[n54e90ftw]

UPDATED 9/29/2021

I have a 2007 335i, it got huge white smoke out of the exhaust (see picture and video below). It's from both the exhaust tips immediately, and non-stop. If you drive it for 2 miles, it will create 2 miles of thick smoke that blinds cars 100 ft behind for good.

Here's the video (engine starts at 1:15):
https://www.youtube.com/watch?v=mFrH046BZPE

Another video shot from the back of the car
https://youtu.be/U6KoIuUwy4o

I took the intercooler out as the first step, and to my suprise I drained about a quart of engine oil, YES, engine oil, from the intercooler for cooling down compressed air. (Could this be a sign of engine oil leaking into turbo compressor?)

Then I just removed the intercooler and test drove the car without turbo boost. White smoks is still huge and smelly. It doesn't smell like gas for sure, but not sweet either, it smells like strange chemical which I don't know anything similar to, not an expert on that.

I also tried replacing the coolant with pure distilled water. After that change, the smoke got a little bit lighter in thickness and less smelly, but still thick enough to blind car 80 feet behind for good. The car is throwing the following codes(see image attached). In summary, it has codes including misfiring at cylinder 1, 2, and multiple cylinders, interface EWS-DME electronic vehicle immobilization, control Klemme 15, digital DME motor electronics internal failure, Lambda probe behind catalyst, inlet VANOS variable cam control... and some other minor issues of brake light.

There's no wired engine noise, but the engine coolant level went low when you drive around, so I'm guessing somehow the coolant leaks into the either the engine combustion chamber or into the turbo.

But I'm not able to isolate where the coolant got leaked into the exhaust. Is it from the cylinders, or is it from the turbo cooling system.

Update on 9/1/2019:
I drained the coolant and the engine oil, they don't look mixed into each other. The coolant stays emerald green and engine looks dark brown since it's a mixture of old engine oil and newly added engine oil.
I also found the bottom of the engine intake air filter box to be filled up with a pool of engine oil, possibly originating from the turbo through the intercooler.

Update on 9/28/2021:
I finally decide to come back to this project.
Today I removed the intake manifold and OFH(oil filter housing). The OFHG(oil filter housing gasket) looks intact to me. The intake duct looks pretty dark with all the carbon residue, but probably not the cause of the white smoke.
Next move? Maybe I'll open up the engine head and check the cylinder head gasket, simply because it's more accessible from the hood. Some of you are suggesting removing the cat, and seeing through the pipes into the turbos to see if the inside is wet. Well, I'll do it if I have to, but I don't really have a proper set of vehicle jack stands to do it.

[srey]

Head gasket would be my guess, but that's pretty rare on the n54.

[rjahl]

Originally Posted by srey

Head gasket would be my guess, but that's pretty read on the n54.

My guess as well,

A long time ago I used cooling system pressure testers to identify cooling system leaks on marine engines. Tester mounts on the coolant tank Flange like a cap.

Pump pressure into the system and start the engine, pressure pulses or rapid increase in coolant pressure would indicate a head gasket issue.

Do they use the same tool on automotive engines?

[srey]

Originally Posted by rjahl

My guess as well,

A long time ago I used cooling system pressure testers to identify cooling system leaks on marine engines. Tester mounts on the coolant tank Flange like a cap.

Pump pressure into the system and start the engine, pressure pulses or rapid increase in coolant pressure would indicate a head gasket issue.

Do they use the same tool on automotive engines?

Yes. You can rent one from your local autozone.

[GEOS07335i]

My White Smoke was related to fuel injectors. What index are yours how many miles on them?

If you have downpipes see if you can get under the car and determine if you see any oil around the turbo. If the seals start to go and oil drips down into the downpipes it could also produce white smoke.

Check your oil see if if's milky (coolant in the oil) Oil Filter housing gasket has coolant channels not sure if they can mix or not but just wanted to throw that in there.

[n54e90ftw]

Originally Posted by srey

Yes. You can rent one from your local autozone.

Thanks, but I bought one from eBay, will arrive in a week. Autozone quoted $170 for renting, while I can buy the same thing from ebay for $40.

[JDang]

Originally Posted by n54e90ftw

Thanks, but I bought one from eBay, will arrive in a week. Autozone quoted $170 for renting, while I can buy the same thing from ebay for $40.

Well yes the initial cost is expensive, but they refund you the entire amount upon return don't they? It's $170 (perhaps cost of the product) incase you run off with the item lol. I rented an o2 sensor socket for $25 and they sent a refund for $25 back when I returned it when I was finished.

