ML 270 turbo issues - Newbie

[hampshire jock]

i have a ML 270 cdi 2003 49 k - had loss of power - limp mode - so took to local indy MB garage. everything pointed to MAF but wasnt. has a short code diagnostic of P1470 ??? this points to the turbo boost pressure being too high or too low. the turbo whine is definelty intermittant and local indy MB says it will need a full diag scan to be sure of the problem.

Has anyone heard of the is problem before - is it the turbo - if so how much will one of those cost ???? or could it be problems with ECU or software ?

will a full scan uncover the issue - any other suggections ?

thanks i advance

v worried ML owner

 

[psmart]

Heres 2 threads you can look at for background:
http://forums.mercedesclub.org.uk/showthread.php?t=16879&highlight=turbo
http://forums.mercedesclub.org.uk/showthread.php?t=17603&highlight=turbo

Im in the midst of posting a Turbo Replacement DIY for the ML, but to answer your questions, Cost of NEW Turbo, I got one for ~EUR400 original Mercedes off Ebay Germany, its done over 13K since installed and spinning sweetly.

P1470 = Boost Pressure Control Valve Transducer - possible issues you can read in the two links above. The code basically is stating that the ECU is sending a given current (in milli Amps at fixed voltage ~5v) which the ECU expects the BPCVT to move the Turbo actuation arm (which in turn moves the Vanes of the turbo into the exhaust stream) and for the given engine speed, air mass etc, it expects a given boost pressure at the inlet manifold. This isnt happening, so either a fault has occurred with the BPCVT, the vacuum is out of spec or a pipe has come off, the turbo actuator is out of spec or faulty, the turbo is faulty (there has been some occasions where Merc has replaced these turbos because of un-known issues), the intercooler is leaking, the boost pressure sensor is loose or faulty etc.

After reading, post any other info you might know and Ill see how I can help.

 

[hampshire jock]

thanks very much for swift reply.

will look at all the issues you have passed on and see if this solves it.

Definelty intermittant problem as this morning she drove fine.

you mentioned intercooler leaking - how can i check for this

off to halfords to buy a good contact cleaner.

thanks again

 

[hampshire jock]

from reading your latest post abt changing the turbo - this has lead me to notice the following:

the intercooler has a small oil leak - well weep - in the bottom right had corner - could this lead to the problems i am experiencing ?

is the intercooler oil fed from enginie oil ?

again thks v much for your very helpful words

 

[psmart]

Hi,

There should be no leaks from the intercooler, its a sealed unit. A leak would mean that the boost pressure would be incorrect for a given actuation of the turbo, thus the ECU would detect an out of parameter error (ie. it requests the BPCVT actuate the Turbo actuator and expects xPSI at the exit from the intercooler as informed by the Pressure Sensor). This could very well be your problem.

Oil weeps into the system from the crankcase breather seperator (crankcase gases go through an oil seperator and are fed into the turbo compressor inlet) hence you will have oil in the intercooler, how much depends on age and wether the seperator is failing.

Get your wife or friend to rev the engine and listen to hear if gas is escaping, if it is, then new intercooler time.

 

[hampshire jock]

hi
thanks again.
the intercooler rad is at the very front of engine bay - is this correct ?
looks like what i would call a normal engine rad ?
bottom left corner is oily and mucky with a weep of oil

so this is not normal.

looks like its been leaking for a while.

what passes through this rad then ? gas ?

 

[psmart]

hi
thanks again.
the intercooler rad is at the very front of engine bay - is this correct ?
looks like what i would call a normal engine rad ?
bottom left corner is oily and mucky with a weep of oil

so this is not normal.

looks like its been leaking for a while.

what passes through this rad then ? gas ?

The intercooler is in the pic in the link http://forums.mercedesclub.org.uk/showthread.php?t=28522

Basically, you have the radiator for water at the back, the intercooler at the top front, the gearbox oil cooler at front bottom, (from memory you also have power steering radiator and oil cooler). If its the top front radiator, then its the intercooler. Only air passes through it (compressed air from the Turbo Charger) mixed with a little oil from the crankcase breather seperator).

