[ArturM]

Loud DPF regeneration, normal? (Fixed)

My 2012 ML350 Bluetec exhaust/DPF system gets frequently
(3 times a week) very loud.
I know that it's a DPF regeneration process but what worries me is
that the exhaust sound gets very loud and annoying
(deep bass resonance, sounds louder that AMG 6.3):

https://www.youtube.com/watch?v=fBFyxgKUW2M&feature=youtu.be

Is this normal, do you have the same experiences?
Of course Mercedes dealer doesn't have a clue about this,
they've found nothing, no explanation.

 

[EricM]

I've never noticed it in my ML but I have a tough time telling when it regens anyway. On my Duramax however, the exhaust note has that same deeper sound when in regen. I believe the sound is actually intake resonance rather than exhaust sound because the Duramax actually uses what is essentially a throttle to reduce intake airflow to create a richer fuel mixture and consequently higher EGTs during a regen. I suspect most diesels with a DPF do something similar so the sound you're hearing is probably normal. The only real difference I'm aware of around regen strategies is that GM uses an extra injector to directly inject fuel into the exhaust while everyone else uses "post injection" (injecting extra fuel into the cylinders on the exhaust stroke).

 

[Vortecpwr]

I have driven several of these diesel where they should go into regen while I am driving. I have yet to notice anyone going into the regen mode. I just put 1k miles on a sprinter with your same eng and not once did I notice a regen mode. It even got 19.97 miles per gallon with me driving it. Its our roadside vehicle.

ALSO I do not think it will continue regen when at idle or sitting still.

 

[20swrt]

My 2012 ML350 Bluetec exhaust/DPF system gets frequently
(3 times a week) very loud.
I know that it's a DPF regeneration process but what worries me is
that the exhaust sound gets very loud and annoying
(deep bass resonance, sounds louder that AMG 6.3):

https://www.youtube.com/watch?v=fBFyxgKUW2M&feature=youtu.be

Is this normal, do you have the same experiences?
Of course Mercedes dealer doesn't have a clue about this,
they've found nothing, no explanation.

From watching this video it's hard to tell. How are you certain it's doing a regen? 3x a week is too often IMO. Normally it's should regen every 600-800 miles. Also, do you notice the loudness when going down the freeway ? Next time try to notice how hot are the gasses coming out of the exhaust. Careful, coz you can ignite paper with the exhaust alone.

 

[ArturM]

From watching this video it's hard to tell. How are you certain it's doing a regen? 3x a week is too often IMO. Normally it's should regen every 600-800 miles. Also, do you notice the loudness when going down the freeway ? Next time try to notice how hot are the gasses coming out of the exhaust. Careful, coz you can ignite paper with the exhaust alone.

Down the freeway the sound was even louder:frown

Yesterday my car suddenly lost all power, no warning lights just no power,
so I got back it to the dealer (a better one). They could not find any falults in the computer and finally traced it to the NOx sensor. The sensor was replaced but the sound still stays the same. They said that it's definately not normal, so investigation continues. They also found turbo exhaust leak causing turbo lag and some ticking noise during hard acceleration.
I'll keep you updated about this repair.

 

[20swrt]

How many miles on the truck? Is this driven daily ? What is your daily commute distance and average mph (one way) ? Also ave and one way MPG? I really cannot think of why it should make a loud noise. When you say "no power". Do you mean. Engine died or just would not increase rpm? Cannot drive fast perhaps ?

 

[ArturM]

How many miles on the truck? Is this driven daily ? What is your daily commute distance and average mph (one way) ? Also ave and one way MPG? I really cannot think of why it should make a loud noise. When you say "no power". Do you mean. Engine died or just would not increase rpm? Cannot drive fast perhaps ?

The truck has 55000km on odometer, driven daily 50/50 city/highway, average consumption is around 12,5L/km. By lost power I meant I could not accelerate or incerase rpm but the engine didn't die, just lost power and I had to pull over.

Dealer said if NOx sensor has been faulty for a long time it could have damaged the catalytic converter.

 

[Mac]

Perhaps if the NOx sensor was faulty and for a long time, it's the particulate filter that's damaged --e.g., plugged up.

 

[20swrt]

How far do you drive daily? Pls check if the turbo actuator moves when you rev the engine. Open the hood and observe. It's a little bigger than a matchbox in front of the turbo. The weird part is no check engine light.

 

[ArturM]

Update. My issues were finally fixed by replacing the seals around turbo charger and replacing a leaking
intercooler hose. They also changed some part behind the turbo but I don't know what was it.
No more strange noises from exhaust!

