W211 E320CDI OM642 Turbo Actuator Replaced - still sometimes in limp mode. Is it EGR?

[Stocho]

Hi,

On 2006 E320CDI facelift Turbo Actuator was repaired about 5 years ago by a reputable repair. Prior to repair there was a lot of kangarooing and limp mode.

About six months ago car started entering limp mode again but with no kangarooing at all. It would only enter limp mode about 15% of the time and only from start - never mid-journey. Just switching ignition off and on would always "fix" the problem. There was the usual "Wastegate solenoid Range/Performance" error code. So the diagnosis was made that it is Turbo Actuator that is at fault again.

Turbo actuator was replaced with a brand new Chinese copy. The car now enters limp mode about 10% of the time - but that now can happen not immediately after start. So in a way the problem is worse. Code reader does not show the usual actuator error code - "Wastegate solenoid Range/Performance". The OBDII codes are:
P0404 Exhaust Gas Recirculation Control Circuit Range / Performance
P0132 O2 Sensor Circuit High Voltage Bank 1 Senso1
P2A00 O2 Sensor Circuit Range/Performance Bank 1 Sensor 1.

In case it might be relevant about at the same time that Turbo Actuator was replaced IC went dead and currently car is with IC cluster from another car and iCarSoft shows error codes related to that, (Could that be masking true error codes?) (W211 facelift Instrument Cluster dead - can it be replaced without recoding? | Electronics and Audio)

Currently awaiting delivery of Forte Deiseal Turbo Cleaner / Deiseal Specialist Injector Cleaner in case these help...

Would be grateful for advice on what is actually wrong with the car and how to fix it? Is is still the actuator fault which does not get reported correctly (perhaps as the new actuator is a Chinese copy or because of IC issues)? Is it EGR issue and if so is it caused by the Chinese actuator not performing as it should and throwing up problems further down the line? Or is it yet another unlucky coincidence and is a new problem?

 

[Stocho]

After lots of testing and driving I am now able to reproduce the intermittent fault without a fail.

It looks like it goes into the limp mode only when the car is stationary (not necessarily just started, includes stopping after driving). Furthermore I am able to reproduce the fault as follows.
With car in parked gear and with all DTC errors cleared:
1. Bring revs just under 3000, the iCarsoft i980 tool shows EGR valve is at 95% when revs are between 2500-3000. Keep in that range for a few seconds.
2. Increase revs to over 3000, at this stage EGR valve shows as 5% open.
3. Go back to 1. i.e. reduce revs to under 3000 and observe EGR open position go back to 95%

After cycling like that for 3-5 cycles, at one point at step 3 even when revs go back to just under 3000 EGR position stays at 5%. This means that the fault has been triggered and the car is in limp mode. The new codes that appear at this point are:
OBDII: P0404 Exhaust Gas Recirculation Control Circuit Range / Performance
i980 Diagnostic CDI 4: 2511-000 which internet search revealed also relates to EGR.

With such a behaviour (able to drive at high speed, flooring the car with excellent response and no issues for miles, even when trying to trigger it as above requiring 3-5 cycles) could the issue still be sticky EGR Valve? Is it more likely to be back pressure sensor? I tried removing EGR Valve but using my hands and revving the engine to the maximum failed to dislodge it - so to remove it would involve ruining it even thought it might not be faulty. Is back pressure sensor safe to remove for cleaning or is removal process also could lead to further issues (like with glow plugs that can just snap)? Any other advice?

 

[W1ghty]

After lots of testing and driving I am now able to reproduce the intermittent fault without a fail.

It looks like it goes into the limp mode only when the car is stationary (not necessarily just started, includes stopping after driving). Furthermore I am able to reproduce the fault as follows.
With car in parked gear and with all DTC errors cleared:
1. Bring revs just under 3000, the iCarsoft i980 tool shows EGR valve is at 95% when revs are between 2500-3000. Keep in that range for a few seconds.
2. Increase revs to over 3000, at this stage EGR valve shows as 5% open.
3. Go back to 1. i.e. reduce revs to under 3000 and observe EGR open position go back to 95%

After cycling like that for 3-5 cycles, at one point at step 3 even when revs go back to just under 3000 EGR position stays at 5%. This means that the fault has been triggered and the car is in limp mode. The new codes that appear at this point are:
OBDII: P0404 Exhaust Gas Recirculation Control Circuit Range / Performance
i980 Diagnostic CDI 4: 2511-000 which internet search revealed also relates to EGR.

