Lack of turbo after I go through water

Bleednight said:

The oil level is right and it has the classic black color.

Click to expand...

As long as it's the classic black.

White/grey smoke is oil being burned around your turbo. If your turbo has got up to temperature (extremely hot) and then been doused in cold water, the sudden temperature change can cause fatigue in the turbo housing. If this happens enough, cracks can appear. The turbos are being cooled to a maintainable temperature by a constant oil feed which keeps the turbo cool enough so that the internals don't weld themselves together. There are a few possibilities of what has happened:

A) There is a crack and you're losing oil into the turbo casing/FMIC which is in turn being burnt on the hot side, causing white/grey smoke, and your turbo is in limp mode because of mixture

B) Your turbo has seized due to oil leak, so you are burning excess oil on hot side

C) Your turbo has blown due to temperature fatigue/oil loss and you've got oil running into the charged air feed

If you are saying that the car is running to 2100 on it's own, this could possibly be what is known as 'run away' (early warning signs there of), which is when oil is being forced into the combustion process by it's own accord, and is causing the car to over fuel itself. If you encounter a runaway while driving, the car will start accelerate uncontrollably which may cause you to crash, depending on your driving skill and the ability to keep your calm or not. A stationary runaway will basically destroy the engine if not stopped in time. Depending on conditions, the engine might even rip itself open, spraying shreds and pieces all around the place.. Please take a minute to familiarize yourself with what engine run away is, and how to deal with engine run away. This can save both your engine and your life should you ever experience it.

Wiki link --- https://en.wikipedia.org/wiki/Diesel_engine_runaway
Stopping runaway --- https://www.carthrottle.com/post/w8ookb3/


My advise would be first check for oil leaks /oil buildup at the FMIC connections. Easiest way to do this is to create an oil drain plug by drilling a 3mm hole in the pipe directly after FMIC, and seeing how much oil flows out. Plug the hole back up with an M3 screw.

Best case scenario, turbo in limp mode
Worst case scenario, blown turbo and debris (oil and impeller fins) dispersed around your engine internals.

I would say get it on vagcom and read the fault codes that are being thrown up. It could be N75 however that wouldn't explain the smoke. If the N75 was at fault it would not actuate the turbo and you would just have limp mode. The reason for power when it happened and then not in the morning is that during the 5/6 hours of not being used, the turbo has cooled down and the casing has essentially shrunk, which would make cracks etc. more susceptible to do their thing.

It's hard to diagnose from behind a keyboard but the mechanic should check all possibilities. As I said, vagcom should point you in a better direction.

Hopefully it's a bad boost sensor or N75.

Yeah I'd say get rid of or clean the EGR first as mine had similar symptoms before, that or maybe the plug under the battery needs removing as the rain is flooding the CCU.