Im going to ask something daft ......

I keep seeing them pop up..... Whats a N75j valve or whatever it is ??? And whats it do ????

On the TDI the n75 valve controls the amount of vacuum applied to the actuator on the turbo to vary the vane position. I dunno what it does on the 1.8T....

Same thing, but to control the wastegate instead.

Its the solnoid valve next to the dump valve on intake pipe to turbo

Edited 27 April, 201115 yr by Volvomeg

Are they a tweek or is there 1 on mine already ?

There's one there already

The letter after it kind of refers to the boost characteristic the valve creates. There's lots of discussion over which ones work in what way, but consensus on the J version seems to be that it spikes higher, for slightly longer.

personally mate,

dont bother with one. Not worth it. I had one and sold it after 1-2 month. made the car run like ****.

the J valve is off old Audi turbos and basically it makes the car overboost for a second or so. Unless you get the car mapped with it on, I would stick to the std one.

In some cases they work well but in mine it was a big waste of money and as said made the car harrid to drive. was not smooth thats for sure.

billy

Can't they trigger limp mode sometimes? The J version that is.

Can't they trigger limp mode sometimes? The J version that is.

On a petrol or a diesel? I wonder what I have..... (not fuel wise )

I meant petrol, but I suppose it could do on a diesel too.

I thought because it made boost spikes bigger, it could sometimes trigger limp mode.

A new one – standard F version, mind – can also make a 17705 error code disappear

There is a useful description of what the N75 valve does in post 3 in the VWVortex link below:

http://forums.vwvortex.com/showthread.php?2666114-1.8t-Technical-Forum-Guide-FAQs-Tuning-Modification-Assistance-Troubleshooting