 

[ubrak]

Update. My issues were finally fixed by replacing the seals around turbo charger and replacing a leaking
intercooler hose. They also changed some part behind the turbo but I don't know what was it.
No more strange noises from exhaust!

I have the same problem at my 350bt -12. The car regen about evry 100km. Many times a week. But i dont know why.. Replesed: nox sensors, exhaust gas temp sensor, turbo inlet seal, air fileres. But no luck. The regen prosess runing about evere day.. A also tried to change te dpf it self, no luck. Also updatet to latest software from Star. I cant understsnd why this regen prosess runs so often. NO alarms in star diag. Can someone give me some tips??

 

[ubrak]

ArturM. This is an old thread, but i hope you see this reply.

I'm a ML350bt 2013 owner, and i have the exact same issu as you. Often regeneration, 4-6 times a week, and loud resonanse when regeneration is running. Car works fine, but it regenerates and regenerates. Rpm up to 800, engine fans running fast and loud resonanse like your youtube video. Mycar is exactly like you describe in the post. I am happy you solved your problem👍 But du you know exactly what they replaced to fix the car? You say ic hose, left or right?? Turbo seals, du you men the red inlet seal? And something behind the turbo.. Can you help me😅 Im going crazy of this.. I have no engine fault stored in Star diagnose. All seem fine, but it isnt.Regards Kim in Norway.

 

[ArturM]

ArturM. This is an old thread, but i hope you see this reply.

I'm a ML350bt 2013 owner, and i have the exact same issu as you. Often regeneration, 4-6 times a week, and loud resonanse when regeneration is running. Car works fine, but it regenerates and regenerates. Rpm up to 800, engine fans running fast and loud resonanse like your youtube video. Mycar is exactly like you describe in the post. I am happy you solved your problem👍 But du you know exactly what they replaced to fix the car? You say ic hose, left or right?? Turbo seals, du you men the red inlet seal? And something behind the turbo.. Can you help me😅 Im going crazy of this.. I have no engine fault stored in Star diagnose. All seem fine, but it isnt.Regards Kim in Norway.

Hi, check your intercooler hoses for leaks, especially the metal rings connector to intercooler, if they leak you'll get frequent DPF regenerations. I had it happen again last year and after replacement (second time) of right side intercooler hose the problem is gone.

 

[ubrak]

Hi, check your intercooler hoses for leaks, especially the metal rings connector to intercooler, if they leak you'll get frequent DPF regenerations. I had it happen again last year and after replacement (second time) of right side intercooler hose the problem is gone.

Thank you so much for replying me I replaced the right side IC hose yesterday, complete hose, include sealings. But nu luck. Regenerated again today after 100km. The left side hose i have not touched. But i not see any leaks at the connector to the intercooler. If it leak, should it be some wet oil around the connector?? So far i have replaced almost the half car.. New diff preasure sensor, new nox sensors, new turbo inlet seal, new (used) dpf, new egt sensors and more.. But my car continue to regenerate almost on clock every 100km. Then it regenerates for about 30km, and so is the syclus. Also i have the deep resonance sound when regen is going, like a V8. My car is 100% like you described your car, and like your youtube video.

Regards Kim, Norway.

 

[ArturM]

Thank you so much for replying me I replaced the right side IC hose yesterday, complete hose, include sealings. But nu luck. Regenerated again today after 100km. The left side hose i have not touched. But i not see any leaks at the connector to the intercooler. If it leak, should it be some wet oil around the connector?? So far i have replaced almost the half car.. New diff preasure sensor, new nox sensors, new turbo inlet seal, new (used) dpf, new egt sensors and more.. But my car continue to regenerate almost on clock every 100km. Then it regenerates for about 30km, and so is the syclus. Also i have the deep resonance sound when regen is going, like a V8. My car is 100% like you described your car, and like your youtube video.

Regards Kim, Norway.

Kim, did you check the other one by squeezing it and looking for cracks? The other explanations are either your DPF is clogged or not programed into ICU or your engine doesn't perform optimally generating excessive shoot due to some problem with shot turbo, injectors, PVC oil separator, EGR, boostleak or thermostat. I would suggest to go to the dealer and connect it to stardiag.

 

[ubrak]

Kim, did you check the other one by squeezing it and looking for cracks? The other explanations are either your DPF is clogged or not programed into ICU or your engine doesn't perform optimally generating excessive shoot due to some problem with shot turbo, injectors, PVC oil separator, EGR, boostleak or thermostat. I would suggest to go to the dealer and connect it to stardiag.

