I'm really confused on this... I've finally fixed my oil leak problem(DIY will be up when I find time), and in the process I had to loosen these 2 bolts that hold the right(passenger side) timing cam cover, and the 2 long bolts go through and though the water pump, which might have been the only thing holding the water pump's seal tight because now coolant is leaking in both spots where the bolts are even with the bolts tight and in place back.

The water pump seems to be fine it's just the seal that's causing coolant to leak. I know I need to fix the leak soon, even though I can just keep on topping it off, because one of the timing belt pulley's is now squeaking probably because it keeps on getting wet of coolant. Anyways, I have some grown folks telling me that I don't necessarily need to change the water pump, I can just clean it if ever it's just dirty, but I'm afraid of dealing with this again, if for some reason it finally breaks down after a few months.

Is it really recommended to change the water pump? My SC400 is at 185xxx miles right now, and I have also confirmed that the water pump in it is still the original one from factory, judging by the brand(Denso) and also the sealant used. (Previous owner didn't really stick with OEM stuff based on some other stuff replaced) Any help would be appreciated. Thanks CL!

 

do you know if the prev owner changed the timing belt? because normally the water pump is done at the same time. So, 185K miles, I would change the timing belt and the pump so you have many more years of trouble free driving since you took the time to fix the oil leakes. I have a 1992 SC400 with 270K miles, every 100K I do the maintenance, change water pump, timing belt, drain(not flush) trans oil, anti freeze, brake fluid, diff oil, and to this day (knock on wood) the car has never left me stranded on the road. good luck

 

See that's exactly my concern. My SC was dealership maintained until 120k, I got it at 163k. The owner in between was the most irresponsible one. There's a sticker on my SC that's says timing belt was done at 152k, BUT judging by the other parts the owner before me replaced(like coolant and oil filter) he didn't exactly go with either OEM nor good brand stuff... And since the water pump says Denso and the sealant is the black stuff from Toyota/Lexus(not the orange off the shelf one) this leads me to thinking that he didn't replace the water pump yet.

 

if I was in your shoes, I would do the water pump. I have used after market parts on my car and I have had good luck with them, for example the water pump I use is Beck/Arnley found at most neighborhood auto parts stores. I have found the pump with all gaskets for under $100, that is a great deal peace of mind.

 

Waterpump is meant to be done at 60,000 miles or 100,000 kms

 

It should be changed every 60-80k miles along with the timing belt.

 

if ya gotta pull it off to reseal it and you dont know how old it really is prolly would be a good idea to throw a new one on it would suck to get it resealed then fail a thousand miles later

 

I'll prolly change it, just waiting on funds to come by, plus my daughter is turning 7 this month and she's asking for a birthday party. Cause I really doubt the owner before my have changed it simply because he cheaped out on everything, and if it was done before him, which would be before 120k miles my SC is at 185k miles now, so it's prolly time already. I don't think it's supposed to leak anyways if it's not that old. Right now it's still leaking, but only when I drive freeway speed, probably because of pressure, but when it's plain city driving it doesn't leak. The coolant that leaked and dried up kinda formed a crust which temporarily stops leakage. Lol

I apologize if my question seems to be a stupid question, it's just that I hang around old school mechanics that always start their sentences with "back in my day"... Lol!

What's funny is, the first year of having my SC, I fixed all suspension problems, now it's all tight and stable, this year it's asking for some engine loving... Next year in guessing it'll be paint and body. The top coat feels all rough and losing its shine. I hope everything will be worth it, with all the money I'm spending on it...

 

The 1UZ is a "if it isn't broke don't fix it" engine (non-interference). The only time you cahnge the water pump is when you notice

~ Coolant loss over a period of time
~ Marbles in a can sound from front of engine
~ Obvious heat issues which will usually have the other two symptoms

The pump keeps from leaking by the tension from the timing belt. The timing belt pulls the water pump upwards and keeps tension on the shaft so it won't leak. If you remove the tension such as pulling the timing belt tensioner down and taking pressure off the belt, the pump will leak at high miles and you'll notice it leaking at that point once you are in there whereas it perviously "had no issues". That's why it always seems to go bad on people when they are in there doing the timing belt and pulleys. Once the tension is off the shaft the play allows seepage and the pump reveals it was bad the whole time. At your mileage, it's bad. If you pulled the tensioner, it would leak. It's simple wear and tear on a shaft that is spinning and being pulled in one direction. It offsets the shaft and wears it at an angle so when you hit a certain mileage, you already know the state of the seal and shaft. You just don't figure it out until you are in there and lift the tensioner if you don't know what is about to happen. Not such a surprise if you knew before you went in.

Timing belt, tensioner, and water pump is $175 shipped on ebay from a seller that does it as a package deal. Takes roughly 4 hours to do the job for most people, non mechanical persons maybe 6. I can do it with copy of Pantera Cowboys from Hell and a hand full of Hydrocodone in 2.5 hours flat.

It doesn't matter if the belt breaks or the pump fails, long as you have the parts on hand. I'd order them and keep them on the shelf until you get a chance to do the job. It's a one day thing, easy as pie.

 

Thank you for that mighty great info OLT. I actually wanted to pm you directly as I remember you going trough this with one of your SC's not too long ago, (but I can already imagine how your inbox looks and chances are you won't get to reply to me). Anyways, that's exactly what I figured out, and exactly what the old folks told me, where it's getting me is if I should just clean up the old water pump or should I change it entirely. But I guess at this mileage wether it has been change or not in the past it's is now a must change. But yeah, that is my plan, just have the parts on hand soon as funds permit, and basically wait for it to break down so I can maximize the life out of it. I do hear, a squeaking sound but like I said its coming from one the timing belt pulleys, which disappears once the engine is warmed up.

 

This is a bad water pump

 

I didnt realize the belt kept tension on the water pump in that kind of perspective. I learned something new about the old V8, I used to have. I did do the timing belt on it when I had and followed this link: http://www.lexls.com/tutorials/engine/timingbelt.html