Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: JackstandJohnny on May 13, 2010, 08:19:28 AM

Title: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on May 13, 2010, 08:19:28 AM
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?
Title: Re: YJ exhaust leak driving me nuts
Post by: Pookapotamus on May 13, 2010, 08:50:11 AM
get a new dounut and tighten the snot out of it!
Title: Re: YJ exhaust leak driving me nuts
Post by: JackstandJohnny on May 13, 2010, 09:02:33 AM
hi ho, hi ho, off to NAPA i go!

if i break a stud off pook i'm stealing your exhaust manifold ;)
Title: Re: YJ exhaust leak driving me nuts
Post by: WagoneerXJ on May 13, 2010, 12:03:24 PM
Didn't think 4.0's used exhaust donuts. Just ball/socket type flanges like Fords...?
Title: Re: YJ exhaust leak driving me nuts
Post by: JackstandJohnny on May 13, 2010, 12:28:36 PM
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?
Title: Re: YJ exhaust leak driving me nuts
Post by: SwampSinger on May 13, 2010, 04:54:18 PM
we talked about this last night .... you know where I live
Title: Re: YJ exhaust leak driving me nuts
Post by: BlackYJ on May 13, 2010, 05:00:08 PM
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  ;D
Title: Re: YJ exhaust leak driving me nuts
Post by: JackstandJohnny on May 13, 2010, 08:09:29 PM
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 :)
Title: Re: YJ exhaust leak driving me nuts
Post by: mike s on May 17, 2010, 07:41:45 AM
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.
Title: Re: YJ exhaust leak driving me nuts
Post by: JackstandJohnny on May 18, 2010, 09:11:44 PM
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. 
Title: Re: YJ exhaust leak driving me nuts
Post by: BlackYJ on May 19, 2010, 07:27:32 AM
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  ;D
Title: Re: YJ exhaust leak driving me nuts
Post by: JackstandJohnny on May 20, 2010, 08:28:02 AM
::) ::) I already told you the solution Johnny  ;D

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 ;)
Title: Re: YJ exhaust leak drove me nuts
Post by: dac on May 20, 2010, 09:02:47 AM
(http://i647.photobucket.com/albums/uu197/dac1979/john.jpg)

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.......
Title: Re: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on May 26, 2010, 09:13:09 PM
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 :(
Title: Re: YJ exhaust leak drove me nuts
Post by: BlackYJ on May 27, 2010, 07:31:27 AM
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
Title: Re: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on May 27, 2010, 09:00:50 AM
is this a square headlight thing then?

called my dear ole' momma last night, a TJ owner for 13 years, and she's never had an issue of exhaust comin in the lil' TJ!  it hasn't had a roof for 7 years.......

might still do the exhaust anyways. my guess is its leakin somewhere ;)
Title: Re: YJ exhaust leak drove me nuts
Post by: tubby on May 28, 2010, 02:16:58 AM
It's not just a Jeep thing John.  I had the same problem with my Ranger when I replaced my leaky internal slave cylinder. Sound familiar? You dropped the tranny, and had to remove part of your exhaust? Did you mess up the exhaust in anyway? I bolted my Y-pipe back up after I reinstalled the tranny. I didn't align the the junction where my exhaust manifold meets the Y-pipe. Everything looked good, but I had a small leak.

Get back under that YJ and try to re-align the junction. It will take a few times and you may need to use a deadblow hammer.

HTH.
Title: Re: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on May 28, 2010, 08:57:03 AM
thanks noel. the donuts not leakin anymore ;)

to update, Al at Calgary muffler took a look today and can't find a leak.  says the exhaust is'nt that bad.  maybe a better exhaust tip pointing down, but other than that its looking ok.

he did say it smelt like i was burning rich though, and thats likely what i'm smelling. he said he could smell it when i was backing out of the garage.  wondering now if i'm just running really rich;  need to solve that......... if only i had a fancy computer  to tell me why....
Title: Re: YJ exhaust leak drove me nuts
Post by: Grease Nipple on May 28, 2010, 10:01:14 AM
if only i had a fancy computer  to tell me why....

Is that a hint?
Title: Re: YJ exhaust leak drove me nuts
Post by: Gearhead on May 28, 2010, 07:24:10 PM
thanks noel. the donuts not leakin anymore ;)

to update, Al at Calgary muffler took a look today and can't find a leak.  says the exhaust is'nt that bad.  maybe a better exhaust tip pointing down, but other than that its looking ok.

he did say it smelt like i was burning rich though, and thats likely what i'm smelling. he said he could smell it when i was backing out of the garage.  wondering now if i'm just running really rich;  need to solve that......... if only i had a fancy computer  to tell me why....

Once you  find this "fancy computer"    , and are done with it ,    I'd like some magic performed on my YJ  , it runs great um   then  , once warmed up  it runs like crap  , sounding  much like a gun fight.
Title: Re: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on May 28, 2010, 11:11:46 PM
lol. fixed the map/throttle body (changed it to the old one), put a new coolant temp. sensor in and an o2 sensor.  donno if it made a difference though.  jeeps runnin better however! 
Title: Re: YJ exhaust leak drove me nuts
Post by: JackstandJohnny on June 02, 2010, 09:17:35 AM
to update

put a 'turndown' muffler tip that sits out the rear better. most of the smell went away  ::)

sometimes the easiest route is the solution.....