View Full Version : Wastegate jamming open

2nd March 2004, 23:09
Just did a trackday on Sunday at Knockhill to try out my new Mods, a full de-cat using a Magnex twin-port DP, P1 centre and scoobysport BB, TEK 2.5 and a pipercross panel filter. Car ran fine for a lot of laps (coming in and out to cool the brakes) then suddenly lost boost after about 10 laps out(very hot). No CEL but when I checked the turbo the wastegate was open at idle. It stayed this way when it turned off also making me belive it was a jammed wastegate. This turned out to be the problem. I separated the wastegate from the actuator but it felt free (cue burnt fingers! ) and the actuator popped back in as it should do. I freed everything up and put it back together and went back out on track and had the same problem after 4 laps. Freed it off again but found that if I tapped the actuator arm back down on to the wastegate spindle it suddenly closed again. Problem kept returning when the car was getting hot.

I've posted this on SN and had a reply from Harvey, just wondering if anybody else has experienced this and if anybody has a spare TD04 I could rob some bits from?

Thanks Jamie

3rd March 2004, 00:37
have you increased the preload on the actuator at all?

3rd March 2004, 01:37
Jamie - I have a spare TD04 you can borrow some bits from to see what is the problem with yours.

Call me on 01224 749972 and we'll arrang efor you to come round one evening and we'll see what we can do!


3rd March 2004, 17:17
Haven't done anything to the actuator or the turbo John, just the above mentioned mods.

Russell, that would be great, I take it thats an Aberdeen No. mate. I'm in Elgin through the week so meeting you shouldn't be a problem.

Thanks Jamie.

3rd March 2004, 18:22
ok, just a thought. I have seen waste gate shafts bend when they are over tensioned and then get very hot on track, they literally twist due to the preload and heat.

3rd March 2004, 18:26
another thought, maybe your EGT's are going through the roof because its running lean? this could generate enough heat to bugger the waste gate shaft too.

If i were you i would do an ECU reset and if it starts running lumpy change the MAF sensor. Is this a 99/00?

3rd March 2004, 22:40
John, I only just fitted the ECU about two weeks ago. When I did it ran lumpy, so changed the MAF as soon as I could and it ran fine. The car is a MY00 UK. Spoke to Russell earlier tonight and we had a little chat about it. I'm going to change the actuator on his advice. It runs fine on the road but I wouldn't mind seeing if it is running lean. The better fuel consumption its getting is making me think. Could the Lambda cause lean running at high engine loads?

3rd March 2004, 23:16
Lambda sensor is ignored on full load, which is why the MAF is so important.

Reset the ECU, its not uncommon for new MAF's to fail within 2 weeks!

3rd March 2004, 23:20
oh, and throw away the pipercross filter, they are not a good idea on the MY99/00. Install a genuine STi panel filter, good for over 350BHP.

3rd March 2004, 23:55
I thought that about the lamda. I will try a reset tomorrow, see how I get on.


4th March 2004, 00:18
good luck jamie

4th March 2004, 06:21
I've not heard of a single 'green-spot' MAF failling?


4th March 2004, 10:19
Jamie : Did you get my post ?

4th March 2004, 17:13
No Harvey I don't think I did or did you mean the one on Scoobynet?

4th March 2004, 18:08
ECU reset done! Everything is fine, idle steady. Carried out the diagnostic check (connecting the plugs under the dash) everything fine. Next step actuator change, I'll do it next week when I get a chance.

Thanks guys, Jamie

4th March 2004, 23:58
I had an experience that may have been similar.
The W.G. was always slightly open even after setting it up properly. This happened several times. In the end I found this was because the turbo captive bolts were not tightened properly after I had clocked the turbo to ease installation.
I only found this after the WG spindle to the penny valve had been twisted with the heat and pressure on it. If your spindle has been twisted then I expect there has been excess heat so get the AFRs checked asap.