With such a behaviour (able to drive at high speed, flooring the car with excellent response and no issues for miles, even when trying to trigger it as above requiring 3-5 cycles) could the issue still be sticky EGR Valve? Is it more likely to be back pressure sensor? I tried removing EGR Valve but using my hands and revving the engine to the maximum failed to dislodge it - so to remove it would involve ruining it even thought it might not be faulty. Is back pressure sensor safe to remove for cleaning or is removal process also could lead to further issues (like with glow plugs that can just snap)? Any other advice?

What a saga buddy !
I’ve got the same car which I’ve had for 120k miles and 12+ years .
My basic understanding of the car is that the following things are all on the same fuse which means that sometimes it’s hard to pin down exactly where the fault is coming from .
They are all linked by fuse F44 (15amp) that is in the engine bay fuse box by the brake fluid reservoir.
I would change this fuse anyway to start with .
The exhaust back pressure is any easy removal with a 24mm deep socket , watch the silver washer below it ! Spray clean the underside hole that gunges up with black muck….carb cleaner .
If it is the original ebps they are £66 from MB Newcastle eBay .
The egr will come out , spray some penetrating fluid into the gap, then gently knock a chisel into the gap to try and very gently create a tiny bit of movement , then more penetrating fluid . With this slight gap , then try and use a slightly thicker screwdriver to move it further . You could then try and knock the egr valve side to side with a piece of wood and a hammer . Gently is the key , if it really doesn’t move then leave it for someone else rather than crack something .
Assuming you get the egr valve out then it can be dismantled and cleaned . I’ll have a hunt for the thread by @unclebuck when he did it .
The inlet port motor sits below the orange turbo seal on the front of the batwing MAF , this leaks oil from the seal which damages the motor and affects the swirl flaps . Google “om642 inlet motor resistor fix” which involves a 4.7k ohm resistor fitted into the middle two terminals of the inlet port motor to trick it into thinking the swirl flaps are working….cost £1.
The turbo actuator is also on this fuse as well .

 

[W1ghty]

Thread 'Egr valve clean up'

Apr 29, 2021

Took the egr valve off yesterday, no issues or codes just some preventative maintanance.

the soot coating was a little thick and sticky, so i hit it with some cleaner and took my time going over it several times. Picking up a new seal washer for it from merc tomorrow with a few other things, another job ticked off the list.

• unclebuck
• Replies: 21
• Forum: Engine

• 

 

[W1ghty]

My suggestions are what I would try and actually do every couple of years as preventative maintenance on my car .
They don’t cost anything apart from a couple of hours of time .
Failing all that working it might be MB specialist time , unless you think you can pin down the part that you think is playing up .
The ebps you may as well replace anyway if cleaning doesn’t work , they are cheap enough and don’t last forever anyway .

 

[Stocho]

Thread 'Egr valve clean up'

Apr 29, 2021

Took the egr valve off yesterday, no issues or codes just some preventative maintanance.

the soot coating was a little thick and sticky, so i hit it with some cleaner and took my time going over it several times. Picking up a new seal washer for it from merc tomorrow with a few other things, another job ticked off the list.

• unclebuck
• Replies: 21
• Forum: Engine

• 

Thanks for so much advice, will be returning to it as I keep trying to resolve the problem.

There are actually two W211 facelift E320CDI in the family one 56 plate (that has this problem) and the other 57 (that does not have such problems). So I thought why not swap EGR Valves / back pressure sensors and see whether I still have problems. That I did, and I still had problems - they were exactly the same, perhaps slightly better, as, perhaps, I had on average to do more cycles from post number 2 to induce limp mode (but could well be just statistical fluctuations).

So that was disappointing as if swapping EGRVs/Sensors had fully resolved the problem then diagnosis would be essentially complete.

