Exhaust leak after shorty header install

Well the rtv between the mid pipe and header didn't help, so it must be leaking at the header gasket. while i'm waiting for the kooks gasket to get here i'm going to loosen all the bolts and try tightening them again starting in the middle. sucks that i can't use a torque wrench. trying to guess how much torque you are using with a little 10mm wrench ain't fun.

I dont know what I was expecting to find. Trail of soot maybe. The flange looks straight. Probably straighter than my straight edge. Kooks gaskets will be here tomorrow. I'll just put the kooks on the driver's side and see what happens.

Make sure you clean off the head and the header flange. I used brake cleaner and emery cloth. Make sure the threads on studs and bolts are clean too. Then spray copper seal on both sides of the Kooks gasket and you should be good to go...

JC SSP said:

Make sure you clean off the head and the header flange. I used brake cleaner and emery cloth. Make sure the threads on studs and bolts are clean too. Then spray copper seal on both sides of the Kooks gasket and you should be good to go...

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i cleaned them using a green scrub sponge and a razor blade, along with 91% rubbing alcohol. some of the new gasket material stuck to the head. it has some sort of graphite coating on it, not sure what it is. yeah, i got the copper seal spray, i assume it will stay sticky so i can stick the kooks gasket to the head. that's my hope anyway since the kooks doesn't look like it has little tabs to hold it in place like the oem gaskets. i laid that level flat against the headers and shined a flashlight on the other side and couldn't see any light, thing is straight.

These kooks gaskets supposed to be 4 layers? looks crazy, well see how they do. I'm guessing the smooth side faces the header? upon googling i get mixed results, but most seem to say smooth side towards the head. i don't think it really mattes because they gonna get crushed! These are the same as the percy gaskets. They even say seal 4 good on the package.

Flat side against the head.

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msvela448 said:

Flat side against the head.

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By flat side, i hope you mean smooth side and not the concave side, because that's what i did. putting the smooth side against the header didn't seem to line up right anyway.

You got it. The cylinder head has a nice large surface for the smooth side of the gasket, and the concave side conforms to any imperfections of the header flange.

If you are still using the stock studs and lock nuts it will be hard to torque them evenly. The stock nuts are pinched slightly so they bind naturally, so they may feel tight without actually being tight. That's why I recommend new studs with new nuts, washers and lock washers.

You DO NOT want to over tighten those stock studs / nuts... That's an easy way to get broken studs under heat cycling, and they are a pain to remove.

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msvela448 said:

You got it. The cylinder head has a nice large surface for the smooth side of the gasket, and the concave side conforms to any imperfections of the header flange.

If you are still using the stock studs and lock nuts it will be hard to torque them evenly. The stock nuts are pinched slightly so they bind naturally, so they may feel tight without actually being tight. That's why I recommend new studs with new nuts, washers and lock washers.

You DO NOT want to over tighten those stock studs / nuts... That's an easy way to get broken studs under heat cycling, and they are a pain to remove.

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I don't think i could over tighten them if i wanted too since i can only get a 13mm and 10mm wrench in there. Well i put the kooks/percy gasket in with copper seal sprayed on both sides and got the same damn ticking for the first 20 seconds after a cold start. didn't even change the tone, nothing. I put anti-sieze on the mid pipe flange this time and looking at where the mid pipe is making contact i'm not sure it's not the source of my leak so i gooped red rtv all around the flange then just snugged it a bit till rtv started to come out. i'll torque it tomorrow and start it up. i can't believe that kooks gasket is leaking just like the stocker. it's so soft and thick that even if it's not torqued evenly i'd think it would still seal. at the very least it would change amount of the leak. I'm feeling a little aggravated now. I'll be putting the stock manifolds back on next week if i can't fix this ticking. With my luck lately the ticking will still be there and it's something with the lifter. I don't believe in coincidences and i can't believe it was always there and the headers amplified it, i won't!

if anyone is interested in changing their allen head bolts that came with the prothane motor mounts, these work. i replaced mine this last time since i can't get a socket on the motor mount bolts now. you'll want a 16mm ratcheting wrench though. https://www.amazon.com/dp/B091FXYYW9?ref=ppx_yo2ov_dt_b_product_details&th=1

Same tick after sealing the mid pipe. Going back to stock. i'll try retorquing one more time. I think there's a crack in one of the pipes or a pinhole at one of the welds. hard to believe that gasket is leaking. I'll try to seal them the best i can and pressure test them before i paint them and sell them for dirt cheap on ebay.

