sarah

When should the RX300's timing belt be replaced? what's the cost?

I still have another 20000 miles left in my Lexus extended warranty. Obviously a broken
timing belt will not be covered, right? What is likely to happen if it breaks while I'm driving?

Thanks for any info!

rxdriver

The timing belt isn't due until 90,000 miles.
If the belt were to break - which is VERY rare if changed as scheduled - the engine would cease to function until it was fixed.
Often, the timing belt isn't wearing out at 90,000 miles, and I'm sure people can post stories about it lasting much longer. But, better safe than sorry since it is such a critical part.
You'll see in the maintenance guide that inspecting the drive belts (which includes the timing belt) is part of every 15,000 mile service. Assuming the tech is really inspecting it, any premature wear problems would be self-evident and would be caught in time to prevent a breakdown.
Changing the timing belt is a very labor-intensive process, so it's usually up around $400-$500 of labor for a $50 part. Because of the labor involved, many people also replace the water pump at the same time because you have to remove the timing belt to replace the water pump. The water pump isn't due at 90,000 miles, but again, it's more of a preventative thing.

HarrierAWD

The RX300's timing belt should be replaced at 90K. It'd cost about $400 at Lexus, $300 or less at Toyota. It cannot be inspected unless the engine cover is opened, so it is not checked during routine maintenance.

While it is possible that the timing belt can go over 200K without breaking. A worn and stretched timing belt can cause other engine issues. It's better to have it replaced per schedule.

Lexmex

The timing belt is in a pretty protected location...not that it couldn't break, but I agree this is very rare. I would only add to the other comments, that you should at the same time as getting your timing belt and water pump changed out to also change the accessory belts (the ones visible) as these are not as protected and will get worn over time.

HarrierAWD

I think that I can trust Toyota/Lexus quality and not replacing my water pump at 90K. (Maybe at 180K.) Water pump fails because gunk buildup in the coolant. The gunk overworks the bearing and eventually it seizes. You'd see it often on Ford & GM vehicles. My RX's coolant reservoir is still prestine after 4 years and 60K miles. Compared to my previous GM vehicle with gunk and residue after only 6 months. It's normal according to Mr. Goofwrench. Little did I know.

A friend has an '88 Accord (yes, 1988) with original engine & water pump. Still commutes daily with it.

mhc0725

Water pump replacement is purely preventive, not required. I changed my RX timing belt overkill at 60K as part of the dealer's 60K maintenance ($1400) and waterpump was not included and 30K later, so-far-so-good.

Water pumps are funny, they sometimes go or they never go. Knock on wood, my '92 Integra GSR has 210K on it and still on original water pump after three timing belts. Original engine too with no rebuilds of anything. With that said and written, it'll probably break down tomorrow... ha ha

Dx3

iTrader: (13)

Is the RX interference or non-interference?

Jonny

Lexmex

non-interference.

LiqrSicc

^^^ I hope so. I remember a thread here a while back where we couldn't figure it out since there were multiple sources that had different answers. I'm agreeing with you though, LexMex, you seem to know a lot about the RX

Lexmex

I think that whole bit started because one of the more known timing belt manufacturers erroneously listed interference on their site.

Keep in mind, unlike the alternator/PS belts you can visibly see, the timing belt is in a much more protected area from road debris and the like. Doesn't mean it can't happen though.

sarah

so... I'm taking it in next week to have the timing belt replaced...

will probably have the water pump replaced as well. $300 extra, if done with the belt service
($800 if I have it replaced when it fails)

Just out of curiosity, what actually happens when the water pump fails? Does the
vehicle overheat and blow stearm?

Thanks!

Lexmex

Well, it will overheat and you might see some steam, but in the most likely of the failures you will see a pool of coolant underneath and likely hear a high-pitched chirping sound. The drop in coolant level will definitely be noticeable. The real damage should lie around the cylinder area.

WooDog

What does it mean if rx300 belts are non-interference? Does it mean the engine won't seize if the timing belt does break?

JAB

I believe that information is wrong, and that the engine is in fact 'interference' which means that if the timing belt breaks it is likely that the pistons will collide with the valves, causing major damage.

I recently replaced my timing belt for the second time; first at 95K, this one at 215K. Belt looked brand new. Also did water pump, tensioner, idlers, thermostat, accessory belts, and cam and crank seals. Had previously done plugs and valve cover gaskets.

kalali

The timing belts tend to have a very long life if there are no leaks, coolant or oil, from the surrounding areas/components. A leaky water pump, even a minor leak, can shave a good chunk of life from the belt. As for the interference, there are some that say, my belt broke and no engine damage was done. They were simply lucky that the belt broke at a spot where the valves and the pistons did not kiss...A second or two later would have meant a complete engine overhaul.