Hey guys, newbie here. I just picked up a 95 XJ 4.0 HO , 4 spd AT, about a week ago, and i've kind of run into an issue.

Yesterday, I started noticing a knocking/rattling sound coming from the Jeep. My first thought was that it was an issue with the exhaust pipe hitting something.

The sound is more of a rattle than a knock, and it goes away at higher RPM, right around 1k RPM.

I did some digging and have seen that there is a possibility that the torque converter bolts may be loose. I haven't checked those yet, but will here in a few minutes.

In the event that the TC bolts are OK, is there anything else i can do to rule out a rod knock? I JUST bought this jeep and need it as a daily driver.

thanks guys!

 

Where is the rattle/knock coming from? That will help eliminate various things.

 

Js, I'm deaf in one ear, but from what I can hear,it sounds like the passenger side lower by the starter area.

 

does it sound something like this?


then look here:

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

 

That is right near where the exhaust pipe crosses the frame cross member. A transmission mount that is in need of replacement will cause this problem.

The vibe/thumping is typically worse at RPMs lower than 1500, and get better as the RPMs increase.

They are relatively cheap, and it is a relatively easy job to do. Most people recommend doing the motor mounts and transmission mount at the same time.

Try to get OEM mounts if possible. The cheap ones are cheap for a reason, and your exhaust will be thumping against the cross member again in no time.

 

Super, yeah it does sound like that. I was going to pull the cover but there wasn't enough time. I think that it's Def the bolts. I will also replace the mounts soon as this thing has 209k miles and I might as well get them done now.

Excellent! Now onto the driveline vibration!

 

Especially if your hearing is sub-par, one of these will be your friend. You will be amazed what this friend will whisper in your ear.

Say hi to the east bench for me! I used to live just off of Ft. Union, below the canyon.

 

One thing to note is that the noise becomes more pronounced as the engine temp increases. When it's cold, I can't really hear it, but once it's warmed up, I can hear it quite well.

 

Either way... even for the future, it's a great idea to pull the cover, threadlock the volts and reassemble. It's a good starter level project. Lots of videos around. One day/half day job. Although a helper is a good idea, for turning the engine. A head lamp is a great thing also. When working group underneath it. Even a 5$ cheapie. It'll eliminate this as an issue with noises in the future.

 

Make sure to NEVER use the red threadlock. It's permanent.

 

If it is the exhaust rattling/thumping on the cross-member, it will get a little worse as the engine warms up. Because the RPMs are higher when the engine is first started (cold), typically around 1000-1100 RPM. However, as the temperature comes up, the computer turns the idle down to about 750 RPM. These were the same symptoms I was experiencing when I realized it was time to replace the transmission mount.

This can typically be verified visually and by feeling around the exhaust pipe and cross member to see if they are touching at warm idle.