Timing Belt

[swabby]

I am looking for advise.

I have a 2006 SC430 with only 10,000 miles on it.

The service manual says that the time belt should be changed at 90,000 miles or 6 years.

Given the exceptionally low mileage on the car when do you think this service really needs to be done?

Thanks

[lenore]

Man that is a tough one...The Lexus belts are really well made, but the v/8 engine is a little tougher on them...dont know why. I know on the RX300 the belt looked like new at 100k miles but when I changed the one on the Sequoia (I believe same engine as yours) the belt was worn a little. Time does put changes to the rubber composites in the belt...Maybe others have some ideas.

[TA in KC]

I think it is best just to follow the factory maintenance schedule and change your timing belt when it is six years or 90,000 miles old.

I believe your SC430 has an "interference" engine like my LS400. IMO, it isn't worth taking the chance that the timing belt might break and cause major damage that would likely require your car's engine to be rebuilt. It is also a good idea to have the water pump, tensioner, pulleys, etc replaced at the same time as the timing belt since any of these components failing would also cause the belt to break.

I far exceeded the 6-year/90,000 mile interval on my previous 92 LS400 and never had any problems- but that car had a "non-interference" engine, meaning that if the belt ever broke, it would just have to be replaced and no damage to the engine components would be done. I have heard other members of this board say it is far more likely for the water pump to fail and shread the belt than it is just for the belt to break. I don't know if this is true, but I always serviced the cooling system regularly so that could be why I never had a problem.

All that said, I would never consider exceeding the replacement interval on my current 98 LS400 with an interference engine. Its timing belt is only 2 years old, but I put a lot of miles on the car and expect the belt to have about 90,000 miles on it some time next year- which is when I will have it changed.