YJ exhaust leak drove me nuts

[JackstandJohnny]

i think its coming out of the exhaust donut on the manifold.  i don't think the manifold itself is cracked;  can't see a crack, i think the compression fitting on the exhaust is just not sealing.  
any ideas on how to get it super tight?  can i use that exhaust sealer crap from canadian tire or what?

[Pookapotamus]

get a new dounut and tighten the snot out of it!

[JackstandJohnny]

hi ho, hi ho, off to NAPA i go!

if i break a stud off pook i'm stealing your exhaust manifold

[WagoneerXJ]

Didn't think 4.0's used exhaust donuts. Just ball/socket type flanges like Fords...?

[JackstandJohnny]

don't know. the manifolds on an XJ engine and the exhaust is the YJ exhaust.  it bolts right up but its still leaking. i don't see a crack in the manifold.  will do more investigating tonight i guess.

http://www.4wd.com/productdetails.aspx?partID=5570

found this. might run to autovalue and get one and replace it.  whats the worst that can happen?

[SwampSinger]

we talked about this last night .... you know where I live

[BlackYJ]

don't know. the manifolds on an XJ engine and the exhaust is the YJ exhaust.  it bolts right up but its still leaking. i don't see a crack in the manifold.  will do more investigating tonight i guess.

http://www.4wd.com/productdetails.aspx?partID=5570

found this. might run to autovalue and get one and replace it.  whats the worst that can happen?

Johnny, why are you troubling yourself with such a minor thing.  You need to take your Jeep to a muffler shop and get a whole new exhaust built from the flange back.  Run the exhaust in front of the oil pan like the newer models, ditch the cat and run a 2.5" dynamax super turbo muffler and call it a day 

[JackstandJohnny]

scott you make a good point

put a new donut on. the old one was icky.  can still smell traces of exhaust. 

Dom. what you up to tomorrow? maybe i'll come by.... anytime

[mike s]

Ultra-copper silicone is the best for sealing exhaust surfaces, made by Permatex i think. It's just a high temp silicone that's supposed to be sensor safe. Used it on machined manifolds on V8's with no gasket at all, lasted years so far.

[JackstandJohnny]

Ultra-copper silicone is the best for sealing exhaust surfaces, made by Permatex i think. It's just a high temp silicone that's supposed to be sensor safe. Used it on machined manifolds on V8's with no gasket at all, lasted years so far.

hmmm.......



to update. manifold is not cracked. its comin out the donut still.   i still just don't know why it won't seal.  i'm debating something like the silicon or that exhaust sealer stuff.  
drivin me bonkers

and no its not comin in the back window/  theres no doors/roof on the jeep and its still bad. 

[BlackYJ]

hmmm.......



to update. manifold is not cracked. its comin out the donut still.   i still just don't know why it won't seal.  i'm debating something like the silicon or that exhaust sealer stuff.  
drivin me bonkers

and no its not comin in the back window/  theres no doors/roof on the jeep and its still bad. 

  I already told you the solution Johnny 

[JackstandJohnny]

I already told you the solution Johnny 

you might be right..........


i lathered it up with the copper silicone RTV yesterday and it didnt' do nothing. starting to think the downpipe is fubared or something.........

scott i'm already pricing ehaust from the manifold back   i'm thinkin a big stack through the back

[dac]

This picture was taken in my back yard and doctored to display what John should do for exhaust.  Needs a bigger hole in the hood or no hood at all.......

[JackstandJohnny]

so. figured i'd update this instead of make a for sale add (cause i'm almost at that point)

siliconed the donut and patched at the cat.  kinda smell exhaust still. specially with the roof on.  with roof/doors/back window all done up its not bad at all.

tonight i ran some seafoam through it again.  and presto! no leaks! at least that i could see. 

so how can i still smell exhaust?

goin into the shop tomorrow.  hopin for answers

[BlackYJ]

I had problems with mine that with the soft top on and if the back window was up or not all the way down, I would get a very bad exhaust smell coming back into the heep.  I never did figure it out but it is gone now