UpInTheLex

iTrader: (5)

At an Autocross event last weekend I spun,basically 180'd and all of the weight of the car transfered rearward. I was trying to drive forwards as the car was sliding backwards. pretty much WOT. My tires didn't give (275's), the engine bogged and my timing belt skipped teeth and shredded in half along the length of it. It's half the width it's supposed to be and many teeth are sheared.

These engines are Interference Engines ? I understand that they are... Please correct me if i'm wrong.

O. L. T.

iTrader: (17)

Non interference engines. put a new belt on it and drive it.

I've removed the part of your post that violates the rules.

UpInTheLex

iTrader: (5)

I am sorry about that part, I didn't think first... Where are the classifieds now?

I feel like the luckiest guy on the planet right now, you're serious? I have a new belt sitting in my trunk. I most likely did not bend valves?

O. L. T.

iTrader: (17)

I'm not sure if you can bend the valves on a non interference engine, but.... no?

O. L. T.

iTrader: (17)

Oh, one thing though...... since your car is a 95 - call and be sure if your engine is non interference because in 95 or 98 they may have become an interference engine, looks like a lot of rumor.

It's a crossover year I believe so hold your breath and pray.

Here's a reference: https://www.clublexus.com/forums/sho...6&postcount=18

O. L. T.

iTrader: (17)

Here's one more confusing thread: https://www.clublexus.com/forums/performance-and-maintenance/46362-interference.html

UpInTheLex

iTrader: (5)

I heard the change happened in 95. thats why I say I was under the impression that it's an interference engine. I'll call the dealer tomorrow and find out for sure.

Looking through the thread you sent me, Bean strongly suggests that all Iuz's are non-interference. This would make sense to me. A VVTi engine could certainly be different but the SC400 was basically the same in 94 as it was in 95, and 96 with the exception of OBD2.

Oh yeah I forgot...
The timing belt was less than a year old!

O. L. T.

iTrader: (17)

I don't see why they'd do it in 95. I would understand '98 vvti engines.

As you can see from that thread lot's of confusing info.

jibbby

I've never heard of this happening...WOW. That sucks....I've done what you have done once or twice but never experienced timing belt damage on my 92 SC4....Strange...

CleanCL

you should replace your tensioners, sounds like they arent doing their job.

UpInTheLex

iTrader: (5)

All that stuff is new.
With these cars you do maintenence all the way or not at all.

All of the tensioners, I believe 3 of them were replaced, along with the belt, and waterpump.

I did all the preventative maintenece last August. Bottom line is it still broke.

Good news is Lexus of Serramonte says that 98 is the first year for interference engines. Putting in the new timing belt next week. We'll see...
Just crossing my fingers at this point. Hopefully the valves are ok...

UpInTheLex

iTrader: (5)

So both idlers were new. The tensioner was new. The belt was new.

The mechanic described what happened as the LSD diff locked both wheels, which are connected to the tranny.
The car was pushing the transmission to spin the engine the opposite way.
The engine was attempting to spin normally but the and my timing belt skipped off the teeth.

The car is torn down and a new tensioner and belt are currently being installed.

I'm getting rid of the 275 on the back. It's way too much tire necessary for the stock motor. I want a tire that is going to spin, not hook so well. The engine just couldn't bust the tires loose and all the weight of the car was too much for the belt to handle.

jibbby

Tires busting loose, torque, etc...should not cause a timing belt problem.. These cars handle as much as 400whp and don't have issues with the timing belts or anything...Stock engine internals, serp belt system, and timing belts should not be giving you trouble.....You may have a defect problem with the motor...

UpInTheLex

iTrader: (5)

problem was the tires didn't bust loose.

It took my rpm from 4500 to about 500 when i started sliding backwards.

You're talking over 100% load in than instance.

It's something to watch out for, If my tire would have spun, the engine wouldn't have bogged so badly. So in this case, if I'd have had more power, it probably wouldn't have happened. Case of not enough power.

jibbby

I run nos and a torque converter..... For kicks years back, I once purchased 500 pounds of sandbags and set them all in the trunk to gain rear traction...I Hammered the throttle 100% with the nos engaged and the car gripped.. The front end rised, my neck and body jerked back, then I heard a pop, pop, pop pop, pop, boom, screeetchhh....What happen with the torque being at around 400 Ft. pounds and massive traction the stock lug nuts on the driver side rear wheel snapped off instantly and the tire and rim went flying into someones front yard..The back end of the car dropped one the one side going 30mph or so and I ran on the brake rotor and elbow spindle arm to a stop...(this made a massive spark show, for on lookers)..."True story"..Had to replace the spindle and all lug nuts...Engine had no problems what so ever...Maybe some SC's have different breaking points then others under torque traction, who knows?

Are you running sticky fat slicks, Coilovers, etc?...How did obtain that much traction? I would think you would have problems with the drivetrain such as a snapping or twisted driveshaft, lug nuts snapping, 1st gear blowing out, torque converter lock up or something else before an engine issue such as your timing belt slippage..

Anyway, congrats on your traction problems, some SC owners would kill to obtain that kind of traction...I would still second guess that diagnosed problem just to make sure...