• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Engine Vibration

Sparky

NAXJA Forum User
Location
Illinois
Been doing a lot of reading here trying to find out what's causing the vibes.

I have a 95 4WD XJ 5speed with about 96K miles

I had to change my engine and trans mounts and went with Rusty's bombproof for both. You got it....vibes like crazy. I am not blaming the mounts, they are just letting me know I have other problems.

Since getting them replaced I have searched the forum till my head hurt. I ended up, so far, replacing the harmonic balancer, plugs, cap, rotor and wires. Last year my fuel regulator diaphragm had a hole and flooded the engine so I finally replaced the O2 sensor on the manifold. I also had the front u-joints in the hubs replaced and new tires put on. These just needed to be done but took away funds to replace the leaky exhaust manifold.

Without moving and revving up the engine I get a rumbling vibration that reminds me of something being out of balance. It is isolated to 1100, 2000-2300 and 3200-4000rpm. I almost replace the original CPS but am understanding it either works or it doesn't. The manifold leaks at the head, but other than a leak I am not sure if it would be a serious issue with vibes. All the plugs looked good so it doesn't look the an injector is stuck or not working, but thats just my opinion.

I'm just stumped
 
Are those his rubber or poly mounts? Poly is well-known to transmit the existing harmonicsand vibes from the engine.
 
Rubber on the engine and Poly on the trans. My mechanic put the used collapsed trans mount back in because of the vibes. Not too happy about it but I do appreciate not having my teeth chattered. Still need to get it replaced with an OEM type mount.

I just took a long drive and need to explain a little better, having the memory of a gnat.

It idles a little rough when warm after the piston slap stops. It seems to miss every once in a while, kind of like a Harley. The vibe is predominant at 2400rpm but the intensity tapers down on each side of it from about 1500 to +4000rpm. I have experienced a slight drop in performance as well which has really got me bothered.

If I had a flexplate my butt would be under there checking bolts, seems like a common issue. Not sure if the flywheels have the same problems.
 
Ok some more info for those waiting to help out.

I pulled off the injector connectors one by one and the engine stumbled with each one so thats not it.
 
Back
Top