I'd check to make sure the noise isn't coming from the phasers before tearing it apart again. I just went back and listened to the video and it sounds like the phaser tick that I had in a 2004 F150 5.4 work truck. It always went away after tunning for about that amount of time.
Grab a piece of 1x2 or some other stick of wood and put it right on top of the cam cover and put your ear to iton startup.

I think i'm going to run it for a few days to at least build up some soot so i can see where it's leaking.

RED09GT said:

I'd check to make sure the noise isn't coming from the phasers before tearing it apart again. I just went back and listened to the video and it sounds like the phaser tick that I had in a 2004 F150 5.4 work truck. It always went away after tunning for about that amount of time.
Grab a piece of 1x2 or some other stick of wood and put it right on top of the cam cover and put your ear to iton startup.

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It's not coming from the cam cover. i used a 3/4 piece of flexible conduit against my ear. it's coming from the rear of the header flange. i'm going to try and sand it flat on a flat surface of my garage floor. my belt sander is not long enough. Still can't believe this thick aluminum gasket can't seal it.

Might want to take it to a muffler shop and have an expert look at it…

JC SSP said:

Might want to take it to a muffler shop and have an expert look at it…

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What are you trying to say? Either the header is leaking at a weld or the flange is warped to the point that even the aluminum gasket can't seal it. I ordered a metal ruler from amazon, can't find my framing square anywhere. i will get to the bottom if it this week. What's one more time pulling the drivers side header. i'm getting really good at it.

I am Saying that an exhaust expert with the vehicle on a lift can possibly identify the issue… just an option.

moooosestang said:

What are you trying to say? Either the header is leaking at a weld or the flange is warped to the point that even the aluminum gasket can't seal it. I ordered a metal ruler from amazon, can't find my framing square anywhere. i will get to the bottom if it this week. What's one more time pulling the drivers side header. i'm getting really good at it.

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Like I said... My bet is a warped header flange at the cylinder head. I've never had a set (in 30 years) that didn't need sanding / machining. Does the tick go away as the engine heats up? If so it's a leak at one of the sealing surfaces which closes as the metal expands under heat.

I think it would be pretty rare to find it at the ball and socket connection at the collector unless something is pretty bent and not round, or the bolts are loose.

Good luck... Once you solve this it will be very satisfying.

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JC SSP said:

I am Saying that an exhaust expert with the vehicle on a lift can possibly identify the issue… just an option.

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I knew what you were saying. i tried putting a smilie in there, but this forum doesn't support them. I admit i am not an exhaust expert and a lift sure would be nice.

msvela448 said:

Like I said... My bet is a warped header flange at the cylinder head. I've never had a set (in 30 years) that didn't need sanding / machining. Does the tick go away as the engine heats up? If so it's a leak at one of the sealing surfaces which closes as the metal expands under heat.

I think it would be pretty rare to find it at the ball and socket connection at the collector unless something is pretty bent and not round, or the bolts are loose.

Good luck... Once you solve this it will be very satisfying.

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yes, it goes away very fast. makes it hard to pinpoint, but i'm certain it is one of the two middle ports. I will check it tomorrow with a legit straight edge or as straight as china can make them. I checked my stock manifolds today and they are perfectly flat after 17 years and almost 60k miles, 50k being supercharged. Not to shabby ford.

god this thread has spooked me so much lol

I have a set of BBK shorties about to go on, I now have three different sets of exhaust manifold gaskets and am now contemplating hitting up my local machine shop to check square on the header flanges before they get installed

Jwood562 said:

god this thread has spooked me so much lol

I have a set of BBK shorties about to go on, I now have three different sets of exhaust manifold gaskets and am now contemplating hitting up my local machine shop to check square on the header flanges before they get installed

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that's not a bad idea. if your flanges are flat then the stock gaskets will work fine, my passenger side never leaked. I think i'd use a crushable type gasket though because they may leak in the future from warpage. If you are doing this yourself i'd recommend using all the bolts bbk supplies. I only used the minimum necessary and kept as many studs and stock nuts as possible thinking they would be less likely to back out. That might be true, but like msvela448 mentioned it's hard to tighten them all evenly when some are 13mm nuts and others are 10mm bolts. I'm removing mine today and replacing all the studs if i can get them all out. cracking those studs can be nerve racking. i'd use the two nut method or use a torque wrench set to 25lb ft and just kept bouncing it back and forth. Be sure to have a 13mm flexible ratcheting wrench! it makes removing the stock nuts so much easier.

Other than my small leak on the drivers side when cold the car runs fine, hasn't thrown any codes, sounds like it has a better flowing exhaust. The sound at idle is awesome. The sound at the X pipe is intoxicating, but you have to be under the car to really hear it. i need a sound tube to my X pipe, lol! I'll make a video from underneath when i start it back up.