Blue smoke on high throttle, order of operations?

[cole3498]

Hi all, I am getting some light blue smoke out of the exhaust when I am above 4000 rpm and just after letting off, as I have been told by multiple people cruising with me. I am not consuming any oil at the moment, nor am I seeing any indication of oil in coolant or vice versa, and there is no smoke at idle or when driving normally. Car is a 2016 non-pp with 65,000 miles. Only mod is a GH tune with appropriate plugs and sensors. I've done quite a bit of reading here and have compiled a list of potential causes, but unfortunately I don't have a garage and can't do any work myself. I do have a mechanic I trust but was hoping to get everyone's thoughts on what order of operations to test for the issue (hoping to save some money finding the issue faster). My thoughts are:

1. Car already has a seeping timing cover (light coating of oil on the outside picking up dirt). This is scheduled to be fixed (still deciding if I want to do the pump chain etc at the same time with only 65,000 miles). This should not be causing smoke out the exhaust as far as I know.
2. GH IC will also be installed at this time, will have them inspect the one that comes out and the inlet outlet for oil.
3.Turbo seals and hoses next? Thinking it could be a turbo issue seeing as it is happening in high rpm's with a tune for higher boost. Hoping the turbos themselves aren't going this early.
4. PCV system. I have no CEL codes or loss of power or any other issues with the way it is running, but this could still allow oil into the wrong places I suppose.
5. Hoping not, but last effort would be taking the top end apart for a compression test and a look at piston rings, valve seals, etc?

TIA for advice on how to go about this.

 

[Texas Marauder]

Likely a bad turbo oil seal. Exactly what mine did, WOT and let off and the smoke would roll. No oil usage and no noticeable smoke under normal driving. An oil seal ring came off the exhaust side. I found it stuck in the oil return. Closed throttle at high RPM creates a vacuum in the exhaust. Drove it 2 years, 40,000 miles with no ill effect till I could replace the turbo.

Pic of seal ring pulled from the oil drain.

 

[BradM]

When I went catless on my build, I could clearly see oil smoke on lifting after a pull (even with new turbos). I did some tests and found the design of the PCV system allowed crankcase pressure to build because the PCV connector on Bank 2 (front of car) has a very small passage hole (it's not wide open like the Bank 1 connector). I added a vent to my oil cap and the problem went away. For the h$ll of it, loosen your oil cap or remove the Bank 2 PCV connector from the valve cover and see if the smoke goes away. You have to remove the connector, not the hose (I think it's 1/2 turn to the left). You'll throw a code for PCV but it's an easy test and will eliminate one possible cause. Put a rag around whatever you loosen because it'll throw oil. I think I posted something here about my tests.

 

[BradM]

Likely a bad turbo oil seal. Exactly what mine did, WOT and let off and the smoke would roll. No oil usage and no noticeable smoke under normal driving. An oil seal ring came off the exhaust side. I found it stuck in the oil return. Closed throttle at high RPM creates a vacuum in the exhaust. Drove it 2 years, 40,000 miles with no ill effect till I could replace the turbo.

Pic of seal ring pulled from the oil drain.
View attachment 92869

With all due respect, I don't think it's physically possible for the oil seal to come off when the turbo is assembled. Each seal is captured in a race. What you likely experienced is the oil seal came out when you disassembled the turbo. Here's a photo of our turbos blown apart. With no oil seal, you would have blown massive smoke all the time as the oil pressure would have pushed oil out the hot side whenever the engine was running.

 

[Texas Marauder]

That's my best explanation. The turbo was still on the engine. I pulled the drain line loose and that ring was up in the drain hole. I pulled it out with a hook.

