Smoking Bluetec
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MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
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From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
Smoking Bluetec
Hey guys, opinions please.
Our Bluetec started to smoke black upon brisk acceleration. We've had all the deletes done a couple years ago, this smoke thing is recent.
I asked in the W166 forum and one possibility offered was leaking injectors. Are there any other ideas and if the injectors are indeed the culprit, are there any drawbacks to not having them replaced?
Our Bluetec started to smoke black upon brisk acceleration. We've had all the deletes done a couple years ago, this smoke thing is recent.
I asked in the W166 forum and one possibility offered was leaking injectors. Are there any other ideas and if the injectors are indeed the culprit, are there any drawbacks to not having them replaced?
Senior Member
Joined: Jul 2011
Posts: 328
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2012 S350 Bluetec 4MATIC; 2011 ML350; 2005 C230k;
I would also start with injectors if you have black smoke. You can burn the pistons if the injectors are leaking. You can do injector leak test to find out which injector is bad and replace just bad one. Try to purchase BG245 sometimes it can help, but you don't want to ignore this for too long.
Senior Member
Joined: Mar 2017
Posts: 258
Likes: 50
R320, Astro, JSW, ST4
I would start with the simplest things, first.
Check the intercooler hoses closely for splits, tears, or leaking/loose connection. A leak smaller than you can hear, can be big enough to throw the air/fuel mix.
It can smoke before an error is thrown, and a tune file will be more tolerant of over-fueling than a stock file.
If the hose from turbo to intercooler ( hot side ) does a dip before coming up to the level of the intercooler inlet, hot oil will collect there, weakening the hose.
Look to see if these hoses are greasy on the outside. If so, degrease, run the car, and check again for source of the oil...
Check the intercooler hoses closely for splits, tears, or leaking/loose connection. A leak smaller than you can hear, can be big enough to throw the air/fuel mix.
It can smoke before an error is thrown, and a tune file will be more tolerant of over-fueling than a stock file.
If the hose from turbo to intercooler ( hot side ) does a dip before coming up to the level of the intercooler inlet, hot oil will collect there, weakening the hose.
Look to see if these hoses are greasy on the outside. If so, degrease, run the car, and check again for source of the oil...
Thread Starter
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 155
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
Thx! If the smoking continues (which it will), I may end up bringing it to an MB dealer for repair. I haven't the time to wrench on motors anymore.
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Senior Member
Joined: Mar 2017
Posts: 258
Likes: 50
R320, Astro, JSW, ST4
Before you go to the dealer pop the hood and take an old t-shirt or clean rag - wrap it around your hand, and wipe the backside/underside of the driver's side boost hose.
Comes from the front-left/driver's side of the motor, to behind the radiator, and is just below the the upper radiator hose.
One end or the other is likely gonna be a little greasy from the connectors weeping.
But if hose is wet or dripping or you can see nearby areas getting coated with oil, you may be able to feel a split in the hose.
Even if you have the dealer do the repair, you'll know what to expect from them.
If you still have the crankcase vent hooked up to the air inlet and feeding the intake with oil, there's no need for special tools to find a leak.
The oil will show it to you.
(That test is only useful in really marginal conditions, but it's a good way to justify more hours in a shop)
Comes from the front-left/driver's side of the motor, to behind the radiator, and is just below the the upper radiator hose.
One end or the other is likely gonna be a little greasy from the connectors weeping.
But if hose is wet or dripping or you can see nearby areas getting coated with oil, you may be able to feel a split in the hose.
Even if you have the dealer do the repair, you'll know what to expect from them.
If you still have the crankcase vent hooked up to the air inlet and feeding the intake with oil, there's no need for special tools to find a leak.
The oil will show it to you.
(That test is only useful in really marginal conditions, but it's a good way to justify more hours in a shop)
Thread Starter
MBWorld Fanatic!
Joined: May 2017
Posts: 1,234
Likes: 155
From: Montreal/Cape Coral FL
2012 X6 35i Sport, 2013 ML 350 BT, 2019 4Runner TRD Pro, 2020 CRV-AWD
Better late than never? LOL
Got around to checking that hose B34chBum completely dry. But thanks for the suggestion.
I guess I'll be bringing it to an MB dealer unless someone around Montreal can recommend a good indie.
Got around to checking that hose B34chBum completely dry. But thanks for the suggestion.
I guess I'll be bringing it to an MB dealer unless someone around Montreal can recommend a good indie.