[n54e90ftw]

So I used coolant pressure tester and followed rjahl's suggestion. When I added some pressure to the reservoir and started the engine, pressure didn't change a bit. So I guess this could indicate that it's not the head gasket?

Any other guess is welcome. I will try to drain the engine oil then try running again for just a bit, see if smoke dies down at all. It could be oil, could be coolant. Or it could be than somehow coolant mixed into oil. When I drain the oil I'll see if it's a mix.

Originally Posted by rjahl

My guess as well,

A long time ago I used cooling system pressure testers to identify cooling system leaks on marine engines. Tester mounts on the coolant tank Flange like a cap.

Pump pressure into the system and start the engine, pressure pulses or rapid increase in coolant pressure would indicate a head gasket issue.

Do they use the same tool on automotive engines?

Here's the video:
https://www.youtube.com/watch?v=mFrH046BZPE

Originally Posted by JDang

Well yes the initial cost is expensive, but they refund you the entire amount upon return don't they? It's $170 (perhaps cost of the product) incase you run off with the item lol. I rented an o2 sensor socket for $25 and they sent a refund for $25 back when I returned it when I was finished.

JDang, you might be right.. but I already purchased this thing we I saw your post. Anyway thanks.

[wrrush]

can someone do a sticky about white smoke and the various causes because it can come from oil in turbos, leaking pcv valve of oil onto exhaust, oil and coolant mix, coolant leaks, various oil leaks ect and i see these posts almost daily and they just say, i have white smoke what do i do, it would be easy to refer them to sticky, unless there already is one and i missed it like a moron, thank you for the help in advance

[n54e90ftw]

Guys, I'm bumping up this thread once, because this issue still haven't been solved, and I plan to work on this car towards end of the year. Any hint or guess is appreciated!

[dpaul]

You've let the car sit this way for a full year?

White smoke on start up WITH A COLD ENGINE is the #1 classic symptom of failing injectors.

So, does the smoke eventually go away when you warm the engine up? Does it recur when you re-start the engine after it's warm?

Leaky injector very easy to diagnose in this kind of situation - let the car sit overnight, remove the sparkplugs, inspect for wetness and/or fuel smell.

Also, are you still losing coolant and how much coolant are you losing (i.e. how many ounces per mile)?

[335iN54enthusiast]

Check out my tips on diagnosing a smoking n54 in my you tube vids. Watch "335i N54 Enthusiast" on YouTube
https://www.youtube.com/channel/UCUH...np96CSleQFSvXw

[n54e90ftw]

Originally Posted by dpaul

You've let the car sit this way for a full year?

White smoke on start up WITH A COLD ENGINE is the #1 classic symptom of failing injectors.

So, does the smoke eventually go away when you warm the engine up? Does it recur when you re-start the engine after it's warm?

Leaky injector very easy to diagnose in this kind of situation - let the car sit overnight, remove the sparkplugs, inspect for wetness and/or fuel smell.

Also, are you still losing coolant and how much coolant are you losing (i.e. how many ounces per mile)?

The smoke never goes away, and will come out immediately when you start the car. Thanks on the leaky injector test tip, I'll try that when I start to disassemble the engine, which I think anyway I couldn't avoid.

I can't tell you exactly how much coolant I'm losing, because given the current condition of the car, I'll get pulled over within 5 minutes of driving.

Originally Posted by 335iN54enthusiast

Check out my tips on diagnosing a smoking n54 in my you tube vids. Watch "335i N54 Enthusiast" on YouTube
https://www.youtube.com/channel/UCUH...np96CSleQFSvXw

Thanks for the video, great video! I updated the original post with more observations. If you could take a look and comment, that would be very helpful. Thank you.

[mweisdorfer]

What does the oil look like? Does it look like coffee with a lot of creamer w/ some foam?

If so, it "might" be a head gasket. It could also be an internal leak in your OFHG too.

[n54e90ftw]

Originally Posted by mweisdorfer

What does the oil look like? Does it look like coffee with a lot of creamer w/ some foam?

If so, it "might" be a head gasket. It could also be an internal leak in your OFHG too.

Here's the colors of my engine oil and engine coolant. The oil doesn't seem to contain coolant, neither does the coolant contain oil. The engine oil smell a little sweet, but I compared with the smell of some castrol engine oil out of the bottle, they're pretty much the same. So at this point I think they're not mixed before going into the engine. But when I was removing my engine air filter box, I found quite some engine oil residue near the bottom of the air filter box. I suspect they came from the charge pipe, the intercooler, and initially from the turbo compressor.