 

[shoblock]

Hi all, I am getting some light blue smoke out of the exhaust when I am above 4000 rpm and just after letting off, as I have been told by multiple people cruising with me. I am not consuming any oil at the moment, nor am I seeing any indication of oil in coolant or vice versa, and there is no smoke at idle or when driving normally. Car is a 2016 non-pp with 65,000 miles. Only mod is a GH tune with appropriate plugs and sensors. I've done quite a bit of reading here and have compiled a list of potential causes, but unfortunately I don't have a garage and can't do any work myself. I do have a mechanic I trust but was hoping to get everyone's thoughts on what order of operations to test for the issue (hoping to save some money finding the issue faster). My thoughts are:

1. Car already has a seeping timing cover (light coating of oil on the outside picking up dirt). This is scheduled to be fixed (still deciding if I want to do the pump chain etc at the same time with only 65,000 miles). This should not be causing smoke out the exhaust as far as I know.
2. GH IC will also be installed at this time, will have them inspect the one that comes out and the inlet outlet for oil.
3.Turbo seals and hoses next? Thinking it could be a turbo issue seeing as it is happening in high rpm's with a tune for higher boost. Hoping the turbos themselves aren't going this early.
4. PCV system. I have no CEL codes or loss of power or any other issues with the way it is running, but this could still allow oil into the wrong places I suppose.
5. Hoping not, but last effort would be taking the top end apart for a compression test and a look at piston rings, valve seals, etc?

TIA for advice on how to go about this.

Do you have a catch can? If you don't have a catch can, I would advise getting one. Make sure you hook the hoses up correctly, or it could also cause a blue smoke issue.
SHOBLOCK

 

[Mahu24]

I have catless down pipes, 3rd cat delete, stock turbos, and even with a dual valve catch can it still smokes on WOT. 34k miles

 

[shoblock]

What changed? When did the car start smoking? I would list the mods and their dates, and the date you first noticed the smoke. One omitted or incorrect hose connection could cause this, especially hoses to the catch-can. If the vapor intended to go to the catch can goes to the intake, it will cause an issue like you're describing. Number 4 on your OP is the one I would deep dive.
SHOBLOCK

 

[cole3498]

What changed? When did the car start smoking? I would list the mods and their dates, and the date you first noticed the smoke. One omitted or incorrect hose connection could cause this, especially hoses to the catch-can. If the vapor intended to go to the catch can goes to the intake, it will cause an issue like you're describing. Number 4 on your OP is the one I would deep dive.
SHOBLOCK

Tune was August of 2023, first noticed the smoke October 2024. Only thing in between was a group road trip where I beat the **** out of it, no other mods or anything. I don't currently have a catch can, but it's been recommended in this thread so I will put it on my to do list!

 

[yaycandy]

Mine smokes all the time catless with a catchcan. It dont burn oil at all. Always when the revs are held around 3,000rpm or more. I get laughed at all the time by people saying i blew it up. But it runs very well. Just makes alot of oil smoke at wot and decel holding gears. Even on my exhaust video from years ago you can see it at wot or 3/4 throttle. I figure it from the intake valves having a coating on them and pushing into the chamber when the boost kicks in. But who knows. Tune and catless were the first things i did in 2018 on my original engine. 2019 got a new engine and turbos and literally the same smoke. Im guessing putting cats on it would make it stop. Actually a conversation a couple years ago with the guy that did my engine work suggested that going catless affected the seal pressure on the way the turbos are designed but that was just his professional guess

 

[kryptto]

Mine smokes all the time catless with a catchcan. It dont burn oil at all. Always when the revs are held around 3,000rpm or more. I get laughed at all the time by people saying i blew it up. But it runs very well. Just makes alot of oil smoke at wot and decel holding gears. Even on my exhaust video from years ago you can see it at wot or 3/4 throttle. I figure it from the intake valves having a coating on them and pushing into the chamber when the boost kicks in. But who knows. Tune and catless were the first things i did in 2018 on my original engine. 2019 got a new engine and turbos and literally the same smoke. Im guessing putting cats on it would make it stop. Actually a conversation a couple years ago with the guy that did my engine work suggested that going catless affected the seal pressure on the way the turbos are designed but that was just his professional guess

i love it. btw I never really have revved mine up to limit and recorded it, so I couldnt tell ya how much smoke mine blows, I look out the front windshield not the back...

 

[kryptto]

WAIT - I got smoke too after catless.... just wait for it.

PS - it was before I had a dual catch can - was the old crappy J&L dirty side only.

 

[yaycandy]

WAIT - I got smoke too after catless.... just wait for it.

PS - it was before I had a dual catch can - was the old crappy J&L dirty side only.

I just have the jlt single since like 2019 or so.