Hi I am jason, I have been a member on here for 3 years and I have found every answer i needed until tonight. I replaced the exhaust donut on my 250 six tonight and still had a leak (as in found another leak), i felt around while it was running and felt exhaust coming out of what felt like a small hole directly behind and slightly above where the pipe to manifold flange is.... anyone have a pic of a exhaust manifold ? i need a pic of the backside/motor side of it near the flange. OR does anyone know if there is a machined hole there?
...... sigh... the hole is above the flange. it feels like about 1/4" to 3/8" in size. If I had a mirror i could see it and be able to tell what it is or if it belongs there. I am asking a simple question. "does anyone have a pic or know of a hole that would be in this location?"
it sounds like it could the heat pipe hole for the choke. im not sure as i have never done any significant work on the small I6s. if there is a hole there and i dont need the heat pipe for the choke i would just tap the hole with a pipe thread tap and put a pipe plug in it.
There is a casting in the manifold that is drilled for the choke heater tube. It has most likely cracked internally, and the exhaust is coming out of the bottom, which normally would draw fresh air to the choke. 2 fixes, 1 is to disconnect the choke tube ( it is now letting exhaust into the choke assembly anyway ) and plug both ends of the drilled passage. 2, replace the manifold. I would just plug the 2 holes and get an electric choke! I merely just leaned out my choke setting and that's fine for here. It doesn't usually get too cold, and on the rare occasion when it does, I don't drive my car as the heater core is disconnected. Just the underhood heat will operate the choke. P.S. Don't plug the port on the carb where the choke tube was. I got a small weedeater gas filter to use as an air filter for this port. The choke uses a vacuum piston along with the thermostat coil to operate. If you plug the port this won't operate any longer. It's there to help open the choke once the engine has started.
That is exactly what happened simple_man. i didn't realize that that hole went all the way through. looks like its gonna sound crappy until i find a day to drill and re-tap bolts that are gonna break when i take the manifold off. Thank you.
Mix up a little JB Weld and stuff it in the hole. Let it setup 24 hours and see if that doesn't fix it.
There should be threaded fittings on the top and bottom holes. You should be able to reach them ( even though you'll have to become a contortionist to do it! ) Now if they break off - - - - then it's time for the JB Weld! P.S. In the event you do have to remove the manifold, be very careful with the front and rear bolt! These two are open at the ends and rust severely! If you're not careful you'll break the little " ears " on the head off! Heat, PB Blaster, tons of patience is required!
The JB Weld has crossed my mind, i stuffed some muffler putty in the bottem hole let it set then it was blowing out the top hole. neither hole is threaded. Im thinking about taping up the bottem hole then mixing up some JB in a ziplock then cutting the corner off and using it like a grout bag to fill it from the small top hole. I hate doing things this way, I already started taking out manifold bolts until one broke..... i wanted to weld both holes shut....i priced out some nice studs with brass nuts and decided the JB is more practical at the moment, got 3 kids and another on the way. I'm not a rich man yet. at least not for 19 more years............
Yeah! 10-4 on that! I originally wanted to replace my manifold with a header until I saw what they cost!!! You can still find decent manifolds in the junkyards if you look hard. Seeing your situation, I know you don't have a lot of time to do much this way. Try calling around, though, you never know what you'll find!
I have had to fill in those heat tube holes in the exhaust manifold on both my motors. If you have or can get ahold of a solder gun and some solder you can fill the hole in and any other cracks in the manifold. cheap solder gun and some solder shouldn't run more than $20. JB weld works....but never held up long for me when I tried it. My 2 cents
