Mercedes ML 270 CDI red hot cat
Discussion
Had an issue with my 03 Mercedes W163 ML 270 CDI cutting out last week on the motorway, was stalling over 3k RPM with EPC light showing, restarting was the same and we were getting a bang/rattle from engine so recovered it to home
Fast-forward to this week got time to do a bit of looking what was going on, fair bit of grey smoke coming out the back starting the car up & noted a lot of white/grey smoke under the air intake so stripped all air intake box away
On running car now can see the cat getting red hot as below and a good bit of smoke coming from the fitting between exhaust manifold and turbo
So question now is .... is the cat blocked or is unburnt fuel making it into the engine and whats the best way to find out?
Pic below is after turn off so we can see here exshaust is still exiting near the turbo after shut down
Fast-forward to this week got time to do a bit of looking what was going on, fair bit of grey smoke coming out the back starting the car up & noted a lot of white/grey smoke under the air intake so stripped all air intake box away
On running car now can see the cat getting red hot as below and a good bit of smoke coming from the fitting between exhaust manifold and turbo
So question now is .... is the cat blocked or is unburnt fuel making it into the engine and whats the best way to find out?
Pic below is after turn off so we can see here exshaust is still exiting near the turbo after shut down
Edited by Captain Answer on Friday 18th December 14:29
Edited by Captain Answer on Friday 18th December 14:32
GreenV8S said:
Did this develop gradually? That would suggest the exhaust has become blocked. A collapsed cat or blocked DPF might cause that if got bad enough, but that doesn't happen suddenly. If you have a DPF and pressure sensors on that you could tell whether that is what is blocked.
We had a single cut out on the cat about 6 weeks with epc light 6 weeks ago but nothing since.. think I'll take the front cat out and see what's going on insideDrop the exhaust front end & check as one likely candidate would be a blocked cat or cat where the honeycomb has become detached from the outer shell & dropped to partially block the gas path.
Also get your fuelling checked as a very lean mixture will potentially elevate the temperature at the front of the cat.
Also get your fuelling checked as a very lean mixture will potentially elevate the temperature at the front of the cat.
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