Whoops1

Hi all,

Any comments / help would be appreciated....

I'm looking to steer my independent specialist in the right direction. My problem is below, but since buying the car, I've had a full service (oil filter, air filter, oil change). The car has had timing chain changed and tightened around 30k miles ago, and has been serviced every year since new. The mechanic tells me that the EGR has been removed and cleaned up and the turbo is clean and clear. I've just had all of the glow plugs changed and the control unit was changed about 2 years ago.

All of this and the car - especially from cold - struggles to get over 1500rpm. It's as if the car is limiting itself to that level. Occasionally it gets up to 2000rpm, but judders like a misfire or as if it is running out of fuel and then settles back to 1500rpm.

I've put some Redex in the tank to hopefully clear anything, but this has been pretty useless.

I was hoping before the mechanic starts "trial-ing and error-ing" and this costing me a fair few £££'s ... Maybe someone had had the same problem and could help me ..??

The next suggestion is that the diesel particle filter is blocked and to try a new product "cataclean" ... Any thoughts..??

I'm not mechanically gifted, but learn loads from these threads and comments.. so would appreciate any (not too technical) please..!!

Thanks for your help in advance..

Diesel Benz

Bring it to an independent who has the Star Diagnosis tool and knows how to interpret engine sensor figures.

Whoops1

Thanks,

Apparently the diesel particle filter is 300% (tolerance is 120% ..!!) full or blocked .. Whatever the term would be for that part...

Would this cause the juddering effect and restriction to 1500rpm..??

g naza

Hi. I know this is an old thread but having exactly the same problem. Would really appreciate if you could tell me what fixed it as I have changed the turbo, inlet flaps motor, MAF sensor, cleaned the intake manifold flaps and nothing helped so far. Thanks in advance

DaveW68

The problem is that you're throwing a bunch of parts at it without having the car properly diagnosed. An hour of diagnosis by a dealer is around $130. Let them scan & inspect it to tell you what's wrong....then do the repairs yourself if you feel so inclined.

g naza

Thanks for your reply. I already had it at the independent mb specialist and the car has been put on STAR. The codes were:
0105-002 CHARGE PRESSURE SENSOR SIGNAL VOLTAGE LOW

2359-001 CHARGE PRESSURE CONTROL. TOO LOW BOOST PRESSURE.

They suggested i change a turbo, an inlet flaps motor and some seals, all of which i did an none helped.

Nuru

Did they check for leaks in the downstream charged air hose that transports charged air from the turbo to the engine? Mine was leaking on my car and it had my car underperforming big time and it was intermittent (<$700 installed). Seems that it was fine after initial start up but soon afterward, it could strike at anytime. It is on the back of the engine in a very tight spot.

g naza

i had a smoke test done on the whole system and no leaks were found

g naza

Exhaust back pressure sensor was faulty and causing the car to not rev over 1500 rpm

Nuru

Glad you found the issue!

g naza

Thanks mate. It did feel good to finally get it back after being down for 5 weeks!

alx

5 weeks to identify a faulty back pressure sensor? It takes about 15 minutes with star/ das.

Change mechanic.

g naza

There was more. The original problem was the turbo itself (one of the impellers was broken), which needed changing. Then there was a problem with manifold flaps not working correctly. And the last bit (1500 rpm limit) was down to the back pressure sensor.

Nuru

Wow. one quick question, after being down 5 weeks do you happen to notice any new audible sounds coming from the engine compartment?

g naza

Not really. The engine runs very quiet and smooth now, very responsive & returns better MPGs. Very pleased with the car now.
I also did not mention in the previous post that at the same time I changed an inlet flaps motor, fuel filter, EGR, plenty of seals and gaskets + coolant.