In terms of removing EGR Valve I had to use a chisel as in

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

. However I used a sharper chisel (and quite wide) and all it needed on both cars is 2-3 moderate knocks.

Both EGR Valves / back pressure had some carbon deposits but not the sort of extreme cloggage seen on some youtube videos.

So this would seem to indicate the issue is not with EGR Valve ... but then I noticed it does sometimes tick when fully opened (another post below on this).

 

[Stocho]

Today tried to clean carbon from the EGR Valve that was originally in the faulty car. I really could not see how that little carbon could result in it sticking - and it was nothing compared to some youtube videos where EGR Valves were really full of oily soot (in mine it is just soot - no sign of oil).

The valve is normally in the open position and took quite a while to figure out how to open it - requires quite a bit of force. And I noticed that sometimes it sticks when moved to fully open position. This has nothing to do with the soot in the Valve, it appears what is causing it to sticks is friction in the gear mechanism. So I removed the black plastic cover to access the gear mechanism.

The first picture below is the valve stuck in the open position. I circled in red the area of friction.

The second picture below is the valve in the closed position. Again I circled in red colour the area where I believe there is sometimes friction (when the plunger slightly twists).







Now, I am hoping that perhaps the fault with the EGR Valve after all. Perhaps both of them are sticky and the other car's ECU is soehow more robust to this problem and hence never had the problem in the other car.

So I will be applying lubricant to the area circled in red on the pictures above.

Is the lubricant below (chosen as rated to 1500C ) ok for this job? Could I try to also lubricate the stem or would this lubricant harm the engine if small bits of it end up in pistons?

 

[W1ghty]

Thanks for so much advice, will be returning to it as I keep trying to resolve the problem.

There are actually two W211 facelift E320CDI in the family one 56 plate (that has this problem) and the other 57 (that does not have such problems). So I thought why not swap EGR Valves / back pressure sensors and see whether I still have problems. That I did, and I still had problems - they were exactly the same, perhaps slightly better, as, perhaps, I had on average to do more cycles from post number 2 to induce limp mode (but could well be just statistical fluctuations).

So that was disappointing as if swapping EGRVs/Sensors had fully resolved the problem then diagnosis would be essentially complete.

In terms of removing EGR Valve I had to use a chisel as in

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

. However I used a sharper chisel (and quite wide) and all it needed on both cars is 2-3 moderate knocks.

Both EGR Valves / back pressure had some carbon deposits but not the sort of extreme cloggage seen on some youtube videos.

So this would seem to indicate the issue is not with EGR Valve ... but then I noticed it does sometimes tick when fully opened (another post below on this).

That’s a shame .
So we can rule out ebps and egr then .
You can still try the resistor in the swirl flap motor as a cheap test ?
Just thinking aloud , I wonder if blocked egr pipe work would also flag as an issue , even thought the valve itself is ok ?

That’s pretty much me out of further advice now based on my experience.

 

[W1ghty]

Today tried to clean carbon from the EGR Valve that was originally in the faulty car. I really could not see how that little carbon could result in it sticking - and it was nothing compared to some youtube videos where EGR Valves were really full of oily soot (in mine it is just soot - no sign of oil).

The valve is normally in the open position and took quite a while to figure out how to open it - requires quite a bit of force. And I noticed that sometimes it sticks when moved to fully open position. This has nothing to do with the soot in the Valve, it appears what is causing it to sticks is friction in the gear mechanism. So I removed the black plastic cover to access the gear mechanism.

The first picture below is the valve stuck in the open position. I circled in red the area of friction.

The second picture below is the valve in the closed position. Again I circled in red colour the area where I believe there is sometimes friction (when the plunger slightly twists).

View attachment 163932

View attachment 163933



Now, I am hoping that perhaps the fault with the EGR Valve after all. Perhaps both of them are sticky and the other car's ECU is soehow more robust to this problem and hence never had the problem in the other car.

So I will be applying lubricant to the area circled in red on the pictures above.

Is the lubricant below (chosen as rated to 1500C ) ok for this job? Could I try to also lubricate the stem or would this lubricant harm the engine if small bits of it end up in pistons?

