SsangYong Rexton 2.7 CDi Mbenz 2.7 OM647 with Delphi HPCR

heliosuk

Hi people, a couple of problems in one here!

Knocking noise suddenly heard from next doors Rexton ( 2.7 5cyl 20V cdi). He took it to a garage who claimed to diagnose problem as engine gone bang. Total rubbish as car performs well, is noisey though and there is no evidence that he carried out the work on the invoice.

Next door asked my help. Listened and noise definately top end related. Sounds like an old diesel, but not as quiet as it should be. Isolated knock to predominantly No 2. Possibly hydraulic tappet but reality a bit too noisey. Removed cam cover and no apparent damage. In fact very clean valve drive train. Swopped No 1 injector with No 2 to see if noise transferred as injector pipe on No 2 pulsing quite heavely. Colleagues reckon noise is injector related i.e. heavy leak causing semi hydraulicing. Put all back together and now it won't start. Need to get it running to confirm if an injector fault.

Can only think that next door put windows down a fraction when top end apart which means that ECU would not have found injectors, cam position sensor, air flow meter and manifold pressure sensor so has shut itself down.

Am I on the right track as have double and triple checked everything and nothing should stop it from running. Even gone to extent of manually bleeding a self bleeding system.

Interesting one this so any ideas welcome!!

Thanks.

ch427 · Posted: Wed May 06, 2009 7:41 pm Post Subject:

i reckon your ecu may need to be taken though a reset procedure,is that the mercedes engine?

heliosuk · Posted: Wed May 06, 2009 9:10 pm Post Subject:

Yes it is. I've identified it as an OM 647, possibly 961 varient. Only difference is I think, that this version fitted to the W211 range has a Bosch HPCR system and the Rexton uses Delphi. Personally I like the Delphi as is a very neat and compact system plus you can get the valve train cover off without removing the injectors.

I'm told that on the Bosch system this loud tapping/knocking is common with failing injectors though there seems to be little experience with the Delphi system.

Will try to find someone to read and reset tomorrow, then once running it should be easy to confirm where the knocking fault is.

ch427 · Posted: Thu May 07, 2009 6:45 pm Post Subject:

i dont think ive heard a quiet mercedes diesel!

heliosuk · Posted: Thu May 07, 2009 7:26 pm Post Subject:

Turns out injectors are coded to ECU so put them back in correct order but still won't start.

Is any diesel quiet?