Turbo valve??

[Nissanpatrol97]

My nissan patrol 2.8td y60 has a valve fitted on the turbo, and when the engine hits about 2500-3000 Rpm the valve blow off, sounds like a lorry .. What is this valve for?

I've had patrols 3.3 1988 and 3.0 2002 and they did not have a valve fitted.

Its making the engine loose power, and i need power to pull heavy loads. Can i block the valve, or adjust it to a higher bar/psi ?

https://i.ytimg.com/vi/KM8lL8P_W2Q/maxresdefault.jpg ( foto of the engine and turbo ) it's on the front.. round thing/valve on the Turbo.

[dom14]

I'm guessing you're referring to the Dawes valve??!!

By the sound of your description, it's not working properly.

May be you're up for a replacement?

[BigRAWesty]

On the turbo??
To me it sounds like a blow off valve that may be set to low or stuffed
I've always though deisels didn't need a blow off valve but I know of a few who have em now??

[Nissanpatrol97]

Her is a foto of a patrol engine, https://i.ytimg.com/vi/KM8lL8P_W2Q/maxresdefault.jpg. It is the valve on front of the turbo (down right corner in the foto) it's releases the boost when the engine hits about 2500-3000 Rpm .. I dont have a boost gauge, so i don't know how much psi the turbo hits

[GeeYou8]

You say that the valve opens at 2500 to 3000 RPM, is that under load or just revving in neutral?
When it sounds like a lorry is that exhaust noise or air coming out of the valve you mentioned?
A boost gauge will give a lot of answers.

[mudski]

Nissan call that valve a intake bypass valve. Its mounted in the intake manifold, not the turbo. ( if its the big round thing with the thread on it your talking about.) I would assume its just a pressure relief valve, so it opens up at a certain pressure to prevent over boosting of the motor.

[Kimbo63]

You are right westy a blow off valve is only needed if you have a throttle body between your turbo and intake so when you close throttle off the boost can escape

Nissanpatrol97
I think what you are referring to as your turbo is your manifold (has turbo written on it) the round thing on the manifold could be a blowoff valve or safety valve of some kind can you take a photo from the side need to see where your throttle cable connects to confirm

[Nissanpatrol97]

You say that the valve opens at 2500 to 3000 RPM, is that under load or just revving in neutral?
When it sounds like a lorry is that exhaust noise or air coming out of the valve you mentioned?
A boost gauge will give a lot of answers.

Only while i'm driving, not in neutral

[Nissanpatrol97]

You are right westy a blow off valve is only needed if you have a throttle body between your turbo and intake so when you close throttle off the boost can escape

Nissanpatrol97
I think what you are referring to as your turbo is your manifold (has turbo written on it) the round thing on the manifold could be a blowoff valve or safety valve of some kind can you take a photo from the side need to see where your throttle cable connects to confirm

Yes sorry, it's the manifold with turbo written on it :oops: I can take a photo saturday, i'm out offtown this week. The "valve" dumps air, when i'm driving, not in neutral, if I rev up. I do not put much pressure on the engine, whilst driving. Just speed up as normal, and when the revs hit 2500 it dumps air, and if ill keep on dumping when I'm accelerating.

[GeeYou8]

It sounds like the valve is opening when the turbo is producing boost, a boost gauge will tell you if it is opening at the wrong pressure.

[Kimbo63]

Sorry there mudski we must have been typing at the same time lol
I was just taking a long time getting my head around the question