jjbenzo

Wow, this would be an awful situation to be in. I can see the used motor with 40k on it being a great replacement for you.

I replaced the timing belt on our 02 GS430 last fall with about 98k on it at our Lexus dealer. I did not replace the water pump as I was told it was still fine.

Ned Vo

"I have 40K miles on my one-owner, well cared for 2002 sc430. The timing belt just snapped the other day and the engine subsequently seized."

Your new "used" motor has almost the same milage as the ones above. I suggest that you should change/replace the timing belt on the ones you just purchase before installing. My car first timing belt was done in Nov 2006 at 92K. I just replaced mine with the fully built ones that I purchased through here ffrom Quicksilver RacEngine in MD. Since my old engine had 183K (yes 183K), I parted it out to look for wear and tear etc...Everything looked very solid. I had one bad exhaust valve, that was it. All the timing belt parts, idler, pulleys, water pump, the belt itself, SHOWED SOME WEAR & TEAR with some minor cracking on the belt. It was about to fail according to my mechanic ( my own brother). All the cylinder walls are fine with no scratches. My engine guy is keeping this block for future project. Regarding timing belt & water pump, yes yes yes yes you must change/service them within 6 years or 90k milage WHICHEVER COMES FIRST. Toyota dealerships do offer great discounted prices for this service. I've seen all V8 timing belt service w/ water pump go for $580-$625 with free oil change included. Good luck with your replacement DR.
Take care
Ned

sixonemale

I'm in full agreement that the timing belt and water pump should be replaced at 90,000 miles or six years, whichever comes first. What I don't understand in the SC430 2006 service manual taken directly from the Lexus site, they recommend replacing the timing belt at 90,000 miles or 108 months (9 years), whichever comes first. There is not a requirement for the water pump. In 2006 did they install a timing belt made from stronger materials, is this due to the six speed transmission being easier on the motor? Not sure why they extended the length of time from six to nine years.

VVTiBob

Yes it could be the things you mentioned but I'd also suggest an experience study on the wear and tear on the actual belts themselves.

Peter_Klim

I don't think replacing te wter pump is always necessary when replacing the tiing belt.

My 02 has 55K miles.

I want to replace the belt because rubber does age over time, even with low milage, and then the unfortunate mishap that happened with the OP can occur.

The water pump, like some have mentioned here, is not listed in the service manual are requiring to be replaced at a specific milage point for time interval. Therefore I don't see the need to replace it, even more so if the mechanic inspects it and it seems to be in perfect condition and if I only put less than 4K miles on th car each year.

~7 years and ~25K miles from now my car will have to get the timing belt replaced again and my original water pump will only have 70K miles on it.

KaiserSea1

I replaced the water pump, several hoses, the accessory belt etc. none of those parts needed replacing but if you are planning on keeping the car for a while you save on labor. Changing your water pump and a few other wear items every 7 to 10 years makes sense if your just paying for parts. The OP had some bad luck, I am sure the timing belt should easily last 10 years 150K for most of us. Mine at 6 years looked new. My warranty is till 2015 so might as well do it all now.

GSteg

iTrader: (15)

You can get a brand new water pump for $110 shipped. It's a small price to pay for added insurance. While these pumps almost never fail, you might as well do it since the engine will be torn apart.

Bubba

This hit way too close to home for me as I have a 2002 with about 52,000 miles and have been contemplating replacing the timing belts for the last year or so. After typing this, I am calling around to get quotes and get it done this week. Like GSteg said, I am going to have the water pump done regardless as it is cheap insurance. I'm sure my thanks and appreciation won't help much ...

Bubba

I called for estimates, and now I'm really confused. My regular mechanic who services all my vehicles and whom I totally trust said he would NOT replace the timing belt now and would wait until about 90,000 miles to replace. He did give me an estimate of about $1000 for the timing belt, water pump and accessory belt. The Lexus dealer here in Madison also said the same thing--he would wait until the car is 12 years old or 90,000 miles. The Lexus estimate, surprisingly, was $912 including tax. Since I told him I am cautious when it comes to service and I plan on holding on to the car, he suggested the 90,000 mile service which includes idler pulleys, thermostat, radiator cap, and spark plugs for $1536. I know it's a little early to have the spark plugs replaced, but I am a little "gun shy" because the local Ford dealer wanted me to pay $3200 for the cylinder head removal when they broke a spark plug which fell into the cylinder on my truck. (The truck is a 2004 and had 130,000 at the time time, and apparently spark plugs can seize up in the cylinder. I told him it was a known problem which it is and I did get them to stick with the original estimate of $400, but I had to threaten legal action.)

