Sprinter 311 2.2cdi, excess regen + white smoke + oil level rising

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tcourtneyvincent

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Sprinter
Hi there guys

I am beating me head against a wall here. Have been to the so called "merc specialists", local guys and spoken to all between including scrolling all the forums on the Internet and still don't have a solution.

Engine runs great 95% of the time. When its in its regeneration of the DPF state however it can pump out white smoke from over fueling (only when regening tho! So surely not injectors?)

Its not loosing any coolant

Diesel is getting into the oil and the level is rising at a rate of aprox 1l every 3000 miles altho this amount seems to vary, I then replace the oil so as not to damage the bottom end bearing.

I have done a compression test which is coming back as 24, 24, 22, 23 which i'm told is very good? Can someone confirm this?

It can stay in regen phase for sometimes up to 50 odd miles and over an hour of driving before seeming to give up and reverting back to driving perfect again for the next 300 miles. If these 50 miles are made up of shorted trips it will go straight back into regen on startup even when the engines cold...i thought it only did a regen when the engine was hot!?

There are no engine code, EML or anything... I got so fed up with "specialists" charging silly money for a scan and telling me its fine and must be injectors that i bought an Icarsoft v3 and it picked up an "over voltage", "under voltage" and "signal implausible" of the DPF pressure differential sensor. I have replaced this with a good boshe unit and no fault code since but I still have the same problems.

Am I correct in think injectors cant be the problem as if they were leaking I would have the white smoke at tick over all the time, not just when in regen.

A weird thing I noticed the other day. Looking at the live data mid reg the soot content was sat at -0.58g/l, yet despite these negative figures it still goes into reg again on start up....

Thanks in advance :)
 
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Is water leaking into the exhaust/engine? Do these have a water to air intercooler?

The rising oil level would worry me more than the smoke. Does the oil smell of diesel or any water settling?
 
Is water leaking into the exhaust/engine? Do these have a water to air intercooler?

The rising oil level would worry me more than the smoke. Does the oil smell of diesel or any water settling?
Ah yes, just to be clear, its 100% fuel getting into the oil, i can smell it. And the white smoke from the exhaust is unburnt fuel from the regen process.

No im not loosing ant coolent

I will edit to original post to inc this
 
Has the DPF been changed in either your ownership or previous owners ? When you fit a new DPF you have to tell the ECU its a new one and do a recalibration of soot/ash levels.
 
Has the DPF been changed in either your ownership or previous owners ? When you fit a new DPF you have to tell the ECU its a new one and do a recalibration of soot/ash levels.
I havent changed it and theres no service history so not sure. To be honest I was considering just resetting it and telling it its a new DPF just to see what happens.
Its an old royal mail van with 150k on the clock. So likely the DPF has gotten blocked and been replaced in the past?
 
I would consider getting the injectors tested to rule them out? Maybe they're leaking/stuck open and the increased temps in regen cause the smoke.

How are you telling when it's in regen and for how long?
 
Exhaust temp is more important than engine temp for a regen. Mine can go back into regen at 40 C.

Is it possible the DPF is blocked with ash, I guess differential pressure would show that?

Surely diesel into the oil must be by passing the rings.

If it's of any help, I had white smoke / too regular regens on a 642 engine. The oil level wasn't rising though. New injectors made no difference. I do believe the sump was being pressurised.
 
I would consider getting the injectors tested to rule them out? Maybe they're leaking/stuck open and the increased temps in regen cause the smoke.

How are you telling when it's in regen and for how long?
I guess im not 100% sure but the sound of the engine totally changes, it sounds throaty, the throttle response becomes slow and you can hear the injectors firing differently, then the smoke occasionally starts.

As for the injectors, i could do. Up in till now its been too big of an expense which seemed unlikely just for the sake of ruling it out
 
Exhaust temp is more important than engine temp for a regen. Mine can go back into regen at 40 C.

Is it possible the DPF is blocked with ash, I guess differential pressure would show that?

Surely diesel into the oil must be by passing the rings.

If it's of any help, I had white smoke / too regular regens on a 642 engine. The oil level wasn't rising though. New injectors made no difference. I do believe the sump was being pressurised.
Do you know what the temps should be? Im just looking back at a video I took of the live data while it was in what I thought was reg cycle. Mine is showing 600 degrees C at the Cat, and 485 degreens C at the DPF. Does this sound about right? Should the DPF be hotter or cooler than the Cat? I know its after but the Cat does some secondary burn progress right and 485 sounds like it could be too cool for a regen?
 
I wouldn't know mines in regen if I didn't see the exhaust temp shoot up on Torque.
 
I wouldn't know mines in regen if I didn't see the exhaust temp shoot up on Torque.
okay thats interesting. Surely hearing the injectors firing differently is a given tho as they have to give an extra injection on the exhaust stroke. Wait what vehicle / year do you have? You vehicle may have the separate injector pre DPF instead
 
Normal running the cat is hotter than the DPF.. During regen the DPF temp overtakes the cat.

This one only monitors DPF temp.

Normally my DPF will run at 150 - 450 C (can be higher, but depends on engine load)

During regen that rises above 500 easily, it can pass 700. I've set Torque DPF temp to flash above 525. Depending on journey style I expect regens between 460 - 580 miles. It regens for between 6 - 10 miles.
 
okay thats interesting. Surely hearing the injectors firing differently is a given tho as they have to give an extra injection on the exhaust stroke. Wait what vehicle / year do you have? You vehicle may have the separate injector pre DPF instead
OM 651, pre ad blue. 2014 Viano.
Extra injection on the exhaust stroke causes regen.
 
Normal running the cat is hotter than the DPF.. During regen the DPF temp overtakes the cat.

This one only monitors DPF temp.

Normally my DPF will run at 150 - 450 C (can be higher, but depends on engine load)

During regen that rises above 500 easily, it can pass 700. I've set Torque DPF temp to flash above 525. Depending on journey style I expect regens between 460 - 580 miles. It regens for between 6 - 10 miles.
This is great information thanks. I will collect more data from driving and cross check it with this. If you are not supposed to hear it regening im starting to wonder what mine is doing. Sounds like the timing changes in as much as the injectors become all clattery, there is slight detectible drop in power, slow throttle response and that throaty sound you get when you block an airflow or are in limp mode with the waste gate fully open on the older sprinters. Once it decides to stop doing this its then fine for another 300 odd miles and drive super smooth
 
I may be worth checking your exhaust isn't becoming blocked. The cats have been known to disintegrate.
Just a thought that the contents of the cat could be moving, causing increased back pressure. That could cause a regen and loss of power.
 
I may be worth checking your exhaust isn't becoming blocked. The cats have been known to disintegrate.
Just a thought that the contents of the cat could be moving, causing increased back pressure. That could cause a regen and loss of
 
I'm guessing live data of back pressure reading should tell me this? Do you know what the back pressure and differential pressure sensor values should be?
 
On this 651 I would have to do a running check.

On my earlier 642 engine at tickover 48hpa, at revs 122hpa.

But if yours is an intermittent fault then you would expect the reading to be acceptable when running correctly. The readings when in fault might give an indication.

Which engine , age is yours?
 

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