Am going during this weekend to change the timing belt in my ls400 2000

i have bought these parts so far :-
- 2 idler 13505-50030 & 13503-50011
- tensioner 13540-50030
- 4 ltr toyota coolant
- timining belt 13568-59095

do i have to replace the tensioner or no?! the mechanic told me it is not required to be changed, but i have read here in the forums that most people change this part too?!
do i have to replace the water pump?! if yes then do i have the change the water pump its self or water pump' s bracket only? there are two parts within water part!

i don't want to change un-necessary parts!

BTW my car' s engine runs great without any sounds

Please advice!

what's the mileage on the car?
When the dealer changed the belt on our 98LS, it had only 80K at the time and they said that they normally only replace the WP and tensioner on higher mileage cars. I would personally change them for peace of mind. Most TB failures that I have seen is due to the tensioner going bad. Plus the seal around the water pump can only stay good for so long.

Here's a data point to consider: The PO of my '91 always had the car serviced at the dealer and basically always did what they wanted to do. They did the T-belt at 90k with no water pump change. Then the water pump failed at 122k and he had to do another T-belt (they replaced idlers, etc. again at that point).

So I would recommend replacing the water pump. Sorry, I don't know about the 2000's water pump specifics, but anything that could wear, I would replace. More of an issue for you with the interference engine.

change the water pump itself (there's no water pump bracket, i believe you're talking about the fan bracket?) and the o-ring/gasket that goes with it, tensioner, all the idler pulleys, front main crank seal if its leaking at all, and the belt. the only thing you can skip if they arent leaking are the camshaft seals because in the 98-00 they aren't simple to replace and you have to take teh cams out to swap them.

on the 1uz, it's not usually the timing belt that breaks, it's usually (at high mileage) one of the idlers or the the water pump that locks up and then shreds the belt. in an interference 95-00 that's a BIG failure.

i have bought this engine (55239 miles) on it/dont know if timing belt has been serviced before or not, engine have been installed on my car, now this engine has 67239 miles

no service record through lexus? you can probably request for them to look at the history of your ls400! i agree with puredrifter replace both components. You don't want your water pump or tensioners to lock up

just change it all out and you will have a reference point to go on, from then on..... too much wondering and worrying for the few extra dollars it will cost.

Until you start the tear down you can't say for sure if the tensioner needs replacing. If it is still keeping the belt taut its probably good. The water pump is another story. The fact that you are doing all the labor it would be very foolish to not replace the pump. Aisin is the best brand. You can find it I think at rockauto.com or autowarehouse.com. Also, take a close look at the serpintine belt. Any doubts, replace it since you're already in there.

Until you start the tear down you can't say for sure if the tensioner needs replacing. If it is still keeping the belt taut its probably good. The water pump is another story. The fact that you are doing all the labor it would be very foolish to not replace the pump. Aisin is the best brand. You can find it I think at ******************.com. Also, take a close look at the serpintine belt. Any doubts, replace it since you're already in there. Lastly, next time you do a big job like this, buy a kit and you will save a lot of money.

I had to replace my fan bracket (bearing started making noise) after the I replaced the timing belt, idlers, tensioner and water pump. The water pump had a white crust at the weep hole indicating a small leak which didn't drip to the ground. Replacing the fan bracket involved removing everything up to the cam covers again.

Most people seem to just replace everything (and I did the same) on the grounds that it's a big job, and that you're going to be in there once in a blue moon.

The FSM does have a procedure for resetting the tensioner so that it can be reinstalled, though, so Toyota doesn't insist on replacing it. BTW doing the timing belt on cars like this with an automatic tensioner is wonderful! First tbelt I ever did was on a Maxima. Second tbelt I ever did was immediately afterward on the same car, to reset the tension. You live, you learn...

YES!!!

Changing the timing belt/water pump ($1k easy) and not replacing a $30 tensioner on an interference engine is lunacy.

End of story.

Edit: if youre going behind the crank pulley replace everything, including crank and camseals. One $20 part in that area can toast an interference engine. Are you doing this yourself? Dont even try or you will bend valves resetting the cam timing.

ERROR: not the camseals, Chilkoot, is not up on his model changes (98-2000)

Guilty. My knowledge is ucf1x based.

Thanks for pointing that out.

Mission completed. My mechanic took 5 hours to get this done. Thanks everyone.