Would you replace the timing belt regardless of what the mechanics say? Would you also do the spark plugs also or am I being way too paranoid? I love the car and plan on keeping it for a long time.

cjs18

This is a classic risk management situation. Unfortunately as much as you might trust them your mechanics are not likely to stand by you if your timing belt fails before they say it's time to replace it. So it's truly your call based upon how well you can sleep at night. In support of your mechanics I can tell you that when I changed out my timing belt ('02 SC at 37K mi.) it was hard to tell it from the new one I purchased to install. The only thing that appeared worn on it was that the pulley alignment marks were badly faded! There is something to what they say about it going 90K. But I'm a conservative type and I consider that both time and mileage figure into the replacement decision. To get a clue of what my timing belt might be like I inspected the serpentine belt -- it was cracked and shiny in the grooves. Although the timing belt lives in a much more protected environment I just had to get it out of there. That took roughly a day out of my life but now I can worry about something else for a while.

Peter_Klim

I dunno...

If you scroll up, you'll see I replied a few times and you'll noticed our cars are pretty much equal in age and milage.

My mechanic told me no need to replace anything. I feel sorry for the OP, but I think his situation was an isolated incindence. In the service manual for the 2020, it states to replace after 10 year or something like that, but only 6 or somehting for our 2002. Is the belt or something different or did they just change their mind?

Maybe they can inspect the belt? Can part of it be seen without having to take apart the engine? And then keep repositioning the belt until they view all of it?

I only put about 3K miles a year so if I do cahnge the belt now, and they say the water pump looks great, then it makes no sense at all to replace it. Would you replace the just the water pump on a 2010 with Zero miles (even if only $200. meaning you're not get anything done but just replacing the pump ) ? So why replace it on mine IF it is said to be in perfect condition?

sixonemale

I completely agree with CJS that it’s a classic risk management situation. My problem is that my car is 2006 but has very few miles on it. I don’t think I’ll wait to 90,000 miles to replace the timing belt, based on the cost of doing vs. the potential cost of not doing it. As far as the water pump and other items are concern, as I posted previously I would replace all items that can be easily accessed while the engine is torn apart to save on labor charges. The risk management scenario of the water pump failing is a bit different. I simply can’t imagine that dear beloved wife would be out driving on a sunny day along the coast with the top down, music up, etc., and all of the sudden the water pump fails. She would not hear it due to the music, and likelihood of hear viewing the temperature gauge clearly noting that there is a significant problem, is also unlikely, therefore, the result is a seized engine with a good timing belt. It’s best to replace both at once when you feel the time is correct, weighed against scheduled regular maintenance intervals.

cjs18

You could get a sense of what your timing belt is like by removing one of the timing belt covers. There are some other items that would need to be removed to get there, but you could make a cursory evaluation of the condition. A mechanic would probably do this work for the hourly rate but I would be surprised if he'd be willing to make any guarantees based upon his observations.

PHXSC

The timing belt is the only item in that area that is age-dependent as far as replacement goes.
The water pump, belt idler, and front seal, are mileage dependent. I didn't notice in a brief scan of the posts if anyone mentioned the front seal. If you're embracing the "change everything while I'm in there" philosophy, then you should do (or have done) the front seal as well.
A simple spin of the water pump and idler by hand and a visual inspection will tell you if either is bad. The front seal will be leaking if its bad.
I'm more of a proponent that anything done at the factory is likely better than a repair item, particularly if you're buying $100 water pumps off Ebay. You're probably pulling out a much better water pump with 40k miles on it and putting in a brand new piece of junk.
The local Yota dealers around here send flyers every month for a timing belt on a V8 for $400 that's a good deal.

PHXSC

Forgot to mention to the OP. I would keep your old block, etc., and send it to an engine builder. The weakness in these motors is the rods, and that's why they can't stand any boost without lunching themselves. Fix those rods, upgrade everything else while you're at it, slap a turbo on it!
You were gonna drop $25k anyway, right?