Subaru Enthusiasts Car Club of the Sierras - View Single Post

cody · 2009-06-01, 08:48 AM

It's just tapped. Can you just weld in a bung? Jeremy of Crucial Racing posted that you have to heat up cast iron to 500*F before you can weld on it. I didn't think that helacoil required any JB Weld type stuff. I actually considered JB Weld, but at least the "Quick" version I have says it's only good to 300*F. No good.

In the interest of saving me from typing two updates, here's the latest update I just typed on WRXFanatics:

Quote:

name='EJ20Legacy' date='May 31 2009, 05:08 PM' post='841585'
Wow why did you have it in and out so many times?

If the probe works, I'd just leave it and not touch it. If it's faulty and you have to replace it, then I'd try and get an adaptor that is 1/8 NPT (1/8-27 tapered pipe) on the inside for the new probe and something larger on the outside that you can drill and tap the manifold for. Or, you could make an adapter by using a short bolt like you suggested and drilling a hole in the center of the bolt and tapping that for the probe. 11/32" drill bit for a 1/8 NPT tap, FYI.

Welding on cast iron is kind of a biotch. The shop would have to remove it from the car and put it in an oven to bring it up to a good 500+ degrees, then weld it.

OH!!! If it's a passenger side manifold elbow (frankly, your tap should be on the driver side one because cylinder 4 tends to run the hottest and often #2 is right behind it) I think I have an extra one here that you can purchase on the cheap. I may even be tapped. I know it's P&P&C. Basically, somehow a driver side elbow got lost and I've had this extra passenger side one for years with no mate

Jeremy

I've had it out so many times over the years because it has to come out any time I remove the heat shield to get to various pre-turbo leaks I've had. Once I got all OEM gaskets back in, I thought I'd be good, but the stupid UP to Ex. Man. gasket started leaking again so I took the heat shield off to diagnose if that's where it was really leaking and when I saw that it was, I didn't have a new gasket so I simply tightened the bolts which cured it for a few months but the leak, unsurprisingly, came back so this weekend, I put in a Grimmspeed gasket since they come highly recommended and Ed gave it to me last time he was up. They're basically OEM but a touch thicker. This time I loosened all of the bolts I could get to for the UP to Turbo connection and the bolts that secure the turbo in place. That got me a touch of play, but not as much as I expected. I guess there were some bolts that I couldn't get to but it did allow the UP to flex a bit. I also loosened the Ex. Man. to head bolts. Then I put in the new gasket and torqued it down as hard as I could with box end wrenches and a rubber mallet. Then I retightened the Ex. Man. to head, then tightened up the UP to Turbo bolts, and lastly the turbo bracket bolts. This is the order I’ve seen recommended in a few places.

So that leak is now fixed. No more rape whistle turbo noise and my boost response is noticeably better. I really don't want to take it all apart ever again, but the EGT probe is still leaking. And no, it doesn't work. I'm 80% sure I just need a new probe but it could be a problem with the gauge or the wiring.

So, yesterday, in an attempt to fix the issue, I looked for a helacoil at Kragen and True Value but neither had one in the correct size for the probe so I may just drill it out to the next largest size and plug it with a bolt since it doesn’t work and it’s in the wrong header anyway.

What I ended up doing as a temporary fix is I used this Screw Hole Repair stuff I had picked up at Harbor Freight a while back. It’s just thin sheet metal that you cut into strips and put into the hole to act as a shim. I experimented with it to ensure it held up to the screwing back in process and it seemed to. But I couldn’t get the hole to seal completely and pass the soapy water test.

I’m tempted to just leave it since I really don’t think it’s losing much exhaust, but I won’t be happy with that. What if it blows the probe out at an autocross or somewhere else because the hole repair metal just melts…or whatever.

What sucks is that you’re supposed to remove the Ex. Man. Before you drill and tap it since any tiny metal fragments that you leave in there could destroy the turbo. But I’m tempted to just tap the hole with it on the car. The casting button I’d be tapping is on the bottom side of the Ex. Man. and the metal fragments are magnetic so theoretically between a magnetized screwdriver (with extra magnets attached to it for good measure) and a vacuum, I should be able to clean them all out and then just plug it with a bolt. If I destroy my turbo, I have another one I bought used for $100 shipped with only 10K miles of stock boost on it so it’s basically new, and how much longer can my current turbo with 102K miles on it (much of them at max boost of 16-17 PSI and lots of autocross and spirited driving…) really last?
That sucks that you can't weld on cast iron without removing it. I still wish I could just score a bolt that's slightly oversized to plug it. I think I'll call our local fastener shop which has awesome hardware and see what they suggest.

Jeremy, please go ahead and PM me a price for that replacement passenger side manifold, but is there any danger to running only one PP&C'd manifold? I'm guessing no.

http://www.wrxfanatics.com/index.php?showtopic=60022