Actros: High Oil Consumption - Troubleshooting

Hi everyone,

I'm having a small issue with my engine.
'Specifically, I have very little power and a lot of smoke below 2000 RPM. Above ~2000 RPM, it performs as expected. I've already looked at Fredi's thread, but it doesn't apply to my situation. I've already checked the mass airflow sensor value. It's OK. I've checked all the vacuum hoses, and the intercooler system must also be airtight .'
VTG adjustment?!? - AGR is deactivated (blocked with a screw in the hose).

Diagnostic software is available.

Thank you for your help (as always ).

Regards,
Arne.

Hi Arne,

Sure, here's the translation:

"Here's a small tip to make answering easier:"
Including the year of construction and engine code in the signature saves time on (avoidable) follow-up questions.

Oh - sorry, I'll change it!

MKB ist AFN Bj. 98. In the Corrado.

Just a small update: The car seems to have lost power. I was just driving on the highway. The top speed is good, but the acceleration felt off, and it was smoking heavily.

Could it be the diesel filter?

Please help!

Hi.

Filters, if they draw any attention at all, do so by not letting enough through.
In your case, it's unlikely that too little diesel would lead to too much soot.

TDIs typically only produce soot if there are leaks in the pressure range (turbocharger to engine) or if the EGR valve is stuck open, or if the engine has been excessively tuned.

Adjusting the load setting is not something I would consider.

Here, too, I can only recommend a measurement run with logging of all data, which you can then present here for discussion.
and of course, check the error memory!

Hi Ulf, and everyone else,

Okay:

Tuning: - Chip in the engine control unit (+30 horsepower).
I've had the chip implanted for 4 weeks. It's always emitted a little bit of smoke, but it's been smoking excessively only for the past 2 days.

Ich habe gestern noch den Dieselfilter und den Luftfilter getauscht. No improvement.

I performed a measurement. The air mass is a maximum of 980 – I believe an optimal value would be around 1100?

The turbocharger boost pressure is also quite normal, but it has been observed that it briefly drops by about 0.4 bar around 3000 RPM, for some reason.


Okay, so I went ahead and removed the two chips, put the original ones back in, and... it's not smoking anymore.

My colleague from the chip department suggested that it might possibly be the mass airflow sensor.

'Stuck open EGR valve - I don't think that's the issue because it's normal without a chip tune!'

I've checked the turbocharger boost hoses (visually) - I didn't find anything. It shouldn't be a problem, since I can still drive at the maximum speed.

I would be very grateful for any further ideas, and right now I'm without a car ('Chip' is likely a nickname for a car) and without my friend 'Russ.'

Arne.

Hi!

It's quite annoying when the error doesn't occur without the chip, because then people are quick to blame the chip prematurely.
You say the boost pressure is "relatively" normal. However, I suspect the boost pressure is actually too low, as the mass airflow sensor also indicates low values. Otherwise, it wouldn't be producing smoke. Nevertheless, the chip is providing "full power," which the original software doesn't. I can imagine a faulty boost pressure control valve that isn't building up the boost pressure sufficiently, which might not be as noticeable within the normal boost pressure range. Also, a slightly stuck-open EGR valve is possible, which might be just within the tolerance range of the "normal" boost pressure.
Your problem is definitely a boost pressure issue, especially since you're experiencing a noticeable pressure loss even at 3,000 RPM.
LMM (Lambda Measuring Module) is not an option; in case of a defect, you'll experience less fuel consumption/exhaust emissions.
"How 'normal' does it drive now without any performance upgrades? What is the performance like according to Ulf's DZR (Dynamic Zero Emission Range)?"

Best regards,
Uwe.

Hi Uwe,


Is that the boost control valve, the one with the white cap?
'Is there a way to clean this or run a diagnostic test, or should I just replace it? (A colleague has a spare one).'

Slightly stuck EGR valve - I'm experiencing this issue right now.
There's nothing blocking the EGR valve, so it's open. I've already checked the hose connected to it and tried to seal it, but there was no difference.
'But if that were the case, wouldn't it also produce soot even without the chip?'


The performance according to ULF is now acceptable without any modifications. This morning, after warming up, I went directly from 50 to 100 km/h and it took about 6.5 seconds.
Just like before the tuning. The top speed is also okay.
Russian is pretty much non-existent at the moment - so that's also fine.

I would like to reiterate that I am reaching the maximum speed with the chipped ECU, but slower than usual. It's just not pulling as strongly as it should.

Thank you for your help!
Arne.

Hi.

Arne wrote:

Slightly stuck EGR valve - I currently have... There's nothing blocking the EGR valve; it's therefore open. I've already checked the hose and closed it, but there was no difference.

