89 MJ collector/down pipe question

[coolwind57]

I've searched around the forum and other places, but can't really seem to get a definitive answer.  I have an exhaust leak at the down pipe/collector joint.  The joint is very loose.

 

Two questions:

1.  Does my 1989 4.0 have a donut gasket at the down pipe/collector?

2.  What's holding the joint together, studs or bolts?

 

I'd like the thought of tightening the two nuts to try to fix my exhaust leak there this weekend, but I need to use the truck and I'm worried I'll break those very rusty fasteners and ruin my weekend hauling plans.

 

If those are bolts holding the joint together, then I'm probably ok if I break them....easy fix--unless there is a donut gasket in there that will need replacement.  Then maybe not a quick fix.

If they're studs, then the repair is a bit more complicated.  I may wait and get it all done when I can afford to have an exhaust shop to make me a custom non-crush down pipe.

 

Truck has a cat delete by the way.  Single O2 is still there above the collector.

 

Anyone know how for sure how this area was done on 89 models?

 

  

[ComancheKid45]

OEM headers had studs into the downpipe, if it's aftermarket then it'll more than likely be bolts, won't know till ya look sadly. As for the doughnut gasket, chances are if there is a leak there it would be worth replacing.

 

I'm willing to bet you have a cracked exhaust manifold itself that's leaking, over a loose joint at the downpipe...

[coolwind57]

1 hour ago, ComancheKid45 said:

OEM headers had studs into the downpipe, if it's aftermarket then it'll more than likely be bolts, won't know till ya look sadly. As for the doughnut gasket, chances are if there is a leak there it would be worth replacing.

 

I'm willing to bet you have a cracked exhaust manifold itself that's leaking, over a loose joint at the downpipe...

 

Oh there's no doubt about the leak at the down pipe.  The down pipe practically dangles below the collector.  Could very well be a header leak too, but exhaust gushes from the collector joint.

 

Some years had no donut gasket, so that's why I was asking about whether or not 89s had them.  

[cruiser54]

It has one. Never seen a stock one that didn't. 

[sinkrun]

 I think the studs if broken can be pounded out without much effot at least on the bench i never did them in the truck,

[yxmj]

The confusion might come from the research....a YJ of that Era did not come with a doughnut (4.2)

And I have a 92 YJ 2.5 that is the same....that every year or so needs the bolts tighten to stop the slapping sound at start up.....

When my 87 MJ started slapping and popping I just automatically got under there with the socket and extention and tighten them up....never looked to see if there was a doughnut..... But she stopped making noise??

 

 

[HOrnbrod]

According to the infallible factory parts manual:

 

For MJs with stock exhaust systems; the 4.0's all had the doughnut seal at the exhaust pipe and the 2.5's did not.