Turbo clean

[Richy-one-kit]

Hi guys first ever post ! So be nice.

Has anyone ever cleaned turbo on the 1.6hdi turbo with mr muscle? If so how was it done and what part of turbo was disconnected?

Reason I’m wanting to clean it as I’m getting an under boost code and Iv already replaced the
Map
Maf
Boost solenoid
Blanked egr
I’m at a totally loose end please help

[GiveMeABreak]

We don't support Emissions disabling here of which the EGR is part of - please read the AUP first:

AUP

As you've already done this, the engine ECU will not be getting correct readings and will be changing other settings that will likely cause issues - so I suggest you un-blank it. The EGR is only operated under certain conditions and controlled by the engine ECU to perform certain functions which can affect the air and fuelling calculations. Blanking this is not only illegal for road going vehicles, but will also make finding your original issue much more difficult.

Typically, the EGR has the following functions:

The rate of exhaust gas recycling (EGR) is increased by acting on the following parameters:

• The reduction of the inlet pressure
• The rate of opening of the EGR electrovalve valve

Engine hot: The engine ECU controls the EGR throttle (cold air meter) and closes the inlet air heater throttle (hot air meter) to reduce the inlet pressure. The more the EGR throttle (cold air meter) is closed the lower the inlet pressure and the greater the rate of exhaust gas recycling.
Engine cold: The engine ECU controls the inlet air heater throttle (hot air meter) and closes the EGR throttle (cold air meter) to reduce the inlet pressure. The more the inlet air heater throttle (hot air meter) is closed the lower the inlet pressure and the greater the rate of exhaust gas recycling.

The engine ECU also determines, in accordance with engine maps, the percentage opening of the EGR electrovalve.

[411514]

I've not done so on that particular car, but have done it on a few others, with occasionally successful result. Does thus turbo even have VNT though? If so, you're best removing it completely from car to clean, that way you can rinse it out when done.

I'd unblank the EGR if I was you. There's a chance that will be contributing to the fault - some vehicles, don't know if this is one of them, also use the EGR as a sort of wastegate, in reverse of its normal function, to vent inlet air to the exhaust, e.g. on abrupt throttle lift-off.

[RichardW]

Depends on the age of the engine and the power output. In the original 16V version the 90 BHP had a std waste gate whereas the 110 version had a VNT - with a vac actuated boost controller (on the back of the engine). Probably all the later engines have a VNT. Easy to check on earlier engines, the actuator is right on the front of the turbo, with the engine off you should be able to push it down easily, and then it should return quickly. When the engine is started the vac should pull the actuator down. Usually faults with the VNT result in overboost as the default is the full boost position.

[admiral51]

If it has a double butterfly air doser i would def check that it is not sticking