Re: 5KCSTQ Wastegate Springs

[Thomas Tornblom <Thomas.Tornblom@nexus.se>]

Dear List,

I got a spring from Bob Myers yesterday (thanks Bob!) that is
supposed to give around 2.5 ATA. The spring I had was supposed to give
around 1.8.

After feeding the kids, I sneaked out into the garage and installed
the new spring, anticipating the ride of the century ;-)

Imagine my disappointment when I tested it and there was absolutely no
change :-(

When I first installed the upgraded ECU and spring two years ago, I
got readings of 1.9 - 2.0 bar. After a short while I noticed some
rattle from the cat converter. We have a mandatory 80000 km/5 yrs cat
converter warranty in Sweden, and this was about to expire. I put the
old spring and the old prom back in and had the VAG shop check it out
when I was doing the regular service.

They said it was a heat shield that had come loose in the rear, and
they had welded it back on.

When I put the spring and the prom back I noticed that I could only
get 1.7 and occasionally 1.8 bar. I didn't care too much about this,
as I though this was more a problem with the gauge and I didn't notice
any substantial difference in performance.

This summer I had to replace the front crank seal. When I had all the
obscuring parts removed, I checked the turbo with my fingers. It felt
a bit sticky. It had no noticeable radial play, and about 1 - 2 mm
axial play. If I had it axially centered, it would spin very easy. If
I on the other hand moved it a bit off center it suddenly became very
sticky.

Can this be my problem? If so, what should I do, replace the turbo?
Can it be opened by a layman and cleaned? I can imagine the feeling
was due to soot on the axle. Pretty likely too me.

Can it be the cat converter that is clogged, or the rest of the
exhaust? The exhaust is in good shape otherwise. Somewhat likely.

ECU. Seems unlikely.

Air filter. Supposed to have been replaced just a month ago. Its so
damned hard to get at, that I haven't checked that it really was
replaced. Being hard to get at is perhaps just a reason to really
check?

It has no vacuum leaks that I'm aware of. The engine stalls if I pull
the dip stick when the engine is running.

I'm planning to test by removing and plugging all the hoses from the
WG to be sure it isn't something that opens the WG.

Can one connect a pressure gauge to the exhaust analyze pipe besides
the intake manifold and measure the back pressure, and if so, what
should I expect?

Oh, almost forgot. The car is a '90 100 tq, MC engine, runs on 98
octane unleaded. Was run on Castrol GT<something> dino-juice the first
45000 km:s. Has only had Mobil 1 synthetic since I layed my hands on
it. Has 95000 km on the clock.

Thomas

Real life:      Thomas Törnblom           Email:  Thomas.Tornblom@Nexus.SE
Snail mail:     Combitech Nexus AB        Phone:  +46 18 171814
                Box 857                   Fax:    +46 18 696516
                S - 751 08 Uppsala, Sweden

Unix is simple, but it takes a genius to understand its simplicity. -DMR