Boost leak found!

[Anders_WR1]

I've found a boost leak at last. I came up with a contraption for testing pressure in the FMIC pipework without the engine running...

I used the hose from a brake bleading kit that's powered from the spare tyre air pressure, then pushed one end through a hole I drilled in a small plastic disc. I used araldite to seal the plastic disc to the hose from the brake kit.

The plastic disc was small enough to fit down the FMIC pipework on the pressurised side of the turbo. I taped this lot in place creating a seal on the plastic disc. I pulled off the silicon hose by the throttle body and taped up the FMIC pipe to seal that end up. So I had a seal at the FMIC pipework by the turbo end and the throttle body end.

I connected the spare tyre to pressurise and I could hear a small leak. I tracked it down to a small gap between the dump valve and the adapter plate that had been fitted to keep the standard re-circ dump valve.

I'm going to order a couple of new gaskets tomorrow and see how I get on. I'm also going to try taking the boost readings for the Defi's from the manifold, rather than the vacum pipe that goes to the dump valve to see if the readings are different.

I know a picture would be easier, but my camera phone is fooked!

Anders

[WR1 Bro]

Great work Anders... but wasted on most of us... Keep us informed though.

[marky mark]

Impressive Fault finding Anders.

[Anders_WR1]

I pulled off the dump valve and FMIC adapter flange today. I cleaned up the mating surfaces and checked to see how flat they were. The adapter flange was not perfectly flat.

I got two gaskets from the dealer, but when I fitted one it seemed to fill the gap ok (I also used Hylomar gasket sealant). So I thought I had it cracked...but when I went for a test drive the noise is still there . The noise sounds exactly the same, so although I've found and fixed one leak there's another somewhere.

The dump valve's got to be on the list now. Does anyone have a spare standard STI dump valve? I know a few people have VTA's fitted now.

One of the lads who comes out cruising with us has a Forge VTA fitted. I might ask him if I can borrow his for a quick run.

I also plumbed in the Defi boost sensor directly on to the manifold using the same place as WRC Tech used. I went for a run and the boost was being reported 1.5 BAR on full chat, which is the same boost figure I was getting using the vacum pipe that goes to the dump valve.

I did notice the gauge was bouncing around by about 0.1 BAR, but I think that might be caused by the turbo surging. So it looks like either my Defi boost sensor is fooked, or WRC readings of 1.1 BAR were screwed.

I'll re-inflate my spare tyre tomorrow with exactly 1.4 BAR pressure, then I'll connect the brake bleeder hose to the tyre and the other end to the Defi Boost sensor. If I get 1.4/1.5 BAR I'll know the sensor is ok.

Anders

[SPIKE LIKE MIKE]

Top man.....I would of given up on line 1 an dtakein it to a garage

I suppose the beauty of doing stuff like this yourself is you ge an understanding of the workings instead of just handing over

[Anders_WR1]

[quote="Spike "THE LEGEND" Mike XXX"]Top man.....I would of given up on line 1 an dtakein it to a garage

I suppose the beauty of doing stuff like this yourself is you ge an understanding of the workings instead of just handing over

[Houdini]

That's great work, Anders. In fact, it's quite humbling. It all went a bit over my head (which is not hard) but I really enjoyed this post