tyncobb

94 LS400 with 285,000 miles; Noticed a very small grinding noise or bearings rubbing in front of car under hood, then I drove about 10 miles back to my office and noticed the sound getting considerably louder from under the hood.

When I got to the office and while idling it was grinding and rumbling so bad that I thought something was going to come flying off under the hood. Opened the hood and noise was near front fan/water pump area but did not see any coolant or water leaking and the temp guage was normal (not overheating).

I believe it is either the Fan Bracket bearing/shaft grinding as it turns or the water pump, but am a neophyte. Can any one help me determine or tell me how to check to determine what this grinding is? I can still turn the car on, but dont want to leave it on long with the grinding so loud. THANKS FOR ANY SUGGESTIONS.

turbosix

99% of the time its that ****ing fan bracket. **** is a pain in the *** to get off, too.

change it before it locks up on you and throws a belt... it will leave you stranded eventually

trukn1

Agree with turbo. In most cases it is that fan pulley that goes bad.

turbosix

tyncobb, check my thread below

https://www.clublexus.com/forums/sho...ht=fan+bracket

jasonburt

I recommend you find and replace all the noisy bairings on the front of the motor because it costs you 10-25 horsepower. This is due to the "knock sensors" falsy picking up the noise as detonation. As such the computer will retard your timing costing you horsepower.

PureDrifter

iTrader: (10)

beyond that if he didn't the whole thing would just implode, throw the belt, stall/stop the motor, and then he'd have ZERO horsepower

jasonburt

Yes indeed, that too! Talking about noisy bearings.. I changed out my belt tensioner bearing ( 6203 RS2 is the bearing number..cost 3-5 dollars on Ebay) and injected permatex synthetic brake caliper grease in the front crevice with a hypodermic syringe..NO MORE CRICKET CHIRPING SOUNDS. Takes about 30 minutes. Maybe when I get some time I will do a DIY. Alot of people mistake this noise for the fan bracket. I did at first, until I started probing around the engine with a hose in my ear...the culprit was the belt tensioner bearing and rotation sleeve was dry.

jasonburt

I injected the grease in the crevice of the tensioner bracket, NOT THE BEARING.

jasonburt

here's a link to the bearing... http://cgi.ebay.com/6203-2RS-8-New-P...2em118Q2el1247

jasonburt

this bearing 6301 is for the idler pulley which is the small pulley towards the top of the motor
http://cgi.ebay.com/6301-2RS-New-Pre...713.m153.l1262

tyncobb

Thanks to Everyone,

Noise was the Fan Bracket Assembly and had them change the Braket, put a new Water Pump and Timing Belt with all pulleys, as well as, crankshaft seal and two camshaft seals, and then the shop called me and told me that the Drive Belt Tensioner/Pulley was going. Bought new Tensioner for $83 and had them install it too, because it would be another 5 hours probably for labor to replace any of the other items if they went bad after the fan bracket was intalled. Costs: Timing Belt Kit & Water Pump ($183.00 on Ebay), Fan Bracket Assembly ($99.00 on Ebay), Drive Belt Tensioner/Pulley ($83.00), Crankshaft and Camshaft Seals ($40.00 aftermarket); Labor from Independent Shop of 5 1/2 hours, which was 3 hours less than most shops quoted. SO, all in all, spent about $950 for everything and Lexus quoted $2000+ without the drive belt tensioner.

Thanks again to all.

Finn

Noticed while we were changing the timing belt kit that my fan braket bearings also make some noise. It calmed a bit after I injected some oil into the bearing but it's not what it's supposed to be.

For my eye the fan bracket construction seems to be such that the bearings and sealings are not supposed to be replaced or am I wrong?

Price for 16307-50011 at Sewell is $338 so it's going to take a while.

LScowboyLS

no, silly!

the Toyota fan pulley bracket is built by Toyota subsidiary Aisin, they sell the part outside the dealership, here is the information

you can find it for $95 or less at amazon