Hm, are you saying that if the valve is mechanically stuck inside, does it matter what's connected to it on the outside? Instead, try disconnecting the intake rubber hose from the EGR valve and make sure it's actually closed (you can check by feeling inside, or by using a syringe to move the vacuum diaphragm up and down).
It's conceivable that if the seal isn't 100% tight, it might only produce a slight amount of smoke at speeds between 1000-1800 RPM. However, with a chip installed, too much air might be drawn into the exhaust pipe, preventing the increased fuel injection from burning cleanly.

Best regards, Rainer.

Hi!

Arne wrote:

Is that the boost control valve, the one with the white cap? ==> Can I clean it somehow, or perform a function test?

No, it's only for swapping. It's attached to the injection molding wall (Audi) and has vacuum hoses and power cables connected to it. It can sometimes break.

Arne wrote:

AGR valve - I currently have one. There's nothing on the can from the AGR - so it's open.

That's okay, but it's illegal.

Arne wrote:

But if that were the case, wouldn't it also produce soot even without the chip?

Sure, but not great. That chip with the extra 30 horsepower will definitely cause some black smoke from your engine, although probably not as much as you're describing. The car behind you is still clearly visible in your rearview mirror.

If the problem occurred *after* the chip was installed, I would suspect the chip. However, if the engine ran smoothly for several weeks, it's probably not the chip. It sounds like you might have a pressure leak somewhere. Do you have any unverified sections of your pressure hoses or a faulty intercooler? Did the defect appear suddenly? Most chip tuners increase the boost pressure, and it's possible that a component couldn't handle the pressure.

Best regards,
Uwe

Hi everyone,

@Rainer - sorry if I'm being silly now - the rubber hose for the intake air - is that the hose with the wire around it at the back of the engine, or where exactly can I find it ?

@Uwe - I'll go ahead and replace that white valve!

I've probably driven about 6,000 kilometers with the chip installed. On the day I noticed the issue, I was driving at full throttle more often.

I've completely checked all the pressure hoses. I'll check again in a few days, though - maybe a little oil will have leaked out by then. - The coolant reservoir on the Corrado G60 is really badly hidden. I'd have to take a lot apart to actually see it.

'In any case, I will check both items (the N75 valve and the EGR valve, assuming Rainer tells me exactly where the hose is located).'

Thank you,
Best regards,
Arne.

You know, about that AGR valve, I don't believe it. It's never been activated, so why should it suddenly get stuck or be open now? Whatever was happening before shouldn't suddenly cause it to stay open, how would that even be possible!

Best regards,
Mirco

Hi.

Arne wrote:

@Rainer - sorry if I'm being silly - intake air rubber hose - is that the hose with the wire around it at the back of the engine, or where exactly can I find it

Okay, how many rubber hoses are there on the AGR valve that allow intake air to pass through?

@ Corrado: If he can't find the rubber hose connected to the EGR valve, is he sure he has deactivated the EGR correctly? I'm not so sure about that...

Best regards, Rainer.

[Translating...]

AARGH - it seems I've really been caught now.

I've switched back to a setup without the chip. The torque isn't the same as it was originally, and it still smokes a bit. (see above)

'Yesterday, my friend was driving behind me and told me I was emitting blue smoke. I immediately checked, and... ugh, there was actually blue smoke, and I'm also missing oil. The oil reservoir was full, but now it's only 2/3 full...'

Regarding the issues of soot and performance:
Tonight, I'm definitely going to try a different LMM (lambda sensor) and a different N75 (boost pressure control valve). Let's see if that's the problem. The power is okay, but the torque is terrible.


Und jetzt zum Blaurauch - was kann denn das wohl sein? Bisher (10tkm hat der kein Öl gebraucht! - Ich denke das hängt irgendwie mit der oben stehenden Problematik zusammen?!? - Gibt der Turbo den Geist auf? Kopfdichtung?

Thanks again for all your efforts!

Hi.

If the diesel engine is drawing in such large amounts of oil vapor, as appears to be the case with yours coming from the exhaust, it could create a "runaway" situation where the oil is burned, causing the engine to rev up unpleasantly and can only be stopped by stalling it.

The TDI often exhibits strange behavior at idle, such as misfiring or stuttering.

Since you haven't described any of those symptoms, I suspect that your oil is leaking directly into the exhaust.
In my opinion, the most likely causes of leaks are primarily the valve stems (exhaust side) and the turbocharger (exhaust-side seal).

Okay,

Last night, I reinstalled the chip.
Then I installed a different LMM and also a different boost pressure limiting valve. Unfortunately, it didn't work.

The diesel engine still smokes like crazy.
This morning, I noticed that after a longer, fast drive on the highway (20 km), the amount of smoke significantly decreased. It was almost normal. Then, after another 10 km on a country road, I was back to having the same problem with my Actros.

Yesterday, we also disconnected the connector from the needle lifter, and that stopped the smoking – but it also reduced the power. And it actually has enough power as it is.

Okay, here's the translation:

'Also, another thing: I have a Kat Original gasoline engine with a stock exhaust. Could that make a difference?'

Thanks again for the help, it's really great!
Arne.