W203 220 CDI will only rev to 3k

[merc drivrer]

Hi Guys

As stated in post title car will only rev out to 3000 revs

When car is started from cold and driven everything is fine plenty of lift and boost
After driving for a while this can be half an hour, one hour or maybe two hours, car goes into what seems to be limp mode and wont rev out past 3000 revs even when at idle.

Sometimes switching car off and leaving for a few minutes and starting again everything is fine again.

Other times while driving the car it will sort its self out and again plenty of lift and boost.

Couple of things that I noticed

when everything is fine and car driving well if car is stopped and idling for even just a couple of minutes and I drive off again no revs, lift or boost.

When car has lost revs, lift and boost and I get it on a straight road give it some welly and get up to about 70mph car seems to clear its self.

Car is 2001 c class cdi w203 used as a taxi doing on average 1000 miles a week over 4 night shifts

Car going on star on monday morning, looking for some heads up or some pointers that may help me fix problem myself

Thanks in advance

Jon

 

[ACID]

It could be a few things, such as a sticky EGR valve, split intercooler hose etc, best bet is wait till Monday and get it plugged in and it'll give you a better indication instead of throwing parts at it

 

[merc drivrer]

No don't want to be throwing parts at it

It's just so intermittent at times car can go for for 3 or 4 hours with no problems plenty of lift an boost then the next 3 or 4 hours its all gone

Don't even need to switch car off and on again just fixes its self

Nothing makes it go one way or the other with normal driving only when lift an boost is lost giving it some Welly on a straight road does it return to normal for a while

Jon

 

[merc drivrer]

Hi guys

Update

Car was put on star on Monday showed a maf fault only thing is for two days car was running fine no loss of power or boost garage cleared fault and was good enough to give me a new maf to see what happens

On Wednesday same faults occurred again no power lift or boost and wont rev out past 3000 revs so I changed maf to new one car drove fine for 24 hours then back to same faults again only this time things are slightly different

Car going in an out of limp mode as I drive can do it every few hundred yards or every couple of miles. From a standing start car goes fine lift boost and power and by the time I get to top gear in limp mode

With the new maf fitted the fault will stilled be logged by the car, does the car think there's still a fault even though new maf fitted ? Should I get it back on star, 1 to clear the fault and 2 to see if there are any other faults ? This was the only fault Found by star on Monday

Due to work commitments I can't get car onto star until Monday again. I have a few hours tomorrow morning where I am going to check all boost pipes etc and egr valve

Will keep use all updated and let you how things turn out in the mean time any other pointers would be helpful

Thanks Jon