Hey all - about a month ago I put a set of Gibson ceramic headers on my 95 w/4.0. It got another motor before I bought it, probably a 97 or 98, so the bolts all came out easily and the whole thing was pretty simple. It's gotten maybe 200 miles on it since, and I went to tighten the bolts and noticed some black stuff between the gasket and the headers, so I put the shop vac on blow into the tailpipe and hit it with soapy water - sure enough, exhaust leak. It only seemed to be leaking around the two non-factory bolts and washers - there were two bolts missing when I started the exhaust job, so I put the two bolts and random washers in to the front two holes so if I needed to replace them I could. Ordered Dorman exhaust bolts and washers and replaced the non-factory stuff - still leaking. I couldn't get a torque wrench on them, so I just tightened them pretty good, still leaked. I tightened them some more to be sure, still leaking. May have overtightened since the washer now looks like this:



It's supposedly Omix-Ada from Amazon, so it's supposed to be just like factory....so either it's a weak piece of junk or I overtightened. Just used an open-end wrench, nothing crazy - oh well.

Here's the wrinkle - the guys at Gibson said these gaskets are so tough that they shouldn't blow unless you drive on them a whole lot with a leak, so I was really hoping that factory hardware would tighten it up like it should be. My mechanic looked at it today and said if it's already leaking, probably needs a new gasket - anybody have any ideas?

Sure appreciate it!

 

Well the only thing I can tell you is to check the head and the manifold flange for flatness. Also, sometimes aftermarket headers are thinner than the intake, but looking at that picture they seem to be either the same or very similar in size. Are you torquing the bolts to spec or sending them home with an impact?

 

Yeah, I cleaned them pretty good before installation - maybe the only thing to do is replace the gasket, re-clean all the surfaces, and try again.....sigh

Edit: used a torque wrench everywhere I could fit it, otherwise just estimated by hand

 

Get a remflex gasket. They are what I use on my turbocharged 4.0s and I have yet to have a failure.

 

So are these the two bolts up in front you replaced?

 

I'll call Remflex - the way the jeep gasket section is worded, it looks like they don't have a gasket for a 95, but I bet they do...

Yes, it's only leaking where the two non-factory bolts were. Seems like even though Gibson said the gaskets are hard to tear up, using non-factory hardware may have worn the gasket enough that even factory hardware couldn't bring it back :/ Much as I hate to, looks like I'll have to replace the gasket. At least I know how to do it! Man, a few of those bolts are just STUPID hard to get to :/

 

When you replaced those two at a later stage, did you loosen all of them back up before tightening them or just the two you were replacing?

 

just those two. I did put them on the top right in the front and I seemed to recall that they were towards the end of the torque sequence - think it's worth loosening them all and re-torquing in order?

 

Yes, I'd try that before a new gasket.
Other thing would be to add a small amount of RTV or the likes to the gasket (if its like a metal gasket). But in that case you might as well look into putting a new one in anyway, since you'd have it pretty much apart again to do that.

You might get quite handy by then with this whole procedure

 

Haha you know, I was truly surprised how smoothly the header install went..... I SHOULD HAVE KNOWN. I'll try loosening and re-torquing in order - it seems to be my experience that if I RTV something that may or may not require it, it's a SURE-FIRE METHOD of GUARANTEEING I'll be scraping it off again before the job is done right.

Do you have a favorite method of cleaning off the mating surfaces? I'm gonna be DEAD sure that's not contributing to the issue if I need to take it all apart again anyway...

 

Stuff some rags in the holes to prevent gunk falling through
Gasket scraper, dont go crazy, main thing is not to cause any groove or gauches ( if that's how one spells it)

Clean up with rag soaked in degreaser or alcohol
Install the gasket of/ to your preference. With this, I'd apply thin coat suitable RTV or similar 'gasket maker' on both sides; it fills any small irregularities.


Snug the bolts according the sequence instructions and to torque spec.

Good chance it won't leak now. If it does, the surface is probably more warped than expected.


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I have NEVER used a torque wrench on the intake/exhaust bolts. The factory value was too low anyway. Use the sequence they suggest. Do it in stages, but crank em down pretty tight.

 

Yeah nor do I. I run them in with a 1/4" electric impact using the sequence. Never ever had one leak at the head.

 

In this case I would, given the OP's question whether things are too tight or not.

As one gets to get more experience with wrenching, you develop a feel for what's tight enough and what's not. Especially what turns out not tight enough over time with driving around.Torque wrench is a simple way to develop that feel a bit quicker when you start working on things. Lug nut tight after all isn't the same as fuel injector tight and nothing more dissatisfying than that last push at the end of your project and hear a crack...

Nowadays, I can't botter to go find my tw somewhere in the garage...

 

OK - loosened everything an retorqued, using the TW where I could and just going by approximate feel of medium-tight where I needed to. I will say that having to find all those bolts A THIRD TIME does make one better at it The #1 bolt in the torque order is a BEAR to get to because due to the design of the headers, it's impossible to get a socket over the bolt head, so it's got to be an open-end wrench. Seems like I finally figured out how to get to it relatively easily (after 20 minutes of deciding it was impossible).

Anyway, got it all retorqued and still leaking bad. Guess that non-factory hardware with the incorrect washers was just more than the gasket could take. Fortunately I was able to get a Remflex on Amazon Prime, so the Heep will sit in the garage until Tuesday when it arrives

Sure appreciate the help, all - as usual, actually getting in there and DOING the dreaded job was way easier than sitting here and whining about it