I am planning to change the timing belt on my 2000 GS4. My friend is a mechanic, he told me the water pump is located outside of engine. In order to save some money, he told me just change the timing belt first without changing the water pump. In the future, if the water pump goes bad, I can change that easily.
Is it true??

My friend has a 98 GS3 he did the same thing!!!!!!!

 

Yes it is okay but inorder to change the belt you basically have to take the front of the engine apart any how. So you are already right there. It makes sense to just do the pump while you are there becasue there isnt any additional labor. If the pump goes bad later then you have to pay for the same labor to pull it all apart again. If I remember correctly the pump was like 100.00 tthat amount on such an expensibve job is cheap insurance.

 

Yea, its the same amount of labor to do the timing belt and the water pump at the same time.... you have to take the belt off to get to the water pump anyway... and once the belt is off, its only a few bolts to get the water pump off. Do the water pump too.

 

My friend told me you just need to take the drive belt out and then can be easily to get the water pump out, it got nothing to do with the timing belt!!!

Is it true??

 

no, that is not true. the water pump is behind all of the covers, and it takes quite a bit of labor to remove it. On the GS300, it is external.. but still requires removal of alot of the covers to replace it. Trust me, replace the water pump while you do the timing belt... im a lexus certified mechanic, ive been working for lexus for 5 years... replace the pump...

 

Thanks for your opinion!!
Beside the timing belt, drive belt , water pump, Do I need to change anything else at one time?.....like timing belt tensioner, seal or pulleys????

 

I would replace the idlers as well... as they get older, they tend to start making noise.. and its cheap insurance to just replace them now, while the front of the engine is apart. As for seals.. the crank seal is very easily changed... so i would replace that while you are in there. The cam seals, however, are a whole new story... you would have to remove the VVT-i controllers to replace them, and i would not let anyone but a trained lexus technician do that... its tricky, well, so is changing the timing belt.. make sure you do it correctly, as this is an interference engine and if you dont get the cams lined up right, and the crank spins.. you will smash all of the valves and you're lookin at a lot of cash to fix it. this is why i recommend going to someone who know LEXUS's.. not just a regular mechanic... Good luck.

 

Great that we have some one who can give correct information .... so

What is the expected life time of the waterpump? Or per your reccomendation the pumps is preemptively changed and we are unable to determine the life span of the water-pump.
[Assuming we have proper tension in the belt and standard drain and refil done of the coolant].

If only the above number is published or shared by Lexus/Toyota for their vehicles...

Salim

 

It really depends... and there is no exact life expectancy. Ive seen them start leaking as soon as 30k miles and be replaced under warranty... and ive seen customers come in at 120k miles for their first t-belt change and the pump isnt leaking yet. So really.. its a choice you have to make. Toyota/Lexus recommends replacing the t-belt every 90k. People can usually go a little longer than 90k.. but i wouldnt push it with an interference engine. 90k miles.. thats usually, what, every 8 years or so? A hundred bucks or so for a water pump seems like cheap insurance to me... The majority of the t-belt jobs i have done, i have replaced the water pump, idlers, and seals as well... i have also done a few t-belt only jobs... and a couple returned back 6-12 months later for a leaking water pump... just personal experience speaking.

 

At my 90K service, all I had done was the timing belt no water pump. everything still fine.

 

I doubt it if you friend ever work on a Lexus V8 engine. I've seen many water pump leaks at 60k + miles. Why would you want to save $100 part when it just take another 30 minutes to change out that water pump? Also don't forget this is an interference motor, if your friend isn't familiar with it he can do a lot of damaged.
JPI