pinhole leak in header collector

[ReMorton]

Found a pinhole exhaust leak at left side header junction with front of collector. Looks like exhaust piping from cylinders 5 and 6. Header system is 'jet coated'. In the interest of protecting the appearance of the coating, before I turn the car over to 'Mr Welder' to close the leak, any suggestions.
Thx
Bob

[bobcowan]

You can't. The coating needs to be removed it can be welded.

As a temp fix, you could cover the hole with lab metal or muffler putty, then spray paint with silver BBQ paint. You can see the repair if you look close, but otherwise it would be pretty invisable.

[ReMorton]

Thx. Will give it a shot and see what happens..

[Learjockey1]

You can also try the ultra hight temp silicone sealer, the orange stuff. I read it wil stop
1/8" header leak at the heads.

[bobcowan]

Originally Posted by Learjockey1

You can also try the ultra hight temp silicone sealer, the orange stuff. I read it wil stop
1/8" header leak at the heads.

Yes, it will. At the header flange. I havn't used a gasket there in years - silicone only. But, it has no structural strength. If you put it over a hole, it will blow out on the first drive. If you're lucky and carefull, it might last 5 minutes. Maybe.

[Tim Brewer]

It's really hard to fix a pinhole, the inside of the area around the pinhole is probably rusted too thin to weld shut. You may have to have a larger patch cut out and replaced and then the you'll have to have your whole pipe stripped and recoated. Annother thing to think about is if you had one weak area, there's a good chance you may have annother one as well that could pop up after all your repair work is compleated. So, if the pinhole is in the collector, you might consider changing out the collector to avoid doing a second repair down the road.

[cobraman428]

Yep, been through this too. Didn't notice it until car was assembled with freshly coated ceramic sidepipes. Mine leaked at the sidepipe where the 4 pipes reduced to one at the collector. I removed the sidepipe from the car. Stood the sidepipe vertically and took some masking tape to prevent leakage and used the orange high temp gasket maker and filled the cavity. I had to use a piece of 1/4" tubing about 8 inches long to extend the nozel to feed down through the collector. I heated the tube of gasket maker so it flowed freely and filled in the cavity. No leaks for several years now. I did not want to deal with taking it to welder and risking screwing up the freshly ceramic coated pipe. Fixed for about $3.99 !!!!!

[ReMorton]

Bingo!. That's exactly where my leak is. I think I'll try the muffler pucky approach to get through the summer and then when the beast is hybernating in the garage, will pull the side pipe and do a visual.
The car is used and did a pretty thorough walk thru before purchase. This one slipped by. Now going through it doing some detailing: found the rev limiter was the wrong one, fixed that, now the engine doesnt cut out at 5000 rpm; fuel level gage not working, will pull and trouble shoot, think I know the fix; found out today that the fuses on #6 fuse box are inverted! with the 10 amp serving the flasher/heater fan instead of a 15 amp (which explains why it kep blowing fuses). So, been a challenge but a fun one to get all the pieces functioning...
Anyway, thanks again to all the folks who took the time and trouble to respond.
Bob
WDOMAKER

[ReMorton]

The muffler putty worked pretty good. Found the white stuff in a tube, loaded it into a pharaceutical syringe, filled the syringe with the goop and ran a nice skinny bead parallel to the two pipes. Cant see the repair and no paint required.So far so good...

[bobcowan]

Cool. Glad it turned out to be so simple (and cheap). there's a first.