AndrewRM

So I have one issue with my new 1999 that I have not been able to diagnose yet. Everything on the car seems mechanically sound after checking it all over. I just got new tires, so it rolls perfectly smooth.

I have a weird vibration that is coming from an unknown location. It happens when the engine revs whether it's in park or moving. It's generally pretty low in the Rev range and it is not really consistent. It's a fast pulsating feeling that seems to increase with the revs. I can best describe the feeling like "bass". You can't hear it but you feel it in the seat.

For now I've ruled out the engine mounts because under revs the engine does not move when I feel the vibration. Haven't checked the transmission mount but I feel like it wouldn't be the case if I feel it when the car is parked.

I've heard that a pulley could be out of balance. Is this a good guess?

Thanks for the help.

valex

AndrewRM

I have 114k miles. I will take a better look at the mounts soon. I need to get someone to help me rev it while I inspect the mounts. I may also get a stethoscope to better locate the issue.

bradland

Next time you are at a stoplight put the car in neutral. If the vibration goes away it's prob the trans mount.
Pretty good chance replacing just the trans mount will fix the issue...

AndrewRM

Like I said, the vibration happens when in park and moving. That's kinda why I don't think it would be the trans mount.

bradland

Your post is only a few hours old and the only 2 ppl who responded have suggested the same thing.
I'm not trying to be mean but, there's a tremendous wealth of knowledge on this forum, if you don't want to listen don't waste our time.
We are here to help but assuming you already know the answer doesn't do anyone any good...

RA40

iTrader: (6)

Unlikely a pulley those are low mass that won't really be felt through the car. You'll hear them squealing as the races or bearings are dry worn. Top issues with vibrations are engine, tranny mounts followed by carrier bushings or the drive shaft coupling. If the vibration is present when the car is not moving, as above, tranny mount is a high possibility. Most come out in two pieces as do the engine mounts at this age. Replacing the engine mounts makes a huge difference.

https://www.clublexus.com/forums/ls-...t-coupler.html

AndrewRM

Thanks for the suggestions. Time to get to work!

Losiracer2

If your car hasnt had mounts replaced, then there is a high likelihood that yours are old and worn/tearing. After I did my front mounts and the previous owner did the trans a year prior, I felt absolutely no vibration coming into the cabin whatsoever. I couldn't even feel the car start up, it was that isolated.

Plus, we're talking about 19-20 year old rubber mounts here, you may not think they're bad, but they probably are, or are very sagged by now with the weight of the engine on them for so many years.