Apologies in advance for the length of this but thought it best to explain what has been "tried" ....
Friends 2005 C220CDI OM646 with the euro 4 DPF, mileage approx. 157k
They have had the car for a couple of years and in that time things have got progressively worse when they have tried to fix the problems. The car initially had leaking injectors seals. When this was repaired they replaced number 2 and 3 injector with 2nd hand ones but never had them coded to the car. They actually worked fine but the fuel economy was never what I would consider normal for a diesel only really averaging around 35-38 mpg doing mixed driving. They decided to get it remapped and at the same time have a DPF solution done from what I understand both the CAT and the DPF have had their innards smashed out so are somewhat free flowing and the original cans all re-installed back on the car so everything looks original for MOT etc... Anyway remap was completed by a reputable tuner and to be fair mpg seemed to improve to around 41 mpg average.
Sadly the injector seals appeared to have failed on two of the injectors which were replaced (approx. 20k miles later) at this point the injectors were removed and took the opportunity to have the injector tips dismantled and cleaned in a hydro-sonic tank to refurbish them. They have since been re-installed and appropriately coded to the ECU (previously two of them were not)
Since then there have been a number of issues...... The car is now difficult to start when cold can take a couple of cranks to fire into life and when it does it almost feels completely gutless and sometimes doesn't want to rev. After a couple of minutes at most it is fine. The other noticeable issue is the fuel consumption has taken a dive it is probably at best doing 30-34 mpg. They asked me what I thought having had a few Mercs over the years but to be honest I said I have no idea and at a guess it could be the injectors or the remap as since the injectors have now been coded to the ECU I was not sure if that would change things given the remap was done when two of the injectors were not coded to the car??
Oh he has removed the MAF and cleaned it with brake cleaner and re-installed and that didn't seem to do anything.
I did say I would post on here in the hope that someone with a bit more diesel savvy would point him in the right direction. He has done a leak down test this was a timed 3 minute run with the bottle on the left being injector 1 (front of engine) and the rest following that consecutive order. As previously mentioned injector 2 and 3 were 2nd hand but clearly are leaking off less. Does it look like the injectors are the issue. I could also see and he reported smelling some diesel fumes in the car I can see where the DPF and CAT join is the tell tale black smoke marks so it looks like it is leaking at that join and will need re-sealing. No evidence of injectors leaking and he said that the thicker Honda copper seals were used when the injectors were put back in. Picture shows the diesel leak off test if that is helpful.
Any thoughts greatly appreciated there are absolutely no codes or error lights when the car is connected to a OBD reader.
Does he need properly refurbished injectors and possibly another remap afterwards is ultimately what is being asked or could it be something else??
Friends 2005 C220CDI OM646 with the euro 4 DPF, mileage approx. 157k
They have had the car for a couple of years and in that time things have got progressively worse when they have tried to fix the problems. The car initially had leaking injectors seals. When this was repaired they replaced number 2 and 3 injector with 2nd hand ones but never had them coded to the car. They actually worked fine but the fuel economy was never what I would consider normal for a diesel only really averaging around 35-38 mpg doing mixed driving. They decided to get it remapped and at the same time have a DPF solution done from what I understand both the CAT and the DPF have had their innards smashed out so are somewhat free flowing and the original cans all re-installed back on the car so everything looks original for MOT etc... Anyway remap was completed by a reputable tuner and to be fair mpg seemed to improve to around 41 mpg average.
Sadly the injector seals appeared to have failed on two of the injectors which were replaced (approx. 20k miles later) at this point the injectors were removed and took the opportunity to have the injector tips dismantled and cleaned in a hydro-sonic tank to refurbish them. They have since been re-installed and appropriately coded to the ECU (previously two of them were not)
Since then there have been a number of issues...... The car is now difficult to start when cold can take a couple of cranks to fire into life and when it does it almost feels completely gutless and sometimes doesn't want to rev. After a couple of minutes at most it is fine. The other noticeable issue is the fuel consumption has taken a dive it is probably at best doing 30-34 mpg. They asked me what I thought having had a few Mercs over the years but to be honest I said I have no idea and at a guess it could be the injectors or the remap as since the injectors have now been coded to the ECU I was not sure if that would change things given the remap was done when two of the injectors were not coded to the car??
Oh he has removed the MAF and cleaned it with brake cleaner and re-installed and that didn't seem to do anything.
I did say I would post on here in the hope that someone with a bit more diesel savvy would point him in the right direction. He has done a leak down test this was a timed 3 minute run with the bottle on the left being injector 1 (front of engine) and the rest following that consecutive order. As previously mentioned injector 2 and 3 were 2nd hand but clearly are leaking off less. Does it look like the injectors are the issue. I could also see and he reported smelling some diesel fumes in the car I can see where the DPF and CAT join is the tell tale black smoke marks so it looks like it is leaking at that join and will need re-sealing. No evidence of injectors leaking and he said that the thicker Honda copper seals were used when the injectors were put back in. Picture shows the diesel leak off test if that is helpful.
Any thoughts greatly appreciated there are absolutely no codes or error lights when the car is connected to a OBD reader.
Does he need properly refurbished injectors and possibly another remap afterwards is ultimately what is being asked or could it be something else??
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