E320cdi won't go above 4200rpm.

[Markieboye]

noticed occasionally over the past week that the car (W210 320cdi) wont rev past 4000rpm whilst driving.
If you take it up steadily then it will stutter and then drop off. But if you drive it hard then the engine seems to just die - well not quite but the revs drop to about 2500.

Normal driving is fine, mpg is not affected, kick down and general power is good apart from when you hit 4000rpm.

I have swapped out the MAF with a genuine MB one - no change.

Changed the fuel filter and that improved things a little as it'll go up to about 4200rpm but still does the same thing.

I have got it booked in for a diagnostics check tomorrow, but was wandering if anybody has any ideas ?

cheers
Mark

 

[television]

This is a hard one Mark,,you have changed the most likely things,,so it has to be a fuel related fault,,I hope that you post back wit what is wrong

 

[Markieboye]

Thanks Malcolm,

I hope it's something simple. I also think that it's a fuel issue - maybe either feed pump or high pressure pump are not giving enough.

I had another look and when I bring the revs up (standstill) it will do exactly the same thing. So my feeling it that a senso has gone bad and is telling the ECU that the car is not moving, as I believe that they have a rev limiter when the car is stationary.

Mark

 

[turbopete]

ive no knowledge of the 320 cdi engine, but i know dads 220 cdi doesnt rev much above 4200 anyhow! 4500 if its lucky!

 

[Alex Crow]

see what you get on the diagnostics. my bet is p1470.

 

[Markieboye]

see what you get on the diagnostics. my bet is p1470.

And that is ?
And what's the cause of it.

 

[Alex Crow]

p1470 simply relates to low boost pressure. the causes of low boost are many and varied, eg; blocked filter, split hose/intercooler, sticking egr valve, leaking intake manifold, blocked cat/s, vacuum control fault or shot turbo. so you see it is almost impossible to guess here what is wrong, i would have guessed maf sensor first, but you have tried that.

 

[Markieboye]

Thanks A-P

If it does come back with the code you say, then I'll be getting the spanners out Thursday/Friday and working through your list of possibles I'll probably start with the EGR, as at 192000 miles it might just need a clean out

Thnx
Mark

 

[Markieboye]

Well the codes came back as :



P1354-032 Synchronization between cranckshaft and camshaft Plausibility

Well this one came back as soon as engine was started, and i think that this is just due to the amount of miles (192k) the engine has done and some slack in the timing chain.


P1403-032 Exhaust gas recirculation Negative control variation [ Exhaust gar recirculation rate is too low ]

I think stat this is the one that is causing the problem, but not sure if this is a sensor failure or just that the egr is totally chocked up.

 

[Alex Crow]

yep, that p1403 code will be the one. could be a jamming valve, a split diaphragm, a u/s vacuum modulator or a vacuum supply problem. try removing the pipe at the yellow joiner piece and checking for dirt inside, if it is even slightly sooty the diaphragm (or at least one of them, there are two) is split. does sound like it is jamming though, cleaning out may work but i have replaced several on the 320 engines...

have a look here at the code ref-

http://www.startekinfo.com/dtc/dtc/...rt=648&dtc=1403&id=356&parentid=33&modelyear=

 

[Markieboye]

yep, that p1403 code will be the one. could be a jamming valve, a split diaphragm, a u/s vacuum modulator or a vacuum supply problem. try removing the pipe at the yellow joiner piece and checking for dirt inside, if it is even slightly sooty the diaphragm (or at least one of them, there are two) is split. does sound like it is jamming though, cleaning out may work but i have replaced several on the 320 engines...

have a look here at the code ref-

http://www.startekinfo.com/dtc/dtc/...rt=648&dtc=1403&id=356&parentid=33&modelyear=

Thanks A-P

do you have a pic of the pipe you are referring to for the yellow joiner , or even a pointer in the right direction.

cheers
Mark

 

[Markieboye]

Well I took the EGR off today to see what the state of it was:

and found out that the person before me had blanked off the EGR, where the heat exhanger bolts to the head, so no more nasty stuff getting to the inlet

After I cleaned it up it was looking a lot better

Gave the two intercooler pipes a wipe out as well whilst they were off.
I also cleaned the sensor that fits into the metal pipe between the intercooler and the EGR.

The diaphrams on the EGR are in goot knick and working fine. The vacuum regulator seems to be producing a vacuum to the egr.

All back together but still the same; BUT I did notice that it was smoking a bit this morning under heavy accelaration (engine fully hot)

Currently I am putting it down to one of three things:

vacuum regulator - but seems to be okay

EGR valve sensor

Sensor on the intercooler pipe

 

[Markieboye]

Well I have spent some time on this and have really got no further

I have had it into a dealers in Sheffield and they have done some diagnostics and can not find any obvious fault, other than the P1354 code. They had even replaced the cam sensor, as a test, and that did not change anything. They have come back with that the chain has stretched

I have spoken to my local dealers (Stafford) and they are, currently, have said that they can NOT see how the chain on this engine could stretch and their techies are saying that it has got to be something else causing the problem.

Another thought I have had is could it be the high pressure fuel pump :?: as that is driven off the inlet cam and if there is wear it may not be delivering enough fuel at that high RPM :?:

 

[Alex Crow]

forget the pump, at high rpm it spins plenty fast to provide fuel, and low fuel pressure with engine running will always log plenty of codes. there was a known fault with some earlier cdi modules throwing synchronisation codes, but i understand this was only with 611 and 612 engines. cam timing is easy enough to check if the injectors come out ok. injectors out, rocker cover off and check marks against crank. this will be done at tdc or 20deg or some such, but if you are keen to have a go i am sure we could provide specifics.

have you had a look in the egr vacuum pipe for soot? or tested the egr diaphragms for leaks? you must do this!! that yellow joiner is just in the vacuum pipe next to the actual valve, unplug it and ensure it is perfectly clean inside. if it is sooty this implies leaking diaphragm and soot ingress, causing various knock on problems.

you do know that synch code can be logged after an extended period of cranking without firing up?

 

[Markieboye]

EGR has been checked, cleaned and all okay, no soot in pipes, and diaphragms are all okay. The EGR was actually blocked off between the head and the heat exchanger :smile:

the code re-appears at each start up.

 

[Alex Crow]

THE code being the p1354? still thinking about this one but i would have a check of the timing myself.

 

[Markieboye]

THE code being the p1354? still thinking about this one but i would have a check of the timing myself.

Sorry, yes that code. deffo looking into checking the timing. about 3hrs from the dealer and an extra 2hrs to replace the chain. to do the whole thing comes in at £700 inc parts.

Seen your post on the other side about tensioner.