Exhaust Manifold sitting crooked on downpipe

Ok.

So basically my 90 4WD Jeep Cherokee Sport Inline 6 Manual, starts making a ticking under LOAD from behind the firewall. It was fine one day, noisy the next.

A friend thought it was where the Exhaust Manifold meets the down-pipe, mentioned a gasket might have been bad.

He tightened it up a little bit, made it worse(louder), I changed the old gasket, but for the life of me cannot get the connection between the bottom of the manifold and the down-pipe to the cat flush. It's like 5 degrees off kilter, have tried to wedge it over, it maybe budged 2mm.

So basically it sounds the exact same as before. Could my Motor Mounts be bad? Because the manifold doesn't move and neither does the down-pipe. I'm thinking if the mounts were replaced it might sit right. My tranny mount was really bad, about a year ago I replaced it and it raised my transmission a good 4-5 inches.

Any thoughts?

The engine/trans mounts, unibody flex, and rigidity of the exhaust mounting all contribute to cracking manifolds.

Check the bolts that hold the brackets to the block, they fall out or break. Put a block of wood under the oil pan and use a floor jack to lift the engine a little.

Best answer is to cut a short section out of the downpipe where it runs left to right across the vehicle, just before the CAT. Then install a stainless steel flex tube in there: http://www.cxracing.com/mm5/merchant.mvc?Screen=PROD&Store_Code=CXR&Product_Code=FLEXPIPE-250x8

That is a sample, you can shop around for and likely find a better price.

I should mention that it was crooked before I changed the gasket. Not sitting flush.

The manifold was replaced over a year ago due to the 19 year old one being cracked. It's a perfect OEM Exhaust Manifold, never made this noise before, and now the connection isnt square. I'm not trying to make more work, i.e. cutting a pipe and clamping on some extension when it was perfectly fine before.

What could cause a 5 degree tilt either on the bottom of the manifold or the upper end of the down-pipe.?

That joint seem to have some adjustability in it. When I was putting my exhaust back together, I left those 2 bolts and wiggled the downpipe around until I had it where I wanted it. Then I clamped the crap out of the bolts to seal it up. I'm pretty sure that half-donut-shaped washer is made of graphite or something that'll deform a little to seal up.

The cause may be motor/trans mounts, but to fix this I'd say:

Cut the chunk out of downpipe before the cat for a flexible section to fit.

Get a new washer from Autozone for under 15.

Line up the downpipe and crank down on those 2 bolts.

Use clamps or weld in that flexy pipe.

Ok, well then it sounds like you might need motor mounts and maybe also trans mounts...

Also, how is the rest of your exhaust? Maybe something after the downpipe rusted through/broke and shifted a bit.

HenryKrinkle said:

Ok, well then it sounds like you might need motor mounts and maybe also trans mounts...

Also, how is the rest of your exhaust? Maybe something after the downpipe rusted through/broke and shifted a bit.

Click to expand...

As I wrote in my first post, replacing my trans mount last year raised my tranny a good 4 inches.

The motor mounts are original, which led to believe need replacing.

That was my original question, if the motor mounts could be causing this. Everything exhaust wise is in great condition, even the doughnut I replaced where the exhaust manifold meets the down pipe looked like the brand new replacement

scariola said:

That was my original question, if the motor mounts could be causing this.

Click to expand...

yes

I agree with Shorty. Have you tried jacking up the engine, as I suggested above, to compensate for possible engine mount sagging?