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  #1  
Old September 16th, 2013, 20:22
SuperRA SuperRA is offline
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Does an exhaust gasket leak smell like exhaust?

I recently started up my 87 4.0L Renix after refreshing it 6 years ago. It went and passed smog like it was a piece of cake. I think I can hear a faint exhaust leak in the engine compartment, but I can't be sure. Do these motors just kind of sound like that? A slight bit clackity? I can't smell exhaust at all, but maybe it's too small of a leak? 6 Years ago I had the head off and cleaned it all up. I installed new gaskets and all and then drove it maybe 5 miles and then it sat for 6 years until today.
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  #2  
Old September 16th, 2013, 21:24
joe_peters joe_peters is offline
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Re: Does an exhaust gasket leak smell like exhaust?

Get yourself a 3'-4' piece of hose (I prefer vinyl tubing).

Stick one end of the hose/tubing into one functioning good human ear.

Move the other end of the hose/tubing around the suspect area of the engine.

TOTALLY UNNECESSARY WARING--KEEP FLESH, CLOTHING, AND HOSE/TUBING AWAY FROM MOVING ENGINE PARTS.

If there is an exhaust leak you will be able to isolate it--BE CAREFUL, WHEN YOU GET CLOSE TO THE SOURCE OF THE LEAK YOU CAN INJURE YOUR EAR FROM THE NOISE.

Good luck.
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  #3  
Old September 16th, 2013, 22:45
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8Mud 8Mud is offline
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Re: Does an exhaust gasket leak smell like exhaust?

Sometimes the small leaks can be hard to find, it is tight in there and hard to see. A mirror and a good flashlight can be helpful. Also pulling out the air filter box really opens thing up some.

I've spotted leaks on a really cold morning when I first start the motor up, the leaks blow white condensation smoke you can see.

One of the guys came up with a good idea, pour a shot glass full of oil slowly down the TB, any exhaust leaks will blow smoke (and stink of oil). That is how I spotted my last leak, the gasket was blown out in the rear of the intake exhaust manifold. I used ATF instead of motor oil, just because I had it handy. Spray oil may also work, though I haven't tried it yet.

It could be tick in the top end or even piston rod bearings. How is your oil pressure? The same plastic tubing can help you find that tick. Just don't get fixated on the noise and forget about the belts and that darned fan, I've come close more than a few times.

Last edited by 8Mud; September 16th, 2013 at 22:51.
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  #4  
Old September 23rd, 2013, 23:48
SuperRA SuperRA is offline
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Re: Does an exhaust gasket leak smell like exhaust?

So I'm about to replace all the bolts/studs with bronze and was wondering if all of the bolts studs use the conical washer? If I remember when I first replaced them all with grade 8, one was either missing because a bolt broke or it never had it in the first place. That's what I'm trying to find out. Should they all have that cone washer?

I just used a few regular washers in the center position because it wasn't a shared bolt. (only intake or only exhaust, i forget which one)
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Old September 24th, 2013, 06:41
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ParadiseXJ ParadiseXJ is offline
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Re: Does an exhaust gasket leak smell like exhaust?

Does an exhaust gasket leak smell like exhaust?

Actually, it's the exhaust that smells like exhaust. If you consistently smell it in the cab then you have a leak, however small, hard to say. You may also have an issue with the firewall grommets allowing exhaust into the cab.

The "washers" need to be there...all of them. The ones on the studs are different than the ones on the bolts. If you threw those away and are using regular washers you need to get some new ones. They need to be on each bolt to properly spread the torque and keep everything properly spaced. There is another type that I have read about, but can't recall the name or where to get them.

Regular old washers do not bite like the OEM spacer/washer and could quite possibly be the cause of your issue. Are you sure the bolt is not bottoming out in the hole? OEM spacer/washer is there to prevent that and even out the holding power. So may be the reason you're experiencing a "leak". 99.9% of the parts on the Jeep are there for a good reason.

Wanna find an exhaust leak? Seafoam it and keep an eye on the engine compartment with a flashlight (even in the daytime). Any leaks in the engine bay will show themselves right away.
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Old September 24th, 2013, 09:57
SuperRA SuperRA is offline
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Re: Does an exhaust gasket leak smell like exhaust?

Quote:
Originally Posted by ParadiseXJ View Post
[B]The "washers" need to be there...all of them. The ones on the studs are different than the ones on the bolts. If you threw those away and are using regular washers you need to get some new ones. They need to be on each bolt to properly spread the torque and keep everything properly spaced. There is another type that I have read about, but can't recall the name or where to get them.
All of them are there except one. The center position. I didn't know if all of them had a washer or not as I never saw it with all of them on. Come to think of it, I should have looked at the motors in the junkyard when I went to get a few more of the washers just in case. Well, I'll be putting one washer back on all of the bolts now.
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Old September 24th, 2013, 10:10
joe_peters joe_peters is offline
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Re: Does an exhaust gasket leak smell like exhaust?

FTW:

YOU MAY NOT ALWAYS SMELL AN EXHAUST LEAK IN THE CABIN, but people can be made nauseous/sick from the fumes.
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  #8  
Old September 24th, 2013, 11:04
SuperRA SuperRA is offline
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Re: Does an exhaust gasket leak smell like exhaust?

I will be fixing it regardless of whether or not it's an exhaust leak.

Joe, I think you meant BTW not FTW? Your statement would not be a good FTW (For the Win) LOL.
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Old September 24th, 2013, 14:53
joe_peters joe_peters is offline
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Re: Does an exhaust gasket leak smell like exhaust?

Quote:
Originally Posted by SuperRA View Post
I will be fixing it regardless of whether or not it's an exhaust leak.

Joe, I think you meant BTW not FTW? Your statement would not be a good FTW (For the Win) LOL.
For The World is another acceptable use of FTW. I may be old and smell bad, but that doesn't mean I can't be "hip"!
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  #10  
Old September 24th, 2013, 16:23
SuperRA SuperRA is offline
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Re: Does an exhaust gasket leak smell like exhaust?

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Originally Posted by joe_peters View Post
For The World is another acceptable use of FTW. I may be old and smell bad, but that doesn't mean I can't be "hip"!
Ah, I never heard of that one. Maybe I'm the old one..
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