What symptoms would a cracked manifold give.My car boosts well on full throttle ( which it never did before Bens remap ) but its fluctuating badly on light throttle? Changing the n75 to a n75j only made it worse and more and more recently it chuff when cold like and exhaust blow but i cant see it.Any ideas :wonder:

p.s 1.8t are the bain of my life...bring back my W8 :'(

I recently cured a boost fluctuation by servicing my Forge DV. Turns out it was caked in crap and sticking, causing an increase in hysteresis.

Exhaust blow sound could be the combi valve for the secondary air injection (it opens a port in the exhaust side of the head). Is it only on cold starts yeah?

Exhaust noise when cold is probably secondary air pump housing split. See here http://uk-mkivs.net/forums/t/141240.aspx

If you haven't already done it, try cleaning the throttle body.

DV was cleaned and regreased not long ago and yes the air pump is leaking so that must be the blowing sound cheers

maybe its bens map ????

call him he will know whats wrong im sure as another members car did the same when bens map was installed and was fine once removed

I have the sts so i could remove it and see.I think my car has an air leak somewhere since i bought it that no one can find

try it and see what happens

if it fine when its removed you know its the map if its still a problem then atleast you have ticked one of the boxes

I'll try it tomorrow and see.Only noticed it recently because im not driving it flat out anymore like i did for the 1st week after getting the map

my car had ben's map on it and it ran fine, my car sounds like its blowing but isnt and its only since i fitted the sports cat that it became noticeable i put it down to being a less restrictive system flowing more gases. i also think i've got an un detectable air leak somewhere and the only way i shall find it i think is by smoke testing it but again i've got no hesitation or fluctuating. have you had vag-com on it to see if there are any codes?

Edited 10 October, 201015 yr by sivrs

si i bet it leaking on the connection of the rear boost pipe to metal boost pipe that runs down the back of the engine

very very very very common they have changed the design of the seal as the old version is utter rubarb

si i bet it leaking on the connection of the rear boost pipe to metal boost pipe that runs down the back of the engine

very very very very common they have changed the design of the seal as the old version is utter rubarb

i'll have a look, but it still runs fine no probs at all. at least it'll keep me occupied at work

keep you away from the ps3 for an hour lol

when you look at the pipe if the is condensation around the oint then its leaking

keep you away from the ps3 for an hour lol

when you look at the pipe if the is condensation around the oint then its leaking

cool. and its at the bk of the engine not the ones on the top? that go to pcv/n75 etc?

the metal joiner hose that goes down the back of the engine from turbo to pancake pipe between the 2 hard pipes is a silicone pipe and its the joint onto the larger ipe that is crap you will understand when you look at it drivers side behind wheel

Why would the car behave great when the map was first put on then slowly get worse in regards to the light throttle boost fluctuation?Its always run on vpower and booster.

Why would the car behave great when the map was first put on then slowly get worse in regards to the light throttle boost fluctuation?Its always run on vpower and booster.

it could have high lighted a boost/vac leak that was there but wasnt noticeable. since your boosting higher there will be more pressure on the hoses

What about trying a spring with more pre-load in the DV?

The stardard green spring in the Forge valves is stated to operate within 5-15psi. My Shark stage 1 map peaks at 19psi, so yours must be similar.

Perhaps try the yellow spring (15-23psi). I'm thinking of trying one too. http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=200101&product=FMDVTUN

I'm thinking that your DV is opening on part throttle, causing the boost fluctuations.

Do you have a boost gauge? Do you know what it's peaking at? Same goes for you Si! Also how much is it fluctuating by?

What about trying a spring with more pre-load in the DV?

The stardard green spring in the Forge valves is stated to operate within 5-15psi. My Shark stage 1 map peaks at 19psi, so yours must be similar.

Perhaps try the yellow spring (15-23psi). I'm thinking of trying one too. http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=200101&product=FMDVTUN

I'm thinking that your DV is opening on part throttle, causing the boost fluctuations.

Do you have a boost gauge? Do you know what it's peaking at? Same goes for you Si! Also how much is it fluctuating by?

mines not fluctuating mate i get a cel now and again, ive checked all the hoses and found nothing it's only started happening tho since i put it bk to standard and took the map off (was going to sell it). after speaking to ben@shark i now think its to do with the SAI being removed as the map would have took it off! hopefully getting the map put bk on soon

even when i had the boost gauge in it boosted and held it fine both standard and with the map (god i miss stage 1 :'( )

Edited 13 October, 201015 yr by sivrs

even when i had the boost gauge in it boosted and held it fine both standard and with the map (god i miss stage 1 :'( )

Can you remember what it peaked at Si? Just to compare it to mine for information.

Mine is faultless too. Drives like a dream and goes like a rocket! Get the Shark stage 1 back on mate!

I don't think I could ever go back to less power now. The only way is up!

Can you remember what it peaked at Si? Just to compare it to mine for information.

Mine is faultless too. Drives like a dream and goes like a rocket! Get the Shark stage 1 back on mate!

I don't think I could ever go back to less power now. The only way is up!

mine used to peak at about 18-19 psi, i agree it went like stink, so i'm hoping to get it back on soon. the only thing i've not checked now come to think of it is the standard bosch dv i put bk on it. i can hear it slightly what with the drilled airbox so i assumed it's working ok?

si i bet it leaking on the connection of the rear boost pipe to metal boost pipe that runs down the back of the engine

very very very very common they have changed the design of the seal as the old version is utter rubarb

This is interesting I have noticed on mine there is a bit of clear water leaking down on sub frame could this be what it is????Is it a easy fix??

aircon drain....

What about trying a spring with more pre-load in the DV?

The stardard green spring in the Forge valves is stated to operate within 5-15psi. My Shark stage 1 map peaks at 19psi, so yours must be similar.

Perhaps try the yellow spring (15-23psi). I'm thinking of trying one too. http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=200101&product=FMDVTUN

I'm thinking that your DV is opening on part throttle, causing the boost fluctuations.

Do you have a boost gauge? Do you know what it's peaking at? Same goes for you Si! Also how much is it fluctuating by?

I have a bailey DV and i dont know what spring it has :no: It peaks at 22psi then settles to 20psi in 4th and 5th but in the other gears it goes to 15 the 12psi.A wee chat with ben confirmed this is because it has reached its "asked" target in these gears with less load.Under light throttle when lightly accelerating it goes from 5-7psi to 10-12psi in gentle pulses.Its really annoying and now my wife wont drive it :S ....is that a bad thing

Oh and its a stage 2 remap before you start worrying about the boost.

Cheers guys

Edited 13 October, 201015 yr by wagonwheels

aircon drain....

Well it drips all the time when I sit at idle and when car is shut off it is just to the right side of turbo looking from the front of car! it is clear water as I have tasted it ? Is the aircon drain there???

yes, it is, its on the bulkhead on the right hand side of the engine bay,hope it tasted nice :p