Oil leaking where turbo hooks up to wastegate and swmokes like crazy

There are several possible reasons why the turbo on your 2002 Golf TDI might not be engaging:

1. Boost pressure issue: The most common cause of a non-engaging turbo is a boost pressure issue. This can be caused by a leak in the intake system, a damaged turbocharger, or a clogged air filter.
2. Malfunctioning wastegate: The wastegate is a component that controls the amount of exhaust gas that flows through the turbocharger. If the wastegate is malfunctioning, it may not allow the turbo to engage properly.
3. Faulty turbocharger control solenoid: The turbocharger control solenoid is responsible for regulating the amount of pressure that goes to the turbocharger. If the solenoid is faulty, it may not be able to control the pressure properly, leading to a non-engaging turbo.
4. Electrical issue: There may be an issue with the electrical components of the turbo system, such as a faulty wiring harness, sensor or control module.

To diagnose the problem, you can check for any visible leaks in the intake system or damage to the turbocharger. You can also check the wastegate for proper function and inspect the turbocharger control solenoid for any signs of damage or failure. If you are unsure how to perform these checks, it is recommended to take your vehicle to a qualified mechanic for a proper diagnosis and repair.

On the turbo housing.

it depends on the turbo. generally you need to change the manifold to one that has a t3 flange, change the down pipe to one that matches up to the turbo, plug the oil feed to the turbo and run a new one (usually off the head or T'd into the oil pressure sensor, if the new turbo doesn't have coolant ports you need to plug the coolant lines that went to the old turbo, modify the intercooler piping off the turbo, you may need a different intake tube, and if the new turbo doesn't have a internal wastegate you will need an external one and the manifold will need an external wastegate flange.

Check that the turbo's charge pipes aren't leaking anywhere. (The boost side, to the intercooler, to the manifold).

If they're not, check for exhaust leaks.

If that's not it, the turbo isn't functioning properly, or the wastegate (bypass valve) is stuck open.

in your car the air ventilation system is freeze up causing a build up of pressure which caused the oil to burst out. there is the mosture sludge build up under the oil fill cap . its advisable to clean everything up and then check out by starting the car. also spray crab cleaner in the throttle body and check out. as per me the problem is causing because of :-- I guess the breather vent tube was full of oil - frozen in there somehow. Must have to do with that sludge buildup on my oil fill cap. This is the one coming off the front on the left side of the oil filter. It goes down under the engine. This blockage caused a pressure buildup in the crankcase which caused oil to blow by the pistons and into the combustion chamber and out into the air intake hose and throttle body. get the spark plugs removed and cleaned up all the oil. The reason it sputter is because of all the oil in the combustion chamber. No air could get in. get the oil change and insulate the breather pipe in case of future freeze ups. This will help. Thanks please keep updated.please do rate the solution positively .thank you for using fixya

This could also be Safe mode, the below text may help you.

What Is Safe Mode?

Safe mode is the set of parameters that the car will use if it believes there
is a fault with the engine that could cause irrepairable or long term damage.

How Can I Tell If It Is Safe Mode?

If your car suddenly lost power but before that you didn't notice any problems.
If there isn't vast plumes of smoke coming from the exhaust.
If the oil level is OK. If you had all 3 of those, it is almost certainly safe mode.

What Causes Safe Mode?

Generally it is an excess in expected boost pressure entering the engine.
This excess boost from the turbo tends to happen for 4 reasons.

The boost pressure sensor (MAP sensor) is faulty.
The wastegate is seized shut or slightly open.
The wastegate actuator is faulty.
The air line to the wastegate actuator is damaged or off.

Obviously, if the sensor is faulty, it will tell the ECU lies about the boost pressure.
If the wastegate assembly fails in any way it will fail to open to bypass the turbo.
The turbo will continue to spin up, increasing the boost pressure, causing the fault.

How Can I Fix It?

Initially I would suggest disconnecting the battery for 5 minutes (make sure you know your
radio code before doing this), this will turn safe mode off and your car should run normally
again. Drive home with a bit of care, you may find the car might never do it again. If it does
go into safe mode again, you know you have a real problem and not just a glitch.

Wait for the car to cool down and see if the wastegate arm moves freely.
Use the search function of the site for "wastegate service" to see how
you can possibly free up the wastegate assembly which could be seized.

Check the pipe work to and from everything to rule out leaks.

Try and borrow a MAP sensor to test.

As a last resort, book in with a smart specialist who will diagnose the problem

The wastegate may be mal-adjusted now after fitting the new turbo, it sounds like it is shunting boost pressure down the exhaust thru the wastegate valve which is vacuum operated.

Hello, I am a Saab technician from upstate new york. It sounds to me that the turbo wastegate rod may be seized to the turbo control valve. The easiest way to try to fix this is to spray penetrating oil on the turbo valve/ wastegate rod and work it back and forth with a pry bar. Many times u can also heat this up with a torch and pray. If those two things don't work than the turbo valve itself is seized into the guide hole machined into the turbo. good luck.

I don't know much about Subaru but I expect the turbo wastegate is controlled by vacuum which is switched by the engine management system.

In the old days the turbo wastegate was normally closed and the manifold pressure was fed into a servo which opened the gate at the predetermined pressure.

The new way of doing things is to have the wastegate normally open and the turbo producing no pressure until the engine management decides the time is right and it switches a vacuum supply to a vacuum servo which then closes the wastegate. With this system the wastegate is constantly moving and so is unlikely to give trouble though the vacuum servo sometimes leaks and vacuum lines give trouble.

A fellow I know had a similar problem where the engine check light would light up and he would lose performance. In theory this was because of an overboost condition but the repair shop after fiddling around with it for a week fitted a new EGR valve to produce a cure.

Check vacuum pump. Be sure lines are good all the way to to wastegate soleniod. be sure wastegate solenoid has power. Confirm rod is connected to solenoid and turbo wastegate.
Also check all plumbing for leaks.