Definitive method to test boost leak?
 

Hi

im sick of the whistling leak noise out of my car. I've got to find the leak.

Ive got a kit for attaching to the inlet pipe

so which hoses needs blanking ?

should intercooler and inlet manifold be included in test?

thanks

A smoke test would reveal any leaks

Thanks but I've not got a smoke tester

i really need to know what parts to test and which hoses or ends to blank?

cheers

Can't help you with the test but my money would be on the uppipe or uppipe gasket causing the whistle.
Have you check out the exhaust system for leaks?

How do I check for leaks on uppipe gaskets?

Get your head under the car and check for signs of it blowing,you should see black soot around the flange if it is.

There'll be 2 systems that most likely make a whistling leak noise, intake or exhaust. I've experienced issues with both on my car.

A boost leak on the post turbo intake will most likely sound more like a wailing banshee, and could be easily reproduced by flooring it during cruise, so that you get the boost pressure at lowish rpms. On my car it actually popped the bonnet up onto it's secondary release, presumably because of the increased pressure in the engine bay (I was blo*dy surprised when that happened :eek:). The leak was at the hose between the intercooler and the throttle body as the hose clamp was not tight enough and on the p*ss, so part of the hose had pulled out. There was evidence of fresh oil blasted on the throttle body also, so it was pretty obvious.

A vacuum leak on the pre turbo side would sound like a deeper whistle or whine. I had this when the (stock) air filter box housing tabs broke and it was drawing air through the side of the box.

An exhaust leak up to and around the turbo, on mine at least, sounded more like slightly deeper screaming from under the bonnet from about 4k rpm and above, and eventually I started getting exhaust fumes in the cabin which progressively got worse. In my case it was the gasket between the turbo and the downpipe that was shot, but it could be upipe gaskets as mentioned. However, there was no evidence of soot or blackening and it could only be seen by taking off the downpipe.

If the exhaust leak is from under the car you will most likely hear it when idling and be able to feel the warm gases if you jack the car up and check the joints.

In any case, for the inspection, work backwards from the components that were changed or disturbed most recently.

That's mega helpful

its a whine type sound I've got

not an exhaust blowing type sound. I'm pretty sure No noises when idling

thanks

Hi

am i being daft here?

im having another go at trying to find this leak now

ive got airline connected, hoses blanked on inlet but turbo side to intercooler open.

Cant hold pressure at all on inlet. Sounds likes its losing pressure at turbo

whats the actual correct method method of testing?

cheers

Put a vacuum cleaner in reverse up the tailpipe (or an air line if you have that). There's no engine noise so it's really easy to find leaks. I guess that should go beyond the turbo into the cylinders so might help find a boost leak too if it's not pre-cylinder. Help to narrow it down anyway.