Limp Mode and EGR issues D40

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Tom1

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My 82 yr old Dad has a D40 that started to blow a lot of white smoke then went in to limp mode. His mechanic replaced some injector pipes and a filter?, improved a little for a short while, problem came back with car in limp mode,then mechanic replaced the exhaust system, problem still there, now mechanic says computer needs re mapping. I called in to see mechanic today, he said the re mapping is to clear the EGR which is blocked, i was under the impression the EGR could be cleaned manually at the manifold. I think mech has been clutching at straws all the way along, either taking dad for a ride or not really knowing what to target. Does anyone think the re mapping is the next step? thx for any comments. Tom
 
Remapping the ECU won't do a thing to clear the EGR. More importantly, some of us deliberately block our EGR! Replacing the exhaust for white smoke, I'm not sure that's a good move.

White smoke is caused by overfuelling. It could be the car trying to do a DPF regen, the injectors shouldn't be a problem if they were replaced (they have to be registered with the ECU but surely the mechanic did that). The MAFS might be dirty.

It's definitely in need of visiting someone else, if only for their opinion. Going off error codes may not be the best way to resolve the issue - if the car is presenting errors to do with the exhaust and the injectors, it could be an erratic sensor connection or even something like dirty battery terminals.
 
Thanks Tony, after some more digging, questioning and probing, it looks like it is an issue with the DPF. Looks like it may have been a modified and the re mapping is to fix the computer looking for the DPF. It has been a long way to get to this point it appears, i will look for a new mechanic for him now.
 
You might not need to remap the ECU to fix the DPF issue. Write a message to auggie on this forum. For around $500-600 (not sure of current pricing) he can send you a pair of replacement sensors that make DPF problems just disappear. Yes, they worked for me!
 
And also, give that mechanic the arse. Replacing a full exhaust to help the white smoke issue is just a blatant money grab. Sounds like they are just "eliminating" the causes that are least likely to be contributing first just to make some money.

Or they are just plain dumb.
 
White smoke can be caused by a number of issues, over fueling generally when the engine is cold, generally when the engine is a operating temperature then it becomes black smoke, low cylinder pressure or low compression will have the same effect as cold running, the wrong fuel like too much wax in the fuel or oil getting into the intake system. Perhaps take a look there, issues like blow-by, turbo seal failure, valve stem oil seals, pooling of oil in the intake and then a rush of oil ingestion, also coolant leakage into the combustion chamber like a leaking head gasket.
Leaky injectors, failure of the piston rings being unable to control the oil on cylinder walls and even the wrong weight oil could possibly cause issues.
If the vehicle has a DPF then an issue with the burn off may possibly cause white smoke.
 
If the vehicle has a DPF then an issue with the burn off may possibly cause white smoke.

Absolutely, had this happen to me. And it did it once as I was being pulled over for a random breath test. I turned off the engine to stop the smoke, and when I restarted it there was none - definitely a DPF regen issue. It was fixed by using the replacement sensors from Auggie.
 

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