Leaking TiAl wastegate? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 01-04-2007, 04:55 AM   #1
Newb
Thread Starter
 
Join Date: Jun 2005
Location: UK
Posts: 17
Total Cats: 0
Default Leaking TiAl wastegate?

I'm using a TiAl 38mm external wastegate and noticed it was leaking exhaust gas the other morning. What I found surprising was that it was leaking from the flange at the exit side of the wastegate, so that means the wastegate leaks exhaust gas passed it at idle. Does anyone know if this is normal? If it leaks at idle, how much does it leak under boost???

Rich
Rich is offline   Reply With Quote
Old 01-04-2007, 05:55 AM   #2
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

Your wastegate should be fully closed at idle if I'm right.
When in boost it won't be leaking but it will be wide open allowing exhaust to flow through it. That's how it regulates boost, it relieves pressure, thus allowing the turbo to only spool to a certain PSI.
That is a pretty lamon explanation but I think it's right.
I think Tials can be rebuilt??
cjernigan is offline   Reply With Quote
Old 01-04-2007, 08:54 AM   #3
Newb
Thread Starter
 
Join Date: Jun 2005
Location: UK
Posts: 17
Total Cats: 0
Default

It's working correctly, my local dyno operator commented on the absolutley perfect flat-line boost control recently. But like I say, it's leaking at idle, enough for me to feel the exhaust gas coming out and see some condensation around the flange at start-up. I'll remove it this weekend when I fix the leaking flange and check it looks OK inside. It was brand new when the kit went on about 1K miles ago so I hope it doesn't need a rebuild

Rich
Rich is offline   Reply With Quote
Old 01-04-2007, 10:25 AM   #4
Senior Member
iTrader: (6)
 
Join Date: Mar 2005
Location: Sammamish, Washington
Posts: 1,396
Total Cats: 0
Default

The Tial is really easy to take apart for inspection although I have never seen one fail. Are you sure its a real Tial and not an Ebay knockoff?
Kelly is offline   Reply With Quote
Old 01-04-2007, 02:32 PM   #5
hrk
Junior Member
iTrader: (6)
 
Join Date: Oct 2005
Location: Atlanta GA
Posts: 335
Total Cats: 2
Default

Does your wastegate vent into atmosphere?
If it connects back to exhaust before any restrictions (catalytic converter, muffler) could it be just the seal on wastegate exhaust side is leaking the normal exhaust backpressure?

hrk
hrk is offline   Reply With Quote
Old 01-05-2007, 04:44 AM   #6
Newb
Thread Starter
 
Join Date: Jun 2005
Location: UK
Posts: 17
Total Cats: 0
Default

It was bought from Ebay, but listed as a "real" one, not a kncok-off. The seller seems to sell a lot of them and has 100% +ve feedback, I hope he hasn't ripped me off!

hrk - the wastegate dump pipe connects back into the main down pipe before the cat. So you might be right about it being normal backpressure leaking up the dump pipe. I'll check it this weekend when I remove it.

Thanks for the help guys.

Rich
Rich is offline   Reply With Quote
Old 01-21-2007, 12:00 PM   #7
Newb
Thread Starter
 
Join Date: Jun 2005
Location: UK
Posts: 17
Total Cats: 0
Default Update: fixed

Thought I'd post an update on this. I took the wastegate off and cleaned everything, then realised that I'd been running it without the valve seat

It doesn't leak any more, plus I get full boost 900rpm sooner, so I'm happy. There's a pretty obvious moral to this story!

Cheers,
Rich.
Rich is offline   Reply With Quote
Old 01-21-2007, 03:52 PM   #8
Senior Member
 
Join Date: Jan 2005
Posts: 737
Total Cats: 0
Default

Quote:
Originally Posted by Rich View Post
Thought I'd post an update on this. I took the wastegate off and cleaned everything, then realised that I'd been running it without the valve seat

It doesn't leak any more, plus I get full boost 900rpm sooner, so I'm happy. There's a pretty obvious moral to this story!

Cheers,
Rich.
LOL, I was gonna say that until I read this post
F20turbo is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM
3rd Time's a Charm...hopefully. zephyrusaurai Meet and Greet 2 09-28-2015 11:59 PM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:55 PM.