Hello again First: dpf is fine, i replaced it with a new dpf (used), no change. PVC oil separator is also new. Stardiag connected yesterday, NO codes or errors, all fine.

So, i removed the LEFT intercooler hose yesterday (right one is allready new). It have NO cracks. BUT, it is very atomized / smuzzy around the metal connectors, especially around the intercooler connector as you mentioned This left hose is very expencive 3 x more than the right one. 380 euro for left, and 120 euro for right. But as my left hose has no cracks, it was possible to replace the seals in both ends of the left hose. Its a black coned seal in both ends. The dealer receives the seals tomorrow, as the was not in stock. I will replace the new seals imediately to morrow, and post back. I have a feeling of this is the problem. Becauce it was very dirty / smuzzy / atomiced around the hose connection to the intercooler at left side. I suppose it is a preassure leak here.

 

[ArturM]

Hello again First: dpf is fine, i replaced it with a new dpf (used), no change. PVC oil separator is also new. Stardiag connected yesterday, NO codes or errors, all fine.

So, i removed the LEFT intercooler hose yesterday (right one is allready new). It have NO cracks. BUT, it is very atomized / smuzzy around the metal connectors, especially around the intercooler connector as you mentioned This left hose is very expencive 3 x more than the right one. 380 euro for left, and 120 euro for right. But as my left hose has no cracks, it was possible to replace the seals in both ends of the left hose. Its a black coned seal in both ends. The dealer receives the seals tomorrow, as the was not in stock. I will replace the new seals imediately to morrow, and post back. I have a feeling of this is the problem. Becauce it was very dirty / smuzzy / atomiced around the hose connection to the intercooler at left side. I suppose it is a preassure leak here.

The connector should be dry and clean if it is wet it means air leak. Please keep me updated about your progress.

 

[ubrak]

The connector should be dry and clean if it is wet it means air leak. Please keep me updated about your progress.

Okey, status today Removed the left IC hose, not oily, but verry dirty arround the connector to IC. Very hard oily dust around the entire hose. Both arround the connector to IC, and longer down by the backside of headlight. There has clearly been a preassure leak from the connector. I removed the old seals in both ends of the hose, and replaced with new seal rings. The new seals was obviously bigger than the old ones. The old ones must have shrunk over time, by the heat. So status for now is that the right hose is completely new, and the left hose has new seals in both end. I have to give it some days, then I'll see what happens.

But one question to you, when yours ML350bt is fresh, how is the regen syclus?? How long do you drive between the regens? 500km -1000km?? What is about normal?

Just in case, part number for the left hose seals is A0219976645 and A0219976545. Dealer told me only the om642 blutech engine having this seals. Older om642 is completely different.

Again, thank you so much for replying this old thread, it is possible you solved my regen nightmare.

Kim, Norway

 

[ArturM]

Okey, status today Removed the left IC hose, not oily, but verry dirty arround the connector to IC. Very hard oily dust around the entire hose. Both arround the connector to IC, and longer down by the backside of headlight. There has clearly been a preassure leak from the connector. I removed the old seals in both ends of the hose, and replaced with new seal rings. The new seals was obviously bigger than the old ones. The old ones must have shrunk over time, by the heat. So status for now is that the right hose is completely new, and the left hose has new seals in both end. I have to give it some days, then I'll see what happens.

But one question to you, when yours ML350bt is fresh, how is the regen syclus?? How long do you drive between the regens? 500km -1000km?? What is about normal?

Just in case, part number for the left hose seals is A0219976645 and A0219976545. Dealer told me only the om642 blutech engine having this seals. Older om642 is completely different.

Again, thank you so much for replying this old thread, it is possible you solved my regen nightmare.

Kim, Norway

My regeneration cycle now is more that every 500-800 km depending on driving conditions city/highway. Hope that your nightmare is now solved I very well remember this problem bugging me for a long time without any solutions, explanations from the dealer. I'm amazed how dealers do not understand the way these engines operate. What's your mileage on your truck, mine now is 230K km.

 

[ubrak]

Regen cyclus at 500 - 800km is very good. I hope my car end up with the same cyclus as yours In fact my car has regen very often for the last two years. But the last 6 monts it have been even worse. And i decided to try solve the problem, because it frustrated me. Mercedes dealer connected star, and scanned the car. Answare, No problem, your car is fine. That's the way it should be. But i was never confortable with te answare from mercedes. Im not happy with the dealer, do not think they are particularly good. Local "mercedes heros" have more knowledge. My ML has 125000km at the clock. I will post back after som days. Thanks again