 

[benzdriver737]

ML270 intermittent turbo noise

This may be totally unrelated to your problem, but I was experiencing an intermittent turbo noise.
Noise was only audible when the engine was cold.
Took the car to local stealership, they kept it for a couple of days, then finally told me I needed a new turbo and a new catalytic converter.
Approx. $8000 AUD.

Sounded serious, so I told them I would think about it.
Took the car to in independant diesel workshop, and they told me the exhaust manifold was leaking. (once the engine was warmed up, the leak closed).
Result... new gasket.... fixed problem......

ML270 2002

 

[hampshire jock]

ml270 power loss update

update on power loss

i have been for a full diagnostic and the following code has come up :
p1470-008 - charge pressure control open circuit in wiring signal wire.

does anyone have experience of this failure ?

its going back in for further investigation - but any help gratefully recived - as it may save time - and hence money !!

thanks in advance

 

[Uncle Benz]

Sounds like a faulty boost control solenoid valve to me...

 

[hampshire jock]

Sounds like a faulty boost control solenoid valve to me...

thanks - i will pass this on
its in the garage now
will let you know the outcome

 

[BlackC55]

Vacuum transducer I suspect.

 

[Uncle Benz]

Vacuum transducer I suspect.

There are so many decriptions of the same thing these days... MAF, MAS etc. My favorite from a parts supplier when trying to order an ISCV for a Ford Fiesta with OHV HCS engine was 'DCTM mate'. When asked what he meant, he explained 'don't come 'till Monday'.

My point is, I think we mean the same thing - black, 2 pipes, one small filter, one electrical connector with 2 wires. Can't find a picture, sadly...

 

[hampshire jock]

Well thanks to all who help me here. it was a 60quid boost pressure sensor which had failed. replaced yesterday and i now have much more responsive ml 270 !

thanks for all the help

 

[ml270]

i have a ML 270 cdi 2003 49 k - had loss of power - limp mode - so took to local indy MB garage. everything pointed to MAF but wasnt. has a short code diagnostic of P1470 ??? this points to the turbo boost pressure being too high or too low. the turbo whine is definelty intermittant and local indy MB says it will need a full diag scan to be sure of the problem.

Has anyone heard of the is problem before - is it the turbo - if so how much will one of those cost ???? or could it be problems with ECU or software ?

will a full scan uncover the issue - any other suggections ?

thanks i advance

v worried ML owner

im new here so first off i would like to say hi to you all
i have a 2000 ml 270 cdi
it loses power very intermitantly and will not rev above 3000rpm(seems like get home safe mode).if i turn ignition off and restart engine it will be fine for a while .i have read as many threads as i can find on this and they all seem to point to the maf. so i changed this and the problem still persists. i changed it again for a pierburgh one that was fitted originally by merc.however this problem still persists.im sure some one out there must have the answer please please help it drivin me crazy
br
ml270
ps i have also had it on diagnostics but it shows nothing to be at fault
was this the same problem
please reply
br
ml270

 

[ml270]

hi all
sorry it took me so long to get back it was me who started this thread...i tried every thing every one said,maf,gearbox oil,manifold,egr,splitpipe to turbo and the last thing i tried as it was the most expensive was the cat.i was a little dubious about doin this as it does cost.i found out from my local mot station that a cat on a diesel does not come under current mot it is all emmisions.i was still dubious about spending the money.so my local garage cut the side of the box took out the cat and welded it back up.......the result???????perfection
thank you everyone for your help and hope this may help others
br
ml270

 

[Ogumar]

hello everyone
i own an ML270 cdi with 53000 on the clock and have a similar problem to that posted by ml270 can someone with the rev not going beyond 3000rpm
please help

 

[Chris1288]

Sounds like a faulty boost control solenoid valve to me...

Hi I seem to have the same problem on my 2002 ml270. Loss of power, I've been told its a vacuum pressure boost valve. Could it be just as simple as this?

 

[Wighty]

Hi I seem to have the same problem on my 2002 ml270. Loss of power, I've been told its a vacuum pressure boost valve. Could it be just as simple as this?

I suppose it depends who told you , and how they arrived at this assessment ?

 

[Chris1288]

I suppose it depends who told you , and how they arrived at this assessment ?

They said it was plugged I to diagnostic computer and fault code points to this. They have ordered me the part and said wil fit it and will solve the issue.??