flaps being removed, doesn't make any difference on low speed acceleration. I did a short 200kms run and had a 9.4L/100 consumption, even though I did some high "testing" speeds.

Gabriel w163

Jumped into limp mode check the ecu why