Whats Going On With My Dump Valve ?

[stevie 4]

can anyone tell me from this wee vid whats going on with my dump valve you can see the gate opening but im getting no dumping.

any help would be apreciated and oh yea it has the blue spring fitted

just click the pick

[Big 'D']

Does it dump whilst you are driving, you dont really generate any +ive pressure in the manifold whilst reving stationary.

The piston you can see moving there is the main piston, there should also be a secondary piston which keeps the DV closed off with the engine at idle vaccum.

Cheers Iain

[stevie 4]

no it dosent ump while driving if you hold the accelarator that gate is closed.when i had it open there was a spring gate blue spring setup inside

[Big 'D']

no it dosent ump while driving if you hold the accelarator that gate is closed.when i had it open there was a spring gate blue spring setup inside

Was there only one piston inside when you had it open?

Cheers Iain

[stevie 4]

i take it there should be two?yes only one

[Big 'D']

i take it there should be two?yes only one

Ideally there should be 2. I think what may be happening is that even though the piston is moving to the closed position whilst you accelerate the boost pressure is leaking past the piston, do you have a boost gauge fitted and can you hear a hissing sound from the engine bay whilst the turbo is spooling?

Cheers Iain

[stevie 4]

No boost gauge but I was told yesterday that my car was whistling as I pulled into a car park

I have taken the valve off now just so I don't do any damage

[StewartyBoy]

Stating the obvious here, but no dumoing = no pressure buildup so I would be inclined to agree with the above. Somethings leaking for sure!

[stevie 4]

I can get hold of a spare spring so I'm going to try that as the gate is open on idle so I can only think that the spring is not doing it's job

[Big 'D']

I can get hold of a spare spring so I'm going to try that as the gate is open on idle so I can only think that the spring is not doing it's job

Seeing that the gate is open whilst you are at idle backs up what I said about a 2 piston DV, in the idle position the main piston floats in the mid position whilst the 2nd piston keeps the intercooler side sealed off. I think the spare spring will make no difference, you need to change your DV to a decent 2 piston one or the factory recirc, if you want a good 2 piston DV Forge do a good selection, if the one you have fitted is a Forge (cant tell from the vid) then it should really have a 2nd plastic piston and small spring.

Cheers Iain

[stevie 4]

all fixed now gave it a good clean as it was really dirty inside and it now works perfect yay

[lupuss]

If it's a Forge dump valve - looks like one... Send them an email or a phone call and ask about their servicing kit.

I bought one from Fleebay and found that it was sticking early in the morning and took a couple of hard accelerates to free up properly... I could tell since no dump and turbo flutter..

I took it appart and the lower piston had dirt that seemed to cause it to 'stick' to the intercooler exit hole.

Cleaning that part with brake cleaner removed the build up and it worked fine.

I then contacted Forge about what type of grease I should use, and they sent me a free servicing kit which had new grease, rubber gasket rings, new lower spring and alloy piston... I cleaned the valve up, installed new parts, regreased and the dump valve now works beautifully.

Excellent customer service from Forge!

Hope that helps,

lup.