txwriter

This is my first post and I'm not at all a car whiz, but have done minor things here and there. My son is driving our '98 LS400. For full disclosure, his college roommate (who works on his own truck) helped him with the first repairs listed below, saying he'd done this before:

• Serpentine belt was replaced in February. Alternator was replaced in April (it was faulty).
• The serpentine belt broke last weekend, which we replaced.
• The crankshaft pulley was out of alignment, as in "behind" the others pulling the belt towards it. The rest of the pulleys seemed to be aligned.
• We did a very quick start. The crankshaft pulley was vibrating a bit, or at least not rotating smoothly like the others. We ran the engine for less than 10 seconds.

My next door neighbor, who has rebuilt engines, and does all his own work to his 4-Runner, said it looked like it might be loose and need adjustment. I thought I'd post here for any tips anyone can offer before calling my mechanic.
Thanks!

YODAONE

Harmonic balancer and "crank pulley " are used interchangeably.. they are one and the same assembly.

The rubber dampening ring between outer half (pulley) and inner circle side ( crank mounted inner circle) may have separated.

Very unsafe and can cause a lot of damage if it comes undone.

Do not drive until you verify.

Use correct tools to extract. (If the last person removing the balancer did not use correct tools or used the starter as an impact may have created the separation).

Refer to my post.

By the way....use only OEM harmonic balancer...

txwriter

Thanks YODAONE. To my knowledged, the balancer has never been removed or repaired. We definitely decided not to even start the car until someone looks at it. I'm having that done.

timmy0tool

iTrader: (7)

i also suspect the pulley separated from the rubber damping portion. it's common enough especially at high mileage.
it will need a new pulley and you should be golden.
and yes use OEM! aftermarket brands do not perform as well.

YODAONE

If fharmonic balancer has never been removed would suggest your timing belt, water pump and associated pulleys and tensioners have never been serviced.

Odds are agains a timing belt lasting 21 years...especially one with over 90,000 miles..

Mileage on your '98?

If timing belt service was performed, then removal of the harmonic balancer...and there are extremely few mechanics, dealer or otherwise, that use proper tools to remove and, or, install harminc balancers...

(have had friendly arguments on this forum on not using the starter to loosen crank bolt)

However, most use the starter as an impact to loosen crank bolt...tightening is another matter.

A Lexus Dealer I queried said they use a chain.. (wrapped around pulley)...which tears at rubber dampening element)

Very few technicians I trust to touch my car...even then I have to verify upfront whether they possess correct special service tools...amd the service managers all take offense.

txwriter

Thank you!

txwriter

Mileage is 199K, so I know we're due for timing belt too. That was changed at the 90K service at the dealer, so I guess (hope) the harmonic balancer was changed. I was told we'd be good until 200K so I hope that was accurate.

YODAONE

Harmonic balancers rarely are changed at 90k miles during timing belt replacement.

However, the harmonic balancer must be removed when replacing timing belt...

Whether it was removed properly or not, it seems you have identified the problem.

Just be sure the mechanic does not use starter as impact wrench to loosen crank bolt and verify correct tools are used (ask to see the tools) to install new harm onic balancer;

See:

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/863812-stop-using-your-starter-as-an-impact-wrench.html

sha4000

iTrader: (1)

I've done 2 timing belts and used the starter bump method with no dire consequences. You have to do what you have to do sometimes.