a lot of people just disconnect the EGR's on things like shoguns etc. Not sure if you want to do that though.
Jay
Jay
Dieselman
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jaymanek said:
You can't do it. The MAF picks up that it's not working and the ECU selects limp home mode.
silverarrow
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yep go for a maf i have seen that if you over fill the engine with oil it is drawn into the maf and gives iffy readings but no fault on diagnostic check my old audi 1.9tdi did the same thing as yours but stealership (not as bad as mercedes) lol said the usual no code no fault burt change the maf did you know if a bosch part no is on the maf as mine has you can order direct fron andrew page ltd motor factors who deal direct with bosch various stores in uk i think maf for mine was £100 all in oh they also did head lamp lens for £25 no £50 from stealership
Still smoky!!
so far we have replaced the MAF, run 1000 miles with high concentration of injector cleaner additive, replaced the turbo to intercooler flexible hose as it was showing signs of a small leak, had the MB diagnostic check and all to no avail. The car did suffer from an apparently common engine mount breakage about two years ago, is there any chance that the EGR vacuum pipe is leaking,thus causing the EGR not to close a low revs/high load and leading to smoke? I am told that egr only closes a low revs/high load in response to inlet manifold vacuum. Smoke only happens a low revs under load.
so far we have replaced the MAF, run 1000 miles with high concentration of injector cleaner additive, replaced the turbo to intercooler flexible hose as it was showing signs of a small leak, had the MB diagnostic check and all to no avail. The car did suffer from an apparently common engine mount breakage about two years ago, is there any chance that the EGR vacuum pipe is leaking,thus causing the EGR not to close a low revs/high load and leading to smoke? I am told that egr only closes a low revs/high load in response to inlet manifold vacuum. Smoke only happens a low revs under load.
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Dieselman
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The EGR valve should close at high rev and load conditions. The MAF should pick up if the EGR is stuck open or closed.
By a puff of smoke do you mean a single blast when the engine comes on song. If so it will be down to the soot being expelled from the turbo and cat.
If the smoke is mainly there I would have the injectors tested and flow ballanced.
By a puff of smoke do you mean a single blast when the engine comes on song. If so it will be down to the soot being expelled from the turbo and cat.
If the smoke is mainly there I would have the injectors tested and flow ballanced.
silverarrow
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how about obtaining a maf from another car and trying it out
The MAF has already been replaced with a new one.
The Mercedes diagnostic injector check showed one injector (No 6) giving a reading of 1.15 and they tell me that the fault level is a reading of around 5!!
It is a serious puff/cloud of smoke at low revs and high load, typically pulling off ( which is normally in 2nd gear like most automatics) and then it clears. I can nearly eliminate the smoke output by driving it as a manual, starting in 1st and keeping the revs over 2K. If I drive along say in second gear at 2k rpm and floor it.. No smoke visible.
what about the vacuum pipes to the EGR?? Can they be easily tested?
I found this on the web!! http://www.fordmondeo.org/ubbthreads/showflat.php?Cat=0&Board=Diesel&Number=341282&page=0&fpart=2
The Mercedes diagnostic injector check showed one injector (No 6) giving a reading of 1.15 and they tell me that the fault level is a reading of around 5!!
It is a serious puff/cloud of smoke at low revs and high load, typically pulling off ( which is normally in 2nd gear like most automatics) and then it clears. I can nearly eliminate the smoke output by driving it as a manual, starting in 1st and keeping the revs over 2K. If I drive along say in second gear at 2k rpm and floor it.. No smoke visible.
what about the vacuum pipes to the EGR?? Can they be easily tested?
I found this on the web!! http://www.fordmondeo.org/ubbthreads/showflat.php?Cat=0&Board=Diesel&Number=341282&page=0&fpart=2
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INJECTORS REMOVED
Injectors were removed and cleaned/tested for spray pattern, certified as OK and refitted. No change in smoke pattern/emission. Vacuum pipe from egr valve to actuator checked, no leak!
It seems I have exhausted the resources of this forum. If I ever find the problem, I will post the result. Thanks to all who offered advice.
Injectors were removed and cleaned/tested for spray pattern, certified as OK and refitted. No change in smoke pattern/emission. Vacuum pipe from egr valve to actuator checked, no leak!
It seems I have exhausted the resources of this forum. If I ever find the problem, I will post the result. Thanks to all who offered advice.
EGR Valve replaced (in desparation!!) and hey presto problem cured, at last. Clearly the malfunctiong valve was feeding exhaust gasses, which contain no oxygen, into the inlet thus resulting in incomplete combustion at low revs and smoke is the inevitable result in a diesel engine.
