JNeezy

I've been looking through threads 'til my eyes bled and didn't see anything that was close to my issue so I apologize if I just didn't dig far enough.

Little bit of background - 1995 LS400, car has a crazy noise accompanied by a vibration felt throughout the whole vehicle that correlates with the noise. I have been reading about the fan clutch and the fan clutch bracket as possible culprits - I was able to stop the fan with some rolled up newspaper.

Last night I was leaving a friends house, started the car with the accompanied noise and took off. Got down the street and around the corner and there was a hard, loud thump and my engines seemed to idle smoother, the noise was gone and my battery light came on. I knew immediately that the belt had slipped off, so I drove a little ways up the street under a lamp and sure enough the belt had come off.

I put the belt back on (in the poorest of light conditions I tell you) and started the engine. FOOMP off went the belt again. I checked all the pulleys by hand - alt, ps, a/c, idler, crank (obviously unable to turn it) but am at a loss as to what the deal is.

Noise is gone, car starts and runs but the belt will not stay on. Is it the harmonic balancer just spinning inside of itself? Couldn't really tell as the light was really bad as I said before. Any suggestions/tests I can perform in better light?

Thanks.

lex2001

There has to be a tensioner in there some where. There should be a diagram of how the belt is routed on the inside of the hood, I don't know if it will tell you which part is the tensioner. Once you put the belt on by hand you have to tighten the tension on the tensioner to keep the belt from coming off and to allow the belt to have enough friction to turn all of the pulleys. Some tensioners are a part like an alternator that has a bolt coming through a slot. Others have a bolt that you tighten after you loosen the pulley nut that comes through the piece. This puts pressure on the belt, tightening it. I don't know what kind of tensioner you have maybe someone else will chime in. The other possibilty is that something broke allowing the belt to come off and the tensioner is still tight.

deanshark

The tensioner is self tensioning. (like a spring) You need to check ALL the pulleys again for any kind of wobble or looseness, especially the tensioner and idler pulleys. It sounds like the belt is off alignment and rolling itself off of whatever pulley isn't lined up correctly. The most common problem would be the bearings going bad in the tensioner and/or idler. Alot of members have changed the tensioner and some have changed just the bearings. Check out post #10-12 for bearings in this; https://www.clublexus.com/forums/ls4...-progress.html

JNeezy

Thanks guys, found out what it was, just needed better light!

Cooling fan bracket failure. COMPLETE FAILURE. Grabbed a fan blade and wiggled it and the damn thing fell apart! Ran out of light before I could take a decent picture but I will definitely post one as soon as I can.

PureDrifter

iTrader: (10)

lol, probably wasn't helped by you driving on it like that...

Cashflo

iTrader: (1)

Mine was doing the same, the can clutch bracket, the bearings go bad in them, they make some terrible noises and if they get bad can throw the belt off.

dashan

Yes, get us some pics about the fan

Rollaboy

iTrader: (1)

wow sounds nasty. Saw someone installing and electric fan instead. Maybe this should be considered? I sure is considering it for my own 91' LS.

JNeezy

Yeah, I might after this. Have to check a few prices first.