im trying to hunt down a boost leak and thinking just maybe my Vacuum hose's from the turbo and actuator are to blame.
so going to order one blue and one red Silicone hose from ebay.

just wondering what size these hose's are?? thinking 3mm or 4mm?? no doubt this is an easy one for some of you guys

cheers

steve

I put 4mm ones on and they were the right size.

thanks matt. im surprised you still remember since selling your coupe

I can remember every aspect of that car like it was yesterday.

If you have leak on your actuator the boost will rise - most likely drastically.

ok thanks kj16v, if there was say a split in the hose coming from the actuator to the ebv would it still rise drastically??

if you want vacuum hose i have reel of blue 4mm - if your interested let me know how much your after.

Yes. The actuator is opened by boost air pressure from the inlet manifold. If there is a split in the tube feeding the actuator, the actuator won't er, actuate, hence the wastegate will stay closed. With the wastegate closed the turbo will spin out of control and go bang (well, hit the ignition cut-out in a Coupe).

thanks for the offer hyperlink but ive already ordered some of ebay before i read your post i'll know better next time

thanks kj16v, i didnt know that so i guess you really do learn something everyday. right now i al i need to is remember it..... i have a terrible memory!!!

Try replacing all the other vacuum hose at the back of the engine, and going to the DV. Do you get any strange noises when lifting off the throttle? (compressor surge)

are the vacuum hose's at the back of the engine easy to get to mat??? yes i do get a chatter if i lift of the throttle at low boost. around 0.2 bar on the gauge so very low boost. i was thinking maybe the spring is to hard in the dv, running a Bailey DV26. second hand so dont have the other springs to hand.

Sounds like a split hose to the DV then, that would cause your compressor surge as the DV wouldnt open. Alternatively it could be the short one on top of the engine that goes over the ICV to the FPR, that would be pretty easy to spot!

Do you have a boost gauge with a vac hose running into the car? If so (and you cant find a leak elsewhere), then pull it through and check the length of that for splits.

It would have to be a big split / leak to only give you 0.2 bar boost.

sorry matt i mean im not getting 0.2 bar on full throttle i get just below 0.8. i get the chatter sound if im driving around slowly, not using much boost, around 0.2 bar gives me a chatter sound.

i thought about the vac hose for my boost gauge leading into the car so decicided to change it as look abit worst for wear. but no luck still no change in boost

Oh I see, well a very slight drop in boost can be much harder to trace, and could be a lot more things causing it!

If it doesnt make the chatter at full boost throttle lift off then it wont be a split in that pipework.

If you cant find a leak you could have a stuck DV or wastegate that wont shut completely, or incorrectly adjusted actuator arm, or a cat/intercooler restriction, or a dodgy boost controller valve.... etc

i have a sneaky feeling its my cat as not long ago i had to get my turbo replaced. thanks for the advise matt. i'll let you know how i get on.