C220 Cdi Manual (w203) 53 Reg NOT REVVING

[faisalamir50]

hi all once again, the mechanic has got the conrod in and the banging and smoking has gone away even though it is still a bit smelly from the exhaust, but what it is doing now is it wont let it rev over 3000 and to get to 3000 it takes a while, i assume it is one of the following, MAF, CAT CON, VACCUM PIPE, TRANSMISSION CONTROL MODULE, OR EVEN THE 02 SENSOR, below is the diagnostics report P0443 and P0455 will have now been cleared as the conrod is now repaired and no smoke is present

P0125 : Insufficient Coolant Temperature for Closed Loop Fuel Control
P0196 : Engine Oil Temperature Sensor Range/Performance
P0234 : Turbo/ Super Charger Overboost Condition
P0299 : Turbo/ Super Charger Underboost
P0443 : Evaporative Emission Control System Purge Control Valve Circuit
P0455 : Evaporative Emission Control System Leak Detected (Large leak)
P0736 : Reverse incorrect gear ratio
P1143 : Air Assist Control Valve Range/Performance
U0001 : High Speed CAN Communication Bus
U0101 : Lost Communication with TCM
U0106 : Lost Communication with Glow Plug Control Module

 

[horgantrevor]

it sound like its in limp home mode but........ one i had a mitsubishi L200 for work got some work done on engine the guy fixed it but forgot to put the vaccum pipes back on right it took many long weeks of driving before we found the right order once found it worked perfect ...
i would have a look the L200 would take forever to rev to 3000 revs and when it did it would stop their....... it has to be this im almost sure i hope the indy marked them

good luck

trev

 

[psmart]

Sounds very much like you have no Turbo control, ie. when I diconnected the Boost Pressure Control Valve it would get to 3000, but slowly. Having a Boost Pressure Over Pressure AND an Under Pressure could indicate that the Boost
Pressure Sensor on the right hand top side of the intercooler is faulty, or the Boost Pressure Control Valve (left side, front, looks like a small condensor with two pipes going into the top, a old style petrol filter dangling below it
with 2 wires) is not regulating the Turbo correctly (thus forcing a Turbo shutdown by the ECU) or the vacuum circuit has a leak in it (used to control the Turbo via the BPCVT) or an air leak in the Intercooler. Unless a mechanic has seen this exact situation before, its investigation time unfortunately.

This link, I describe roughly how the system works from my own investigations: http://forums.mercedesclub.org.uk/showthread.php?t=28754

I would initially go about proving the area of the fault, so you can prove if the fault lies in the air induction system by simply disconnecting the pipe between the BPCVT and the Turbo (put a plastic cover over the BPCVT inlet from where you pulled off the pipe). If the car drives the same, then the fault lies in the Turbo control system. If this is the case, perform a manual inspection of the pipes (and run the engine and listen for leaks, especially round the intercooler. If non of this helps, then its part replacement time, here a 2nd vehicle aids tremendously (I used our C220cdi as a donor for the ML270 as most parts were identical).

There is no easy way of determining which part is faulty without specialist test rigs, hence the deduction and swap principle (often used by most dealerships at your expense).

 

[horgantrevor]

Ya I Once New A Guy Who Rented A Car To See If He Could See Were He Had Gone Wrong Now He Found The Fault On His Car Easy Comparing Like For Like

 

[psmart]

Ya I Once New A Guy Who Rented A Car To See If He Could See Were He Had Gone Wrong Now He Found The Fault On His Car Easy Comparing Like For Like

There is a big difference to blind part swapping and deducing the fault. You might hit upon the fault by blind part swapping, or you may just damage the donor part and end up with two bad cars, more especially where electrics are concerned. Simple resistance and voltage tests between two parts will indicate wether a part's electrics are shorted and also wether the control circuit (ECU etc) is faulty. Doing this before swapping the part could save you from buying 2 new ones!

 

[faisalamir50]

hi, and thanks for your fast reply, i know you think it is in limp mode but the limp mode light in the car is not on, so what could that mean, plz get back to me

 

[horgantrevor]

There is a big difference to blind part swapping and deducing the fault. You might hit upon the fault by blind part swapping, or you may just damage the donor part and end up with two bad cars, more especially where electrics are concerned. Simple resistance and voltage tests between two parts will indicate wether a part's electrics are shorted and also wether the control circuit (ECU etc) is faulty. Doing this before swapping the part could save you from buying 2 new ones!

the doner car was to only be used to check the vaccum hoses no parts to be swapped .

the light is not on for limp mode . at this stage is all the engine back together and if so the prob is no reving when pressing the pedal .....

will the engine tick over ok on its own dose it sound ok

has the smoke gone

has the nocking gone

if so a sensor for ECU may be at fault

i thing you need to get the car checked again on a computer . as this may be the fastest way to fix prob

good luck

trev

 

[faisalamir50]

Thanks

hi mate thanks for your reply,

the car at the moment gives only some smoke after a while i would say every 10 - 15 minutes a small amount gets blown out, but as the fuel injector was leaking in cylinder 4 the smoke still remains, the fuel injector has now been replaced

Second of all the engine sounds like a normal diesel engine with a bit of knocking, but when warms up it quitens down, while revving it it increases the knocking noise, it is like knocking similar to this one
http://www.youtube.com/watch?v=Hk5A6MFla4Y

last of all i plugged it into my computer to read the sensor and the MAF is at 8.66 g/s when the MAF is connected and 8.66 g/s when i disconnect it and doesnt change the figure while engine is started, and some one told me it should be alot higher than that, also i cleared the codes as the conrod was replaced, how do i retrieve them so that i can show the car to the mechanic

can you please get back to me thanks faisal

 

[psmart]

I checked with my ML270, when the MAF is unplugged, the air mass is 8.66 g/ms, but when the MAF is plugged in, and the engine has just started, it hovers around 7.9 g/ms for about a minute, then changes to 14g/ms. If I unplug the turbo vacuum, then start the car, the MAF reading is 14g/ms, so looks like at start, the ECU reduces the airflow.

Driving around, the airflow rises to 60++g/ms.

Sounds like your MAF is dud! When I had my MAF unplugged, the car drove, but didnt rev so easily and the engine torque was much higher than when the MAF was connected for a given speed/gear. It also seemed to be limited to around 2500 rpm, but this was more due to the Turbo not being actuated as the turbo actuation arm hardly moved.

 

[faisalamir50]

Hi thanks for your reply PSMART

hi thanks for your reply mate, yeah i think my cars MAF is mesed up because when i check the MAF unplugged it is on 8.66 and when i plug it back in it for some reason it starts at like 3 -4 and then goes up and max at 8.66, but the engine noise stays the same weather if it is plugged or unplugged, i even drove it in first gear around my garden and it sticked to 8.66, thanks for reply mate it is very appreciated

AND ALSO FOR EVERYONE ELSE THE ABOVE REPORT IS WRONG, I HAVE ONLY USED THE DIAG FOR A FEW MONTHS AND IT WAS EXAMPLES

 

[faisalamir50]

Heyy

i replaced the MAF and its fixed the problem and the Revvs in park go to about 3500 and when i drive theygo over now the only problem is the noise, i have some minor knocking / vibration noises when i give the car some gas, a mechanic over the road, checked the car and said it is the nearside engine mount,