All right heres my situation

MAC headers 94-95 style installed on my 97 Firebird
Had last bolt break off on passenger side(number 8 primary), so I had to drill a new hole in the header so I could put a bolt in the hole right next to itThe number 8 primary has two holes to the left of it and one hole to the right). The gasket got a little screwed up when I tried drilling into it, so I installed the MAC copper one(I had a set of GM gaskets). When I started the car up, the passenger side started to leak, once it was heated up. Today I took off the header and took the un-used GM gasket and had to dremel it to clean it up, and so it would line up with the new bolt hole. I coated both sides in high temp RTV and installed it. When I started it up it still leaked as soon as it heated up, so I went through and I re-tightned all the spark plugs on the passenger side. Now for whatever reason I hear no leaks at idle, but once I start to drive around, under normal and heavy acceleration I hear a defnite leak. This is really annoying becasue now I can't hear anything at idle so I can't try and pin-point the leak.

Also for whatever reason, two of the bolts on the passenger side went in crooked, so I had to put a washer on them and tightening them with a piece of pipe. No clue why this happened, it wasn't becasue the header was warped because I tried putting the bolts in with the header off and they still went in crooked. So I really don't want to have to take the header back off.

Anybody have any common places I could check? Are there any particular places on MAC's that leak? I did some research and I saw how some people's MAC's had a slight hole were the primaries meet up. How common is that? Is there any place that will leak under accelration but not leak at idle?

Also I closed off the AIR pipes with a screw, and I blocked off the EGR with a block-off plate and a lot of RTV.


I really appreciate any help, this project has been going on for over a week and a half now and I am depressed, I'm in the middle of exams and this stupid car is driving me crazy, so far nothing has gone right on this install and all I want is for it to be back together and 100%

 

I don't know if this wil help since you said that you cant hear the leak at idle, but I tracked mine down using a piece of rubber hose, using it like a stethescope (sp?) with one end to my ear moving the other around the engine bay until I was able to pinpoint the source of the sound around my #4 & #6 primaries. You will be able to hear more distinctly, so it might still work for you.

If that doesn't work, I would say look for soot streaks around all joints or other possible places. I had to retighten all of my header bolts after several heat cycles before they finally stayed tight.

I had an idea that I'm not certain would work, but you could try it if you run out of options. Seafoam engine cleaner smokes like crazy when you use it on your engine (do a seach on "Seafoam" you'll find out all about it if you don't already know) the smoke might be visible from your leak pont in the engine compartment. Again, this is just a theoretical solution, I have no idea if it would actually work.

 

That hose idea sounds good, I'll have to try that. Do you think if I just every couple days, kept tightening the bolts it "might" eventually go away? I'm pretty sure the gasket is on there good, it has a layer of RTV on both sides, maybe it will just take a few days to seal up since I had to modify it.

Thanks for the reply!

 

How long did you wait before starting your car up and putting on the RTV? It is my understanding that it needs 24 hours to fully cure and if you just put the RTV on and started the car up after getting everything togther, then it may have not had a chance to cure properly. Definitely use the hose idea and maybe even try to sniff where the leak is.

 

an idea i wanted to try on my car is seafoam. It came to me when i seafoamed my corolla and noticed smoke coming from under the manifold heat sheild, took it off, sure enough, cracked manifold.

i wanna run some seafoam in the t/a and see if any smoke seeps out of any spots to find any leaks