2003 w203 - c 200 cdi turbo prob?

[jobela]

Hello, all and a happy new year.

Hopefully someone will be able to help me out.

The car started to go into limp mode, not passing 3000 rpm, lacking torque and no autogear box switching, unless I forced it. The components are Bosch. Someone told it was the variable actuator on the turbo and I would have to replace it, a Garret 1852. I wanted to see other things, since I'm told these turbos are life lasting, so I changed the maf. Imediatly it started passing the 3000 rpm, but the CEL just turned off the next day. So far so good, changed the air filter for a K&N, no oil in the air filter so it wouldn't damage the sensor element. This lasted for 2 to 3 weeks, then it came back.

Do you think the maf needs replacing, and then I can get a new one, since this is under warranty? Or is it because of the K&N filter? If so, should I go back to stock or can I change it to GREEN? And how do I reset the CEL without STAR? Should I disconnect the battery for half an hour?

Also, on a X431 tester, the fault codes are: 2514-Check ventilation heater element, component R39/1; 2359-Check charge pressure control (auxiliary pressure too low); 0105-check charge pressure sensor B5/1 (Voltage too high).

Any help appreciated!

 

[tuikku]

.
Measure the real boost pressure.

Is your charger electronic- or vacuum- controlled.

Maybe the program sees the pressure wrong somehow.
There are might be too much boost pressure according turbo vanes position.
Sensor data incongruity.

You find it out by measuring the real pressure, when engine runs "normally".

 

[jobela]

.
Measure the real boost pressure.

Is your charger electronic- or vacuum- controlled.

Maybe the program sees the pressure wrong somehow.
There are might be too much boost pressure according turbo vanes position.
Sensor data incongruity.

You find it out by measuring the real pressure, when engine runs "normally".

Thanks for the answer

Electronic actuator on the turbo.

To measure the real pressure, I'd have to buy and know how to use some tools...

 

[tuikku]

.
Here is MAP-sensor (manifold_air _pressure)
It is easy to "steal" the pressure here.
Every pressure- gauge is ok.
Real or right max boost pressure is something between 1,2-1,3 bar.
(1,25bar in program)

 

[jobela]

This photo is for which engine? Mine is a 646962! Because the signal tube for the MAP I have in mine, doesn't have a "T" piece, it just goes straight to the mixing chamber...?

 

[tuikku]

This photo is for which engine? Mine is a 646962! Because the signal tube for the MAP I have in mine, doesn't have a "T" piece, it just goes straight to the mixing chamber...?

...That tube comes in to my boost gauge.

 

[jobela]

Thank you all for your contribution. Turned out to be the MAP sensor. Nevertheless, I gave it a good cleaning on the EGR valve with electronic circuit board cleaner (was handy).

Best Regards

 

[valveman]

loss of power E320cdi V6

I had a similar problem with my e class. Under hard acceleration the car would go into limp mode i connected my scanner and it came up with (2359 Check system charge pressure boost pressure t low) I sent off the turbo actuator for repair and when re fitted it was just the same, So next I stripped down the turbo system and found that the inter cooler had split. I am off to get a new one tomorrow and finger crossed that should sort it.

 

[haider254]

Thought I'd post here for people like myself dealing with this issue. I've had this issue off and on for 2 years now. The car was driveable but with fast acceleration, when towing and at motorway speeds, the "limp mode" would be initiated. It even got to the point where I kept an ODB plugged in and would clear the fault codes whilst driving to get the car back to normal.

When this first happened I had the car diagnosed by a local garage. They're smart boys but didn't have a Star tester, they did, however, find a leak in the intercooler and one of the boost hoses. I decided to replace all of them and hoped that would sort it out. Well, it didn't...

I took it to a merc specialist with a STAR. We started diagnosing and noticed that boost pressure wasn't in the parameters in any rev range (attached image is at idle). We went through all of the boost hoses, checked out the EGR, tested the turbo out to try to rule out any issues with the turbo or the electronics unit and made sure the exhaust system was intact (making back pressure). All seemed well and I was told to replace the MAP sensor. I went to the local Merc parts place and got a 3 bar Bosch MAP (0 261 230 193) to replace the MAP that was installed and assumed to be broken (A0041538428).

The issue wasn't solved. I decided to just monitor the issue and wait for the fault to present itself in a more apparent way. The car is at this point my wife's commuter and she does mainly city driving and doesn't drive as aggressively as I do so the limp mode doesn't really affect her day to day.

Well, boy did the fault present itself. The turbo started whining and failed magnificently by starting burn oil. Most people would be pissed about this but I was ecstatic, I would finally replace the turbo and sort this issue out. I had always suspected the turbo even though the turbo and electronics unit passed the Star diagnostic. Well, I put a turbo on order and replaced it. 2 years ago I wouldn't have dreamt of replacing it myself but I decided to do it anyway and managed it nicely. I thought I would finally be rid of this issue.

I was wrong. It kept doing it, the turbo replacement made no difference...

Well a few days ago I went to another garage with a STAR, they're a tuning place so I thought I'd give them a chance to take a look at it. That was a bit of a mistake. The bloke started saying that the turbo's electronics unit is clearly broken because the actuator is constantly on, even at idle. I thought that surely it's supposed to be that way if the boost pressure is below the set parameters for that rev range, the turbo would actively try to boost the pressure. After a bit of back and forth, we once again landed on the MAP being the issue. He said to just go to the dealership and get an original MAP. He said you should always use original sensors on mercs as even quality replacements by other manufacturers can cause issue.

I decided to take another look at the engine and I noticed an oil stain at the root of the MAP tube on the manifold. To me it's a clear sign of a leak in the tube. It was also installed with cable ties instead of metal hose clamps. I decided to order a new one with proper hose clamps. A few days later the parts arrived and I swapped them out. The old one was all floppy but I couldn't find a clear leak. When comparing with the new one though, the rubber was really loose and felt thin. I think it just didn't seal properly against the manifold with the cable tie setup.

Well, it's now replaced and the fault hasn't shown up once yet. The car is also much more responsive and those judders, especially at gear changes when cold seem to be resolved. I was certain those were just signs of the old girl showing her age but it looks as though it was just this issue causing this. I'm not completely convinced yet because sometimes the issue can take a while present itself, but I have a good feeling this time. I checked out the actuator at idle and it goes to the down position, whereas before, it was in the upper position even at idle. I'm probably going to go hook it up to a star again to check out the values.

What did I learn:
- I should have done a proper pressure test on the system from the get-go. I think all of the boost hoses had reached the end of their life and were due for a replacement. Finland is rough on rubber parts.
- I like to avoid the dealership like the plague, but for fault diagnostics that may have been a good option. They see these issues on a regular basis and may have been able to suggest this ages ago. I do fear that they would have just looked at their star and would have wanted to replace everything imaginable, but I've basically already done that over the last few years.
- Buy original merc rubber parts, I've had to replace one of the boost hoses twice, it was torn to shreds in one year of use.
- Don't dismiss a part because it feels insignificant. At the end of the day, had I actually gone over the whole intake system looking for leaks, I should have maybe even started at the MAP tube considering this is where the reading is taken from...

Parts replaced in chronological order:
- Intercooler and left-hand boost hose (150 e)
- All boost hoses (100 e)
- Turbo seal (The orange silicone one) (10 e)
- MAP Sensor (55 e)
- Turbocharger (rebuilt, 450 e with the installation kit)
- MAP tube + hose clamps (10 euros)

Overall I've spent around 200 euros diagnosing the fault at the 3 garages.