Leaking wastegate?

johnd · Post by **johnd** » Tue Nov 18, 2003 3:40 pm

Hi,

I was waiting for the tappet noise to go this morning (really must get some new shims!!) and pushed the accelerator upto about 200 revs whilst stationary. It was at this point I heard a high pressure air 'hiss'. I took my foot off the accelerator and it went. Back upto 2000 and it came back. Could the wastegate be venting as I was stationary or do you think the diaphragm may be leaking? It does seem a little lower on power recently and I'm sure the wastegate is original (car is 9 years old). Im gonna have a listen with the bonnet up in a bit and see if I can hear where it's coming from. If it is the diaphragm can these be bought separately as you can for standard dump valves?

Cheers

John

martinholmesuk · Post by **martinholmesuk** » Fri Dec 12, 2003 12:07 pm

or do you think the diaphragm may be leaking?

I would think it's this because it's sounding like a dump valve! Whats everyone else think?

Did you fix it?

volvofox · Post by **volvofox** » Sat Dec 13, 2003 12:24 am

what are waste gates for ... ?

Bakke · Post by **Bakke** » Sun Dec 14, 2003 8:05 pm

The wastegate is a valve in the turbo that opens when your turbo is making to much pressure. (the famous 0.7bar in the chip).
When the wastegate opens, it directs the exhaust gasses directly into the exhoust system while bypassing the turbo. Result: the turbo will slow down because it loses the exhaust flow end the pressure will go down. Normally a wastegate doesn't hiss. Even if it's open the air is bypassed inside the turbo. Your problem could be a breach in the turbo housing or one of the hoses. I have the problem myself. I found the leak, I only need the replace the hose

Bakke · Post by **Bakke** » Sun Dec 14, 2003 8:07 pm

I"ll try to post some pictures of the wastegate tomorrow

johnd · Post by **johnd** » Tue Dec 16, 2003 5:28 pm

Hi Bakke,

If you could post some info. that would be great. It seems to come and go on mine and ive only ever heard the venting sound shortly after startup. Getting a dump valve soon though so that should remedy the problem...if it is with the wastegate that is.

Cheers

John

pol · Post by **pol** » Tue Dec 16, 2003 5:44 pm

Follow the wide plastic / rubber tubing from the airbox / filter towards the back of the engine bay and down. About halfway down you'll find the existing re-circulating valve. It's black and has a vacuum hose attached to the top and another pipe to connect to some turbo stuff...

Just buy a dump valve and get it over with! You know you want to really.

pol

Bakke · Post by **Bakke** » Thu Dec 18, 2003 3:43 pm

Here are the pictures from the turbo with the wastegate inside

doug_480_turbo · Post by **doug_480_turbo** » Thu Dec 18, 2003 5:58 pm

johnd wrote:Hi Bakke,

If you could post some info. that would be great. It seems to come and go on mine and ive only ever heard the venting sound shortly after startup. Getting a dump valve soon though so that should remedy the problem...if it is with the wastegate that is.

Cheers

John

a waste gate and dump valve are 2 differant things. if the standard dump valve was leaking the pressure may not get high enough to open the wastegate. a dump just gets rid of pressure when you come off the gas.

dragon · Post by **dragon** » Thu Dec 18, 2003 9:21 pm

I suspect he meant MBC, which would bypass the gadget that opens the wategate at the set pressure, although if it's leaking, this wouldn't fix the problem, as pressure would still be being lost in the split (or whatever is wrong with it)

johnd · Post by **johnd** » Fri Dec 19, 2003 12:44 pm

Ive been going on about the wastegate here when I meant recirculating valve haven't I?????

DOH!

MatBat · Post by **MatBat** » Fri Dec 19, 2003 12:53 pm

johnd wrote:Ive been going on about the wastegate here when I meant recirculating valve haven't I?????

DOH!