How to find boost leak?

[bobski1]

I have a VW golf mk5 GTi, manual, which is suffering from the following errors:

004917 - Engine Torque Monitor 2, P1335 - 008 - Control Limit Exceeded - Intermittent
000136 - Fuel Rail/System Pressure, P0088 - 001 - Too High - Intermittent

The fuel system being too high I think will be a new HPFP however the torque monitor from the OBD reader seems to indicate excess air in the system. My plan is to unplug the MAF sensor to see if it runs smoother and checks some logs.

Next is to check for boost leaks or excess air coming into the system. Wondering how people do it via home mechanics? I can get my hands on some leak detector spray but if it's under vacuum then will it work or do I need to find a smoke machine of some type?

[GreenV8S]

Leaks in sections that see manifold depression can be found by spraying carb cleaner on the outside and seeing whether the revs pick up. A smoke generator would show leaks anywhere but you still need eyes on it.

[ssray]

I tried the DIY smoke generator route, I failed...
I took each hose off and inspected it.
The local turbo place charges £25 for the smoke test

[stevieturbo]

Usually easiest way, is to look at the hoses. In almost all cases you can see where there is a problem without resorting to any fancy means.

[bobski1]

stevieturbo said:

Usually easiest way, is to look at the hoses. In almost all cases you can see where there is a problem without resorting to any fancy means.

Plan to run the car without the MAF plugged in to see if it runs smoother and check the fuel trims. Weather is better today so I can get started and try to find the damaged hose. The only silicone bit is an elbow from the cone filter but I need to check it all. Horror stories of cracked turbos giving me the sweats

[aka_kerrly]

The Ross Tech site can be helpful with VW error codes, gives you a few pointers/ things to check.

http://wiki.ross-tech.com/wiki/index.php/17743/P13...

[Steve H]

bobski1 said:

Plan to run the car without the MAF plugged in to see if it runs smoother and check the fuel trims. Weather is better today so I can get started and try to find the damaged hose. The only silicone bit is an elbow from the cone filter but I need to check it all. Horror stories of cracked turbos giving me the sweats

There’s a good chance it will not still operate fuel trims with the MAF disconnected and even if it does you will be looking at its attempt to compensate fueling against guesswork of the quantities of air in the system.

If you have a recurring fuel pressure problem I’d suggest that needs sorting first of all.

[bobski1]

Did one run with the MAF and another without. Ran much the same. Found the boost leak however one of the metal collars on the hose had cracked through so was out.

Diverter valve was the next failure point and has been changed too.

Fixed this and now onto the wastegate/vac line issue.