Timing Belt Question
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Timing Belt Question
i looked at my timing belt today by taking off the plastic cover and it looks OK, i have a 97 SC300 with 130k miles on it i just bought it and i wanted to know what are some signs of a bad timing belt and what would it look like after 130k miles if it was never replaced? nine had no crackes in it no torn pieces, nothign abnormal.
#2
It really IS kinda hard to determine the condition of the timing belt JUST by looking at it.
1. Actually, you haven't seen ALL of the belt anyway. All it needs is a bad spot that you didn't see, and the belt is subject to breakage. You would have to inspect EVERY inch of the belt, and you can't do that unless it is off the car. If you see cracks in the belt, it is PAST time to get it off regardless of miles. A bad belt can be dry rotted from years of use and still look fine. I'd rather put miles on fast than to go 9 or 10 years and feeling safe because the car has not reqched 90,000 miles.
2. Lexus recommends a 90,000 mile belt change, and there HAVE been belts that have lasted longer than 130,00 miles, but the queston is HOW much longer will it last? No one knows.
3. The water pump should be changed at 90,000 miles, although I think that with proper coolant changes, it would last hundreds of thousands of miles. The problem is that the timing belt spins the water pump, and once the seal goes bad, the hot coolant gets on the teeth of the belt, and slippage of the timing gears is possible. That will mean possible bent valves because the newer engines are zero-clearance, menaing the pistons coming up will kiss the valves coming down.
4. Normally if the belt and other parts are changed with factory parts, there is a little adhesive tag that is stuck somewhere on the engine when theparts are changed. I changed mine at 90.275 miles and my sticker is on the plastic cover for all to see. Don't forget about the stationary bearing, the tensioner bearing and the hydraulic tensioner. They all work to keep th ebelt tensioned properly, and after 130,000 miles the parts are not as strong as they were at 90, 000 miles.
5. Finally, the chance you take going over 130,000 mles on the original belt is big. Be SURE the belt has not been changed. Maybe it is not a TOYOTA belt. See if you can find a history of the car at Lexus or in a service manual in the glove box. If you know that the belt has NOT been changed, I'd make plans to get it done soon!
NUFF SAID
1. Actually, you haven't seen ALL of the belt anyway. All it needs is a bad spot that you didn't see, and the belt is subject to breakage. You would have to inspect EVERY inch of the belt, and you can't do that unless it is off the car. If you see cracks in the belt, it is PAST time to get it off regardless of miles. A bad belt can be dry rotted from years of use and still look fine. I'd rather put miles on fast than to go 9 or 10 years and feeling safe because the car has not reqched 90,000 miles.
2. Lexus recommends a 90,000 mile belt change, and there HAVE been belts that have lasted longer than 130,00 miles, but the queston is HOW much longer will it last? No one knows.
3. The water pump should be changed at 90,000 miles, although I think that with proper coolant changes, it would last hundreds of thousands of miles. The problem is that the timing belt spins the water pump, and once the seal goes bad, the hot coolant gets on the teeth of the belt, and slippage of the timing gears is possible. That will mean possible bent valves because the newer engines are zero-clearance, menaing the pistons coming up will kiss the valves coming down.
4. Normally if the belt and other parts are changed with factory parts, there is a little adhesive tag that is stuck somewhere on the engine when theparts are changed. I changed mine at 90.275 miles and my sticker is on the plastic cover for all to see. Don't forget about the stationary bearing, the tensioner bearing and the hydraulic tensioner. They all work to keep th ebelt tensioned properly, and after 130,000 miles the parts are not as strong as they were at 90, 000 miles.
5. Finally, the chance you take going over 130,000 mles on the original belt is big. Be SURE the belt has not been changed. Maybe it is not a TOYOTA belt. See if you can find a history of the car at Lexus or in a service manual in the glove box. If you know that the belt has NOT been changed, I'd make plans to get it done soon!
NUFF SAID
Last edited by gserep1; 06-14-06 at 07:42 PM.
#3
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there is no sticker anywhere, there is also nothing in the owners amnual, is there any way i can contact a dealer to see if they know if it has been done before? would there be a toyota sign on the timing belt itself?
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02-02-07 02:55 PM