[mweisdorfer]

Are you using a catch can?

[n54e90ftw]

Originally Posted by mweisdorfer

Are you using a catch can?

I'm not using catch can sir, the car looks stock to me.

[mweisdorfer]

Originally Posted by n54e90ftw

I'm not using catch can sir, the car looks stock to me.

Typically speaking, excessive white smoke is bad turbo seals.

If you take the cats off, and look into the turbos, there will be an oily residue inside the the turbo. This is not normal.

To cut down the amount of oil you are seeing in the FMIC, charge pipe etc., you should install a catch can or look into RB's catch can fix, which will almost eliminate all oil going into the intake system.

However, the above paragraph will not fix your immediate problem.

Sometimes installing a MHD tune and running stage 1 with the wastegate fix checked off can fix your issue, but don't be fooled by the "fools gold". At some point, your are gonna have to replace the turbos.

[n54e90ftw]

Originally Posted by mweisdorfer

Typically speaking, excessive white smoke is bad turbo seals.

If you take the cats off, and look into the turbos, there will be an oily residue inside the the turbo. This is not normal.

To cut down the amount of oil you are seeing in the FMIC, charge pipe etc., you should install a catch can or look into RB's catch can fix, which will almost eliminate all oil going into the intake system.

However, the above paragraph will not fix your immediate problem.

Sometimes installing a MHD tune and running stage 1 with the wastegate fix checked off can fix your issue, but don't be fooled by the "fools gold". At some point, your are gonna have to replace the turbos.

Thanks for the comments. I doubt that the white smoke was because of turbo seals on the compressor side, because the FMIC has been removed since last year, so whatever comes out of the turbo compressor is not going back into the intake now, and the turbo compressor outlet is now connected with several layers of plastic bags to collect whatever comes out. But if it's the turbo seals on the turbine side, it could be true, since the turbine is part of the exhaust system and hot exhaust mixture travels through it. Leaked coolant into the turbine might turn into white smoke.

So there might be two sperate problems in this car: engine oil leak from turbo compressor that caused the oil build-up in FMIC and air-filter box (but not the root cause of the white smoke); and coolant leak in the engine itself or the turbo's turbine that causes the white smoke? I know that the exhaust gas goes through the turbine to spool up the turbo, then goes to the downpipe, so if coolant leaks into this part of the turbo, it could turn immediately into hot steam because of the exhaust gas temperature.

[mweisdorfer]

Originally Posted by n54e90ftw

Thanks for the comments. I doubt that the white smoke was because of turbo seals, because the FMIC has been removed since last year, so whatever comes out of the turbo is not going back into the intake now, and the turbo compressor outlet is now connected with several layers of plastic bags to collect whatever comes out.

So there might be two sperate problems in this car: engine oil leak from turbo (but not the root cause of the white smoke); and coolant leak in the engine itself that causes the white smoke?

Does the white smile have a burnt/ sweet smell to it? If not, then I doubt the engine has an internal coolant leak.

There's only two causes of a coolant leak into the system that I am aware of :

1) head gasket (very rare on an n54)
2) internal leak of the OFHG (I see a post like this maybe once or twice a year, but that's it)

Take the Cats off the turbos and see if it's wet inside the turbo housing. If so, that's your culprit. Turbo seals.

You can try a product called no smoke made by Liqui Moly.

https://products.liqui-moly.com/oil-smoke-stop-4.html

Change your oil with 6.5 quarts of 5w-40 & add two cans of this. Don't run to WOT for 500 miles.

I don't think I have ever read about a coolant leak internally in the turbos. Oil leak yes.

[335iN54enthusiast]

Think it might be your fuel injectors not closing 100% would explain your misfires....but also like someone suggested..you NEED to pull off your downpipes to have a look at whats going on in your turbos...do you have shaft play? Do u have oil residue in your turbos...knowing that will help you pin point your problem. Otherwise like everyone here...youre just guessing.
Start the car up cold and see if theres droplets of fuel coming out of the bottom of your downpipes where they connect to your midpipes...that is an indication of bad injectors.

[torrque]

It's not injectors.... you can't blame injectors for the amount of oil you are dripping, or loss of coolant. I think you have a turbo failure. It could be leaking coolant into the exhaust too from the turbo cooling lines.
Hopefully only turbo's and nothing else; although the amount of oil you found in the intake tells me you have bad rings also, too much blow-by....