E200cdi 2003
 

I wonder if anyone has had a popping sound in the exhaust of a merc diesel. At first it sounded like a rear shock absorber but it is coming from the exhaust. There has been a loss of power but not too much and the car is running ok just not like before. Some of the mechs say it is the catalyitic converter (no garantee) but it cost a $1000 to replace and I don't want to do it and find out it is not that.

In the US if the catalyst is not working the O2 sensors would be required to set off the CEL.

Don't know about emission laws wherever you are.

If it is a clunk when hitting bumps it may be as simple as an exhaust or muffler hanger.

Mercury makes a diesel? :confused:

Was the Merkur in Europe a Mercury? Would that be affectionately known as a merk???:rolleyes:

British Isles
 

F.I. + Terry,

cmdr759 is in the British Isles (I think)
The E200 CDI "Ain't never been offered to us here".

"MERC" is British patois for a Mercedes.

Sorry for not being totally specific but I can appreciate you having a go at the British but I am American living in Romania. The E320 would be an equivalent offered in the states just mine has the smaller 2.2 liter motor.

I will look for the sensor but I don't see any warning from the fault computer.

D.C
Romania

Wasn't suggesting the o2 sensor is bad (located on the exhaust aft of catalyst) but that if the catalyst was bad that it should be telling you.

Expect that because you also stated thinking it was initially a shock noise and then narrowed in on the exhaust that it has something to do with the hangers. One is next to muffler. W/O looking, I think you need to pull trans pan to see the second one.

Could also be one of the plastic sway bar links. When the bushings get bad they can click or groan sometimes.

Your catylst (Mechanic's Percieved)
 

Dieselman on the UK forum suggests...

Drill a hole in the exhaust downpipe and connect a pressure guage via a self retaining nut.
If the cat is blocked there will be significant pressure in the exhaust, if not it will be low pressure.