Wastegate Jammed Open?

[ian_jemo]

Hi all

Just wondered if there was a way to check if the wastegate was jammed open?

Still got my 5psi boost problem thought I better check it

Thanks

Ian

[jameswkr]

Ian. If you really want to check it, undo the 6 little nuts holding the WG top on ( mind the spring pressure as you come to the last turns ( undo them evenly ). You can then pull the bolt in the middle of the diaphragm up - it should move easily and drop back if released.
Your symtom suggests its the WGFV - approx .4 bar boost is how it will run disconnected ( or broken ). Run the tests as per S2 Central....Easy and relatively cheap to replace.

[ian_jemo]

Thanks I'll check it.

Already changed the WGFV, MTFS, MAF, Knock Sensors but still no difference.

[ian_jemo]

Is this also where you check the wastegate Diaphragm?

Thanks

Ian

[S2central.net]

Good tip from James there...

@Ian - did you reset the ECU after renewing all those sensors ? If not, just pull the ECU fuses for a minute or two (to empty its memory) then replace them. This puts ECU into a mode where it has to learn everything from scratch and it re-adapts to sensor inputs etc etc

You really need to do an output test to make sure that your ECU is talking to the WGFV. Easy with VAG-COM but can also be trigged from the OBD plugs as per blink codes. There is a trick for that, not documented on S2central yet, but look at www.sjmautotechnik.com for a how-to on that.

The WGFV makes a very obvious click-clack during the o/p test sequence.

[S2central.net]

Here it is - http://www.sjmautotechnik.com/troubl...20v.html#outs4

[S2central.net]

I'll have to update S2central.net with this trick - its one I haven't forget about when yu have VAGCOM available !


Paul

[ian_jemo]

Yep I did reset the ECU but no change.

Looks like my weekend is fully booked

Thanks for the info Paul

[UrS4boy]

I don't know if this will help or not since I have an AAN (like the ABY) not a 3B BUT....

With the early UrS4's, the boost signal hose from the intake manifold to the ECU goes through a moisture trap (looks like a black 35 mm film can with inlet and outlet nipples). It is very common that the OE hose clamps get weak and do not hold the hoses tight on the moisture trap. The result is the ECU never sees much for boost because of the leak. The worst case is the hose gets blown right off and the ECU only ever sees atmospheric pressure (zero boost). The cure is two small gear clamps, cost about US$1. (50 p).

Check your boost hose to the ECU.

Dave F.