How to fix exhaust leak
 

What's the best way to seal the flanges? Installed ACE headers a month or two ago and they are leaking like crazy. I used the new ace gaskets included with the header, but the harbor freight torque wrench I had didn't work so I went with good'n'tight. Is Ultra copper max temp RTV gasket maker recommended? Bought a tube yesterday, any tips on how to apply it (or not) are appreciated.

Follow directions on the package. Clean everything really well too

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Are they leaking at where they bolt onto the head(s)? (as opposed to the outlet end).

If so, I suggest you take the headers off, clean up the flanges and gaskets, make sure the bolts aren't stripped and the gaskets are in good condition, fit the headers to make sure they fit flush (that they aren't warped).

Apply the gasket maker, torque down the nuts uniformly and evenly.

:thumbsup:

I'm not sure yet, I'm building a leak tester this week and will see where exactly it is. I noticed part of the front jacking point has a significant amount of soot, and the door jambs also have a bunch of it, not sure if that tells you anything?

To clarify, you suggest I re-use the gaskets, as well as the the gasket maker?

Question: How does exhaust soot get around door jambs? - :confused0068:

Well, first off, if you are under 50 years old and/or are new to wrenching, I suggest you buy a torque wrench.

I reckon it would be OK to reuse the gaskets if they were the right ones and they are in good condition.

Back in the day, in my wrenching days, when pieces were put together with gaskets in between them (and not just sealant), I would use gaskets AND gasket maker. The main job of the gasket maker was to hold the gasket in place while installing the piece - ;)

I hope you find and get your leak repaired.

For exhaust verify the flanges on the header are flat. If not you can flatten them by holding a file flat on the flanges and filling them down. If you have a belt or disk sander available that will work better and quicker. 2nd is new good gaskets, I would get the turbo gaskets. 3rd is no gasket maker/sealer/whatever. It is an exhaust and all that stuff just makes things worse. There is a flame coming out of the heads and the exhaust will glow red. This is around a 900+deg F temperature. Well above any RTV’s ability.

Curious, how do you build a leak tester?

They make smoke generators that work well. Easiest way is to use the pressure side of a shop vac and stuff it up the exhaust, then spay everything down with soapy water.

Interesting.. thanks!

I'm not sure how, I assume the gases get vacuumed when stationary and with/without AC recirculation on. Ever since I installed the headers there is a noticeable exhaust smell in the cabin and there is black nasty soot in random places but especially near the front subframe/skidplate.

I do have a 1/2 inch Precision Instruments torque wrench that is my favorite tool of all time, but for the headers the torque needed was too low and the smaller HF torque wrenches did not work. Got some Husky ones now that work alright.

and thank you :cheers:

I really hope the header to engine block flanges are sealing fine. Gaskets and header were both new on install, would suck to unbolt them and file them at this point. :(

I'm following this gentleman's video. You can do the shop vac and soapy water method but the smoke machine is substantially more reliable and easier to use. suffer once and enjoy for life. for checking the EVAP system make sure to set your compressor to < 1 psi or get a propane 1 psi regulator please! for checking the exhaust you can use a pair of silicone gloves to seal both exhausts and open a hole on a single finger to plug the tester in. don't need a lot of pressure either.

https://www.youtube.com/watch?v=tixozqgSwN0

Plumbus,

Take a look at Remflex exhaust gaskets.

Being a thick graphite-steel-woven mesh matrix gasket, it can compensate for any uneeven surfaces, T-expansion, etc. Once you torque them to spec, you don't need to re-torque them after the initial heat-cycle phase.

You can get a sheet of the remflex material and make your own gaskets.

Only disadvantage is they are a "one time use" only item and are very brittle /not ductile (you can "break" them like a cookie :) )

--> I use them on my car for the header-overpipe and overpipe-frontpipe connection (Gruppe-S exhaust manifold, AVO overpipe and custom Bastuck-HJS Euro5 CAT front-pipe).

Disclaimer: I'm not paid or sponsored by Remflex. I'm just posting my personal experience (a lot of headache due to leaking flanges and out of spec LTFT values).

To piggyback off of this thread, I too have an exhaust leak, just installed a used header so I have to figure out what's the cause still. Had a friend warn me of carbon dioxide poisoning, is that a real concern I should be worried about? I'm getting no exhaust smell in my car at all when I have the AC on/fans on and whatnot so I'm not sure if it's an actual problem or not. Would appreciate it if someone could ease my concerns on that issue.

CO and CO2 poisoning would only be a concern if you would run your car inside a sealed area/space (running the car in a garage with the windows down).

A more pressing issue are out of spec fuel trim values due to introduction of unmetered oxygen into the range of the O2 sensor due to exhaust leakage (engine - header, header - overpipe connection).

Plug one of the exhaust tips, stick the hose-end of a shop vac (blower function) into the other exhaust tip, turn on the vac and spray soapy water onto the aformentioned connections (spray it also on the overpipe - frontpipe connection or other areas you might suspect an exhaust leak is present).
Bubbles present --> leak --> fix the leak. :)

Loosen the entire exhaust and torque it back up from the front to back making sure there isn't too much pressure on the joints. Use multilayer gaskets between all surfaces, you shouldn't need anything else.