nicksan

New to me, 1995 XJ, RWD. 220,000 miles
When I accelerate I get a loud, what sound like someone tapping their fingers on a table really fast and it increases as the rpms do, but it doesnt do it all the time, If I am just driving 15 or 20 it doesnt make a sound and it shifts ok, but when I give it gas and accellerate quickly it does it.

The Previous Owner did say that the tranny was rebuilt about 2 years ago but started making noise so they took it back and had a line replaced. When I got it, I fixed several different transmission cooler line leaks and one of the cooler lines was crushed, and the trans seal at the driveshaft had blown fluid all over the underside of the car. The fluid is full and clean.
Is there some driving technique or something I can do to verify it is the trans?

Thanks.

nicksan

I was just outside and I was hitting the gas pretty good while idleing and the same noise appeared, at least it sounded the same.

Could it be worn rings?


Thanks.

nicksan

Well...., after driving around for two days I think the tranny is fine, I think its the engine that is sounding off for a rebuild....

Right at startup theres a loud knocking sound but goes away quickly and as I accelerate the sound gets louder and louder, then as I brake the sound disappears.

The fluids are up to level. I can see that the valve cover has had the gasket replaced recently.

Does the flexplate to torque converter sound (loose bolts) go away or is it always there?, does it increase with rpms?

Same question about haveing too much side to side play in the distributor? Does that knocking increase with rpms?

Thanks.

Roler

It would be helpful if you'd be able to narrow down the location from where the knocking comes from. It does it while idling as well you said, so put in Park, handbrake on, chok wheels and crawl under your Jeep. See if the knocking is more around flex plate, more bottom end engine etc.

Knocking can always have several causes, location will help in getting some sensible advice (before already thinking engine rebuild)

nicksan

It does at idle, right as I start the car, but it quickly goes away.
I was jumping out to try to hear it, LOL but by the time I try to pinpoint it, it is gone.

But, as I posted before, while driving it becomes very loud as rpms increase and then disappears alltogether when rpms decrease and I come to a stop.

Thanks.

Roler

jack the rear up and support it on jack stands. Make sure its resting solid, you dont want it to come down during thefollowing procedure. Chok front wheels securely
shift into drive and have a listen.... have helper slowly increase the rpms while you listen...

cruiser54

Could be something as simple as bad engine and trans mounts.

Time for some noggin pokin.

nicksan

I have already replaced the Tranny mount and the drivers side motor mount.
Looks like the PO already did the passenger side.
I am going to check them out next chance I get.
I am hoping the motor mount is just loose.

Thanks guys.

nicksan

When I remove the flywheel inspection cover, What am I looking for.......... as far as whatever could be making noise?

Loose flywheel bolts?

cruiser54

If it's an auto trans, here ya go!!

https://www.cherokeeforum.com/f51/ho...ocking-125547/

If they aren't loose, click on this link before putting the inspection cover back on.

https://www.cherokeeforum.com/f51/ch...xplate-172081/

nicksan

Thanks for the links Cruiser....

nicksan

Ok, So I checked the bolts on the flywheel and one of them was not tight, but it was snug so I dont think that would cause the knocking I was hearing.

I also tighted up the drivers side mount and again they did tighten down but they were not very loose, It could be that as the car sits they are under stress and when it is moving they are relaxed and the mount moves around, just a theory so far, I had to stop for the night, I will investigate more this weekend.
Trans mount is solid.

Thanks.

4.slow95

It sounds like a bad rod bearing. It may be time for a rebuild.. Drop the oil pan and plastigauge the rod bearings. They should be between 1 and 3 thousandths. If any are past that... Time for a rebuild.

cruiser54

Don't forget to check for cracks.....

cruiser54

Not something to jump into just yet.