VWDiesel.net The IDI, TDI, and mTDI source.

Engine Specific Info and Questions => IDI Engine => Topic started by: Rabbit TD on December 11, 2010, 04:56:00 pm

Title: T-3 Wastegate valve seat cracked (Fixable?)
Post by: Rabbit TD on December 11, 2010, 04:56:00 pm
  I had some time today so I thought I would tear down a rebuilt T-3 turbo I bought a few years ago that never really put out much boost.  Just as I suspected during the rebuild he didn't lap the valve for the wastegate as it has one of those canister type actuators on it you can't get apart to remove the valve.  I got it apart today and was gonna lap the valve and just leave it disabled like the one I've been using which works fine this way, I only run about 15  psi. max anyway.  After I cleaned it up real good before I lapped it I noticed the valve had been leaking and there are 2 hairline cracks radiating out from the seat area letting the valve leak and has the valve eroded in those areas a little.  I'm wondering if a machine shop can possibly machine that area and install a valve seat to at least let the valve be able to seal or even weld or seal the whole area up somehow as I won't be needing the wastegate anyway.  I know that doesn't elimiate the cracks beyond the seat but it doesn't look like they go much further than a seat would anyway and it looks like it's just leaking in the valve contact area.  They could put any valve in there as far as that goes if they don't have a seat the right size for the existing valve as it wil remain closed anyway.  Has anyone else tried to save a t-3 or other turbo doing something like this or by some other method?  I'd really like to save this turbo if possible. I even thought about running a weld bead around the valve and the seat if it's possible ???
Title: Re: T-3 Wastegate valve seat cracked (Fixable?)
Post by: Rabbit TD on December 12, 2010, 02:22:34 pm
Somebody please give me your thought ???
Title: Re: T-3 Wastegate valve seat cracked (Fixable?)
Post by: R.O.R-2.0 on December 12, 2010, 04:14:53 pm
weld up the cracks, and then weld the wastegate closed..
Title: Re: T-3 Wastegate valve seat cracked (Fixable?)
Post by: Rabbit TD on December 12, 2010, 08:18:55 pm
weld up the cracks, and then weld the wastegate closed..


That really sounds like the easiest thing to do I think also.  I just wonder how hard it would be to weld the valve face which is made out of who knows what kind of steel to the seat area of the casting which as far as I know is cast iron , no separate seat just machined for the valve.  But it sounds like the easiest solution to me too if it can be done without cracking the casting even more.  Guess I'll take it to the shop and see what they think, no way I'm gonna try to weld it myself :-\  I just thought about something after I posted this.  I wonder if that valve is sodium filled,  I'm pretty sure they can't be welded from what I've heard but I don't know if that's true or not.