My sweet sounding exhaust turned into a sour note over the past week. Last weekend I took a roundtrip in my stang of about 300 miles and since my car is an occational driver, this was the longest trip I have takeen since adding the pacemakers. I suspected an exhaust leak and just took the time to confirm it. There is a leak on top of the header at number 3&4 (soot all along the side of the carb). When I installed the header, I used Mike's gasket and ultra copper. Obviously, I screwed up somewhere since I have only about 2000 miles since installation. My two questions are 1) is this pretty common and 2) any suggestions for when I repair it.
Pacemaker exhaust leak
- Thread starter 65shad
- Start date
I'm not sure what instructions you may have followed or received, but generally -
First step is to make sure the head faces are complete and smooth. Next, ensure threads are clean and they're lubed with anti-seize.
Do a "dry fit" to pace the operation, then make sure it can be at least snugged up before the sealant starts to set firm. This is a problem in warm weather; a bead sets hard before it may flatten out.
Tightening order is to creep from the centre bolts, outwards.
Check the torque after 30 minutes' sitting. For bolts where the torque wrench won't fit, get an idea of comparative torque off one you did use it on. Re-torque when cool, after a couple hours' running and check/tighten again weekly for a month or so.
In your situation, I'd guess it's either eroded metal on the head right at the beginning, or sealant which set prematurely. BTW, the factory used locking tabs on 250-2V header bolts to ensure they didn't back out.
Regards, Adam.
First step is to make sure the head faces are complete and smooth. Next, ensure threads are clean and they're lubed with anti-seize.
Do a "dry fit" to pace the operation, then make sure it can be at least snugged up before the sealant starts to set firm. This is a problem in warm weather; a bead sets hard before it may flatten out.
Tightening order is to creep from the centre bolts, outwards.
Check the torque after 30 minutes' sitting. For bolts where the torque wrench won't fit, get an idea of comparative torque off one you did use it on. Re-torque when cool, after a couple hours' running and check/tighten again weekly for a month or so.
In your situation, I'd guess it's either eroded metal on the head right at the beginning, or sealant which set prematurely. BTW, the factory used locking tabs on 250-2V header bolts to ensure they didn't back out.
Regards, Adam.
after awhile of driving mine I had to re-torque mine as they started to leak, after that they were good.
shmoozo
Famous Member
hasa68mustang":3kbvn0fg said:
I've seen a lot of header installation instructions that indicate a need to retighten the header flange bolts a few times after initial installation.
The idea is to allow the engine to run through several heating and cooling cycles to allow thermal expansion and contraction and then retighten and retorque the bolts. Do this a few times and eventually they bolts will still be tight when you check them.
After that check them once every few months on a daily driver to make sure they are still snugged up properly, or less often on a car that is driven less frequently.
Well....looks like you guys nailed it and since I never re-tightened my header bolts, that is probably my problem. 
Rather than trying to correct the problem by tightening now, I think I will order a new gasket from Mike and start over....the right way this time. BTW, Adam, you are amazing. Half a world away and you were solving my problem in all of 8 minutes. Thanks!!
Rather than trying to correct the problem by tightening now, I think I will order a new gasket from Mike and start over....the right way this time. BTW, Adam, you are amazing. Half a world away and you were solving my problem in all of 8 minutes. Thanks!!Don't give him a swelled head 
Hmmmmmmmmmm.Could it be that he is a sleep web surfer,instead of a sleep walker?Leo
pedal2themetal45
Famous Member
Before you install the gasket check it against the head and the header.....
I don't know what Header I have but there was such a mis-match between the head and the header that with a stock looking gasket (kind of like Mikes, execpt it didn't have the extra materal over 3/4 but looked the same at the bolts) there was less than a finger nail thickness sealing the ports at 2 and 5. So I've order one from Mr. Gasket I hope its like there other gaskets and is the full rectangler gasket with the holes punched out..
Tim
I don't know what Header I have but there was such a mis-match between the head and the header that with a stock looking gasket (kind of like Mikes, execpt it didn't have the extra materal over 3/4 but looked the same at the bolts) there was less than a finger nail thickness sealing the ports at 2 and 5. So I've order one from Mr. Gasket I hope its like there other gaskets and is the full rectangler gasket with the holes punched out..
Tim
