Problems getting passanger side of midpipe to seal with stock manifolds

DVJ38

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I had taken off my old X-pipe and reinstalled many times without any issues as long as I changed that gasket. I switched from my old X pipe to a UPR X pipe and now I can't get the damn thing to seal up. I used a new gasket, and it leaked. I took the gasket out and flipped it around so that the part that sticks out a little more was facing down, and it sealed better. I figured it would seal if I just got a new uncrushed gasket in there and place it with the part that sticks out further against the midpipe the first time. Nope. I can still feel air coming out from the junction if I stick my hand up there. I measured the crushed gasket that didn't seal the first time and it was barely different from the brand new gasket (I'm talking .160" to .174"). Could I try smearing some copper RTV on both sides of the gasket and reinstalling?

I should also note that I have an ongoing misfire problem due to my cop swap going down the wrong road. First I had a misfire and noticed that the two connectors that plug into the factory harness had broken plastic tabs holding the spades in, and when I pushed the two connectors together the wires would just stick out. So I got new connectors and swapped the wires in and clicked it all together no problem. I started it up and it was great. 26 miles later it was misfiring so bad I had to tow it. So I ohmed all the coils out and found one coil to read OFL on the secondary circuit, so I threw a coil in from Advanced Auto. It ran way better but still had a miss. The car popped a code on the second start up (not sure what it was for though to be honest). I returned that coil and just ordered all new FRPP coils. Hopefully that fixes it. However, the exhaust gasket should still be sealing fine with a misfire you'd think, right?

Any experiences or tips with getting that midpipe to seal would be appreciated.


Edit: I should also note that I took a scotch brite pad to both the exhaust manifold flange and the midpipe flange to make sure there was not debris getting in the way.
 
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DVJ38

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So I mentioned how I put the gasket in the first time and it leaked, so I flipped it around so the fat part was pointed towards the midpipe and it sealed better. Well that seems backwards to me since the manifold has a ridge cut out inside of there. This website agrees with what I thought to be correct (fat part towards manifold).
http://www.terminator-cobra.com/exhaust.htm#Jet-Hot_coated_manifolds

Guess I'm taking the thing off again tonight and flipping the gasket and coating both sides in copper RTV and letting it dry. Really not sure this is going to work, but I guess it's my only option right now.





This forum is dead lately...
 

IronSnake

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Copper RTV will fix it. Installed a stop midpipe with a single eh not so tight nut and then one broken off studd. Lasted for a month that way till it leaked, and it had no metal gasket. I figure it'll fix your problem for sure.
 

MichyMuck

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You might get lucky with the Copper RTV.

I would bet that the oval part of the pipe that protrudes above the flange on the X Pipe is too long. Its bottoming out on the manifold so it wont allow you to pull it tight not matter how much you tighten the nuts. Had this same issue with my Magnaflow X Pipe and grinding an 1/8" off that allowed it to seal.

If you have your stock mid pipe around to compare you should just match the length of the protruding pipe.
 

cbrown9064

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Here is a dumb thought...are you sure the hole spacing for the studs is right? On my Bassani O/R x, the holes in the sliding flange on the drivers side were the wrong spacing. Perhaps the fixed flange on the passenger side has a spacing width that is off a bit, binding up and not allowing you to draw the flange all the way up?

Is this X one piece or is does it have some slip joints? If slip joints like the Bassani, try fiddling with just the piece off the manifold. Don't know if that is possible on yours...
 

DVJ38

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Copper RTV will fix it. Installed a stop midpipe with a single eh not so tight nut and then one broken off studd. Lasted for a month that way till it leaked, and it had no metal gasket. I figure it'll fix your problem for sure.

No gasket and only one nut holding it on with no leaks? That has to be a record lol. I'm feeling confident about this idea now!

You might get lucky with the Copper RTV.

I would bet that the oval part of the pipe that protrudes above the flange on the X Pipe is too long. Its bottoming out on the manifold so it wont allow you to pull it tight not matter how much you tighten the nuts. Had this same issue with my Magnaflow X Pipe and grinding an 1/8" off that allowed it to seal.

If you have your stock mid pipe around to compare you should just match the length of the protruding pipe.

That may be a good bet. I looked at that and I think it was pretty much even. It might be just off enough where I should consider grinding the inner pipe down a bit. I'll have to take a closer look. Thanks for the idea.

+1 Copper Seal RTV FTW. I have had to use it more than a few times to seal exhaust leaks, works like a charm!

Glad to hear another positive experience with it!

Here is a dumb thought...are you sure the hole spacing for the studs is right? On my Bassani O/R x, the holes in the sliding flange on the drivers side were the wrong spacing. Perhaps the fixed flange on the passenger side has a spacing width that is off a bit, binding up and not allowing you to draw the flange all the way up?

Is this X one piece or is does it have some slip joints? If slip joints like the Bassani, try fiddling with just the piece off the manifold. Don't know if that is possible on yours...

That's not a dumb thought at all. I know the spacing is correct because I can push the flange all the way up by hand until it meets the manifold, so that isn't the problem. Great idea though.

It's a 2 piece. There is a ball-socket flange on the drivers side of the x pipe, on the side that goes up to the manifold. That's usually the last one I tighten, just to make sure everything else lines up correctly first.



I just got the new FRPP ignition coils in the mail, so after this rain finishes up I'll be going down to hopefully figure this out.
 

clbailey

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Had a drivers side mid pipe leak with a Slp catted x with gutted cats for visual insp. Had to remove xpipe from exhaust and fully install the mid pipe first then adjust the catback to fit it.
 

DVJ38

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Well, turns out the studs have twisted out a bit. Can't believe I didn't realize that before. I tried to bottom out the nut on the end of the threads and twist the stud in but it wouldn't budge. Today I'm going to try to use a torch to get the manifold glowing read then try to twist them back in with the nuts. I guess. lol

Oh, and the pipe was barely sticking past the flange on one side so I ground that down real quick. Probably wasn't the problem, but didn't hurt to grind it flush.
 

DVJ38

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Well I ended up just getting new nuts and using a washer and lock washer. Coated both sides in copper rtv and got it sealed! Still running like crap though and throwing codes. It's July and I don't have it running yet el oh el...
 

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