View attachment 163934

That grease temp will be perfect , the whole engine bay would be on fire at half that temperature!

 

[Stocho]

So tried good car's EGR Valve and back pressure sensor is faulty car - still able to induce limp mode with EGR error code.

Tried faulty car's EGR Valve and back pressure sensor in good car - no faults.

Put back faulty's car EGR Valve and back pressure sensor back into faulty car - still being able to induce limp mode with EGR error code. In fact problem became even worse today coming up quite quickly even during normal driving.

Next step was to swap Turbo Actuator as my problems started shortly after I replaced Turbo Actuator in the faulty car. I bought a copy rather than a refurb - shame on Mercedes for refusing to supply actuators as standalone units!

The actuator in the good car is G277 while in the faulty car is G219. I still installed good car's actuator into faulty car. After that I was not able to induce limp mode however hard I tried! So the fault is with a copy actuator bought from ebay!

I do wonder how does ECU know what error message to trigger and why it failed to identify the culprit in this instance, incorrectly blaming EGR? If something like CAN bus (where a rogue device could hijack the whole network) is used by ECU to communicate with the turbo actuator, EGRV, etc then could copy actuator be deliberately designed to ensure no Turbo related messages are raised so that the actuator is not identified as the device at fault and returned?

So, the "EGR problem" was caused by copy actuator from Ebay. The same day I installed that copy actuator my IC also went dead (W211 facelift Instrument Cluster dead - can it be replaced without recoding? | Electronics and Audio) , now wondering whether that is also related to the copy actuator?
Pictures of the copy actuator that caused these issues:

 

[Stocho]

Now tempted to place this culprit copy actuator in the other ( "good") cars and see what happens. My IC did go bad when I installed it into the "faulty" car but I suppose that could be a coincidence? Could it really cause lasting damage that will persist after its removal?

 

[Smart320]

Seems pointless, why even take the risk . Just get a genuine MB unit and then you will have 2 cars that run correctly rather than 2 that won’t

 

[W1ghty]

So tried good car's EGR Valve and back pressure sensor is faulty car - still able to induce limp mode with EGR error code.

Tried faulty car's EGR Valve and back pressure sensor in good car - no faults.

Put back faulty's car EGR Valve and back pressure sensor back into faulty car - still being able to induce limp mode with EGR error code. In fact problem became even worse today coming up quite quickly even during normal driving.

Next step was to swap Turbo Actuator as my problems started shortly after I replaced Turbo Actuator in the faulty car. I bought a copy rather than a refurb - shame on Mercedes for refusing to supply actuators as standalone units!

The actuator in the good car is G277 while in the faulty car is G219. I still installed good car's actuator into faulty car. After that I was not able to induce limp mode however hard I tried! So the fault is with a copy actuator bought from ebay!

I do wonder how does ECU know what error message to trigger and why it failed to identify the culprit in this instance, incorrectly blaming EGR? If something like CAN bus (where a rogue device could hijack the whole network) is used by ECU to communicate with the turbo actuator, EGRV, etc then could copy actuator be deliberately designed to ensure no Turbo related messages are raised so that the actuator is not identified as the device at fault and returned?

So, the "EGR problem" was caused by copy actuator from Ebay. The same day I installed that copy actuator my IC also went dead (W211 facelift Instrument Cluster dead - can it be replaced without recoding? | Electronics and Audio) , now wondering whether that is also related to the copy actuator?
Pictures of the copy actuator that caused these issues:

View attachment 163984

View attachment 163985

View attachment 163986

View attachment 163987

Like I said in a post above . The actuator,inlet motor,ebps,egr are all linked so a fault in 1 can show up as another .

 

[ALFAitalia]

Seems pointless, why even take the risk . Just get a genuine MB unit and then you will have 2 cars that run correctly rather than 2 that won’t

MB wont sell them without the whole turbo!!!

 

[BlackC55]

The replacement actuators are very hit and miss. More miss than hit. We gave up in fitting them. I found out why most dont work or dont work for long. They are matched to the turbo itself during production. Buy a complete decent quality turbo by Garrett. They work and will save you ball ache.