mike5368

I have a 98 xj with 130,000 on it and the engine threw a rod through the block. So I had a new engine installed. Here's the problem. I have a lot of vibration while idleing and it gets worse when in gear. This was not there before the engine was replaced. I took it back to the shop and they say they can't find the issue though they do feel what I'm talking about. I have no idea what to look for at this point. Motor mounts are new and so is the transmission mount. Any idea's on what to look for?

freegdr

Is engine missing or running smooth....

ZINGGG

Did you use rubber mounts?

highmileage

timing, plug wires?

mike5368

Engine runs real smooth. No musfires ticks or anything obvious. Motor mounts are Napa replacements. Replaced wires plugs rotor cap and put a exhaust header on when the engine was replaced

The Rooster

Are the motor mounts tight? They may have loosened up... Also you said you had a header installed is the exhaust pipe on the body at all?

mike5368

All seems nice and tight. I thought the exhaust pipe right away as well but there is plenty of clearance. I had my old lady put it in gear while I searched around and it defiantly isn't hitting and the engine doesn't move when under load. But the vibration is still there

The Rooster

So the vibration is while in park and moving or just when your standing still?

mike5368

It is while in park but much worse in drive as well as reverse standing still. While moving its not so noticeable but I have always had some driveline vibes due to my transfer case drop until I get my sye.

The Rooster

Do you hear any sounds at all by the Trans area..? I'm thinking maybe your flex plate bolts are loose but it's hard to tell without hearing it for myself... Can you take a video and post it maybe... Sound is a hard thing to tell over the computer..

mike5368

I haven't heard anything around the trans but I will crawl under tomorrow and see if I can hear anything. I will see if I can get a video as well

belvedere

This, or possibly an issue with the torque converter.

mike5368

Correct me if I'm wrong but the flex plate if it were loose would make a lot of noise?

The Rooster

How loud it is depends on how loose it is ... From what I remember.... You just had a motor swap to which leads me to this direction also. It might have just started to be loosen up... It's really hard to do this over the computer sadly...

mike5368

I do appreciate the help. I will look into the flexplate and the converter. Thanks again for the help