I developed a clacking noise comming from either in the trans. or in the lower half. I could not pin point where the noise is comming from.

It only does this clacking when I'm sitting idle or rev at idle. It sounds worse when just sitting in reverse. This sound is driving me nuts.

Could I possibly have a torqe converter bolt loose.

I'm all out of ideas

 

Tap on the catalytic convertor, see if you have a loose heat shield or fragments inside rattling.

 

Got rid of the cat. I'm dog kinda guy.

It's definately comming from the motor or trans.

 

Transmission mount is probably shot. Mine was driving my wife nuts so I changed it and the noise went away. Never really bothered me. Mine was real bad after changing to poly motor mounts.

 

checked and changed the oil lately??

 

always on top of oil changes and routine maintence.

 

Check that tranny mount and tell us what you find.

 

Trans. mount was good.

I did have 1 torque converter bolt slightly finger loose.
Tightened it and still makes the same sound. Like a rapid and consistant clack.

I would guess my next bet would be to check the lower half. Not sure if the crankshaft is slightly bent and causing the piston to slap, or a rod is bent.

I don't understand what would make that noise at idle and coasting. Why would it not do it while accelerating.

Could something in the trans do that?
I've ran out of ideas at this point.

 

Next thing I would check is the flex plate for cracks. They can make a noise that sounds like a rod knocking.
You need a good pry bar and a strong flashlight or drop light. Rotate and check until you have looked all the way around it.

 

When it does it, pull up on the 4x4 lever just a little and see if it stops it. Let us know.

 

She still does it!

A mecanic said it sounded like a crankshaft bearing.

Another one said could be a bent rod or lifter.


At this point I have a few options;
Check the lifters, then the rods if they are good then check the crankshaft bearings.
"will I have to pull the motor or can I access the bearings through the oil pan?"
How difficult is this to do?

Or quit dumping money in this motor and just buying a new turn-key?
Where can I get a good deal on one that you guys stand by?

Thanks for your time and patience.

 

I priced some motors today and found that advanced auto parts can do the 4.0 for $1,500 3 year unlimited mile waranty with a $375 core.

 

Nebraska.. what year and mileage?

You can replace the crank bearings by dropping the oilpan, this is done easier if you have a lift making clearance to get the pan out of the way. Take it to a few more shops asking for a diagnosis and quote.. this should give you a better idea of the problem. Ask around for a reputable honest shop.

I went with Jasper when i bought a 4.0L for my old 88, oil pump went at 28K and i had a replacement engine in 10 days. They paid for the install as well. I highly recommend them.

 

she is a 93 with 220,000.
The guy I bought it off of said the motor only had 75,000 or so. But, he could have been blowing smoke up my tail pipe just to sell it.

I was looking at Jasper and it sounds good to me. I'm checking with a few machine shops about more prices.

What did you pay for your 4.0?

 

my 1998 cherokee makes a vibrating noise but stops when I pull back a little on the 4x4 lever. Any suggestions?