Help with strange scraping sound

Exhaust hitting something, due to bent exhaust or worn motor mounts. Please me know what it is, because I have a '95 Wrangler too. ;^)

Earle

Thanks, I'll follow up once I find the cause.

Earle Hort> Exhaust hitting something, due to bent exhaust or worn motor mounts. Please

I would be checking out the drivers side engine mount. When it breaks the exhaust can hit the front axle when decelerating.

Mike

If that is the problem consider chaining the replacement.

You all must be psychic! The driver's side mount looks bad. The rubber that goes over the top of the center bolt is mostly gone. I recently put in a torque reaction bolt in the transmission mount that had been broken before I bought the jeep. Looks like this mount had been taking on that role and wore out.

Thanks to all who replied.

L.W.(Bill) Hughes III wrote:

Replace all three mounts at the same time, motor left/right and transmission. If you don't the motor will not sit correctly and your drive angles will be off.

Some days the ol' crystal ball works eh...

Not a hard fix anyway.

Mike

Thanks again to everybody for the help.

Mike Roma> Some days the ol' crystal ball works eh...

Just an update. Replaced the driver's side motor mount last weekend and while down there noticed that a bearing cap had fallen off the front driveshaft u-joint at the transfer case so ended up replacing the joint too. I'm hoping this will take care of the noise. I'll be going off road this weekend for testing!

Thanks again.

nrs wrote:

You should replace all mounts (usually 2 on the motor and one on the transmission) because just replacing one puts the motor at an odd angle.

Missing bearing cap will most definitely make a noise. Glad you caught it before the joint grenaded.

Happy New Year to everyone!

Well, the noise still hasn=B4t gone away (seems it wasn't the engine mount nor the u-joint). It sounds like a slow metalic scraping seeming to come from around the bellhousing area. It happens only when using engine compresion to control speed when going downhill. I've hear it now in 1st, 2nd, and 3rd gears at various times and speeds. I can make the sound stop by giving is a bit of gas or by pushing in the clutch pedal. The strange thing is that it does not seem to affect anything else, Jeep shifts ok, clutch operates smoothly, etc. Any more ideas? Any tests I can do?

Thanks

Our 4.0 did something like that when the drivers side engine mount tore. It let the engine swing just enough under torque so the exhaust hits the front driveshaft pinion.

It was a really hard one to find until one day I saw shiny metal down there....

Mike

Mike,

I replaced the driver's side engine mount and have checked for signs of contact on the exhaust but can=B4t find any. It really seems to be something in the bellhousing but don't know enough about these things to visualize what could be happening.

Thanks

Mike Roma> Our 4.0 did something like that when the drivers side engine mount

Clutch release bearing?

Merrill

nrs wrote:

FWIW: All mounts should be done at the same time or the engine and transmission will not sit properly.

The only time I had a grind/scrape under load it was due to a failed rear mains bearing. You can tell if the harmonic balancer can be moved back and forward by more than 1/8" Mine moved almost 1/2"

Sorry to say, if that is the problem, the fix is a shortblock.

Sounds pretty serious. When you had that problem, did the engine work fine otherwise?

Thanks

DougW wrote:

Yep. Good acceleration, but if you put it under any load you would get a nasty grinding noise. This was under waranty and even the dealership's chief mechanic was scratching his head trying to figure out how it could happen. The only thing I could think of was oil starvation, but it could have been a defect. Never did figure out why.