www.gt4dc.co.uk
http://www.gt4dc.co.uk/forum/

What can be done about a sticky wastegate actuator?
http://www.gt4dc.co.uk/forum/viewtopic.php?f=2&t=267		 Page 1 of 1
Author:  Candyman [ Mon Nov 14, 2005 2:14 am ]
Post subject:  What can be done about a sticky wastegate actuator?
I am now 99% certain that this is the cause of my peculiar boost behaviour.

I was on the way home tonight and when I first floored it after the engine had had time to warm up I got runaway boost (it got to 1.35bar before i noticed what was happening and lifted off)

This happened with the ebc in high and low modes (1.15 and 0.9). By the time i thought to turn the EBC and see what happened then the car was behaving again. This means i can'r rule out for certain that the EBC is having a strop. I think it's unlikely though.

If it is a sticky actuator what can I do about it? Is it something that I can clean, lubricate or replace cheaply/easily? It seems to be something that eases off as the engine bay gets hotter but I'd rather not have the issue at all.
Author:  Loosey [ Mon Nov 14, 2005 8:39 am ]
Post subject: 
Paul,

AFAIK stock actuators are not serviceable items.

I had the diaphragm on Penny's split. This meant it had erratic boost but more problems holding boost than spiking.

My vote goes with the Forge actuator, it is adjustable, serviceable and more importantly, SHINEY!
Author:  **BETSY** [ Mon Nov 14, 2005 8:46 am ]
Post subject: 
Paul, sounds to me more like these very cold nights and gain setting to high on the EBC cauising the over boost.
Author:  Candyman [ Mon Nov 14, 2005 11:24 am ]
Post subject: 
Loosey, Shiney!? Why didn't you say so earlier? The decision is made :lol:
When it behaves it holds rock solid boost at any rpm so I am happy with the ebc settings I am running.

Steve, I hear what your saying but to go from 0.9 to 1.35plus from coldness is a touch dramatic isn't it?

It made 1.35 at 3500rpm so it wasn't from ragging it either.

I think I'm gonna wait a while and keep an eye on it to see how often it happens and under what circumstances.
Author:  Kris [ Mon Nov 14, 2005 1:37 pm ]
Post subject: 
Paul - have you disconnected the EBC and just run the stock setup? This might help to identify the cause of the problem?

Do you have a big exhaust? A hybrid turbo? What EBC have you got fitted?

Also, you might want to try blowing into the actuator hose and ensure it does not allow air to escape - might identify a split actuator diaphragm, (don't forget to block the other outlet that goes to the TVSV unit)

HTH :)
Author:  Candyman [ Mon Nov 14, 2005 2:38 pm ]
Post subject: 
I did try turning off the EBC but it was lat and dark and cold so that was as far as i got. It ran the normal actuator boost but when I turned the EBC back on it behaved so maybe the intermittent problem just happened to go away at the same time.

I have stock turbo, 2.75" exhaust and cat in place. I did a power run at Interpro earlier in the day and it behaved right through the rev range

EBC is GReddy profec B-spec 2

If the daiphragm is split I wouldn't have thought it would be possible to get an intermittent problem. Especially when the boost is so solid while it behaves.
Author:  Diceman [ Mon Nov 14, 2005 2:49 pm ]
Post subject: 
Hi,
Have you got a filter in the vac line to the EBC? They can sometimes get clogged with oil mist and stick as a result. Worth replacing lines and cleaning out if no filter is in teh system (oh and put a filter in!)
Author:  Candyman [ Tue Nov 15, 2005 2:23 am ]
Post subject: 
Filter is in place.

Right. It seems I may have been a bit premature in my yelp for help :oops:

Driving in the daytime today I had not one hint of this problem. But it came back on the way home from the pub earlier.

Having had more time to check what is going on there seems to be no problem with the EBC turned off. When it is on the boost is higher than I want by between 0.1 and 0.2 bar until I have been driving for quite a long way. After this it settles down to the levels I preset.

I guess this is down to the "set" and "gain" settings I have specified but I am going to stick with what I have chosen because I lose boost at high rpm if I set the gain any lower.

I can't remember the reasons right now but iirc you tend to get higher boost with colder charge temps. I reckon what is happening is this: I am giving the water and oil enough time to warm up but the turbo takes a while longer to get to full running temp because I have not given it any positive boost yet. This means the charge temps are far lower than they were when I set up the EBC and this gives different boost levels.

My plan to deal with this is to give the car longer to warm up before I give it hell. Nothing more, nothing less.

Feel free to shoot me down in flames if you disagree with anything I have said :wink:
Author:  **BETSY** [ Tue Nov 15, 2005 8:51 am ]
Post subject: 
Paul, its a common problem with the colder temps found at this time of year.
Usually you can get over boost on the first few WOT applications and once the charge cooler has a little heat in it things tend to settle down.
If you have a EBC with various settings I would have a setting with a slightly lower gain control for the evening drive :-)
Author:  Candyman [ Tue Nov 15, 2005 11:55 am ]
Post subject: 
I just have the two settings. Hi and Low

Low setting doesn't get into dangerous territory at any time of day so I just need to be sensible.
Page 1 of 1 All times are UTC + 1 hour
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/