wcraig18

I am confused. I have a 2001 LS430.
1. Is the "timing belt" the same as a "drive belt"?
2. Is the "timing belt" internal to the engine or external wrapped around all the pully's under the hood?
Thanks, Bill

jac430

Hi Bill,

1. no, they are different belts
2. the timing belt is internal in the engine en controls the valves in relation to the crankshaft. (The crankshaft (drive shaft) is put in motion by the pistons and connects to the gearbox.)

The drive belt (= external belt) connects the pulleys of the steering pump, generator, air conditioning pump to the drive shaft (which provides the power for all these things), en can be seen under the hood.
The timing belt controls the valves and cannot bee seen. The change of timing belt is so expensive just because it is built in. A lot of components have to be removed before you have access to the timing belt.

Hope this clarifies things a bit.

Jac

GoldGS3

iTrader: (1)

My trusted independent mechanic (worked at a local Lexus dealer) told me to wait till 130K miles. I took it in at ~113K.

I don't need to take chance and stall with little kids inside.

wcraig18

Thanks for the clarification. At what inspection point does the internal, timing chain, need to be replaced??? I believe the 'driving belt" replacement occurs at 90,000 miles? Bill

jac430

That is correct Bill: 90,000 miles or 150,000 km.

Or (whatever comes first: the mileage or the time in years): after a certain number of years.
Concerning this time, there is discrepancy between various insights and there are differences between countries as well.
Some people even say that only the number of miles count.
Over here (Netherlands) I believe that the recommended interval is 8 years.

The replacement of the timing belt is quite costly. The general experience is that the "old" belt still appears to be in good to excellent shape at replacement. So that might induce a (much) later possible replacement date.
On the other hand, if the timing belt breaks you have a lot of internal engine damage, which will cost a lot more....

Jac

wcraig18

Balfor, good evening. The function of a timing belt or chain are well understood. My question is, Does the LS430 have an internal timing CHAIN? My sense is the LS430 does not have an expensive timing CHAIN, but rather a less costly alternative external to the engine call the timing BELT. Is this correct? THX, Bill

wcraig18

jac430, thanks. This is frustrating. I think of an internal engine part as a CHAIN (Made from metal) and an external engine part as a BELT (Made from rubber). Is this correct for the LS430. Thanks for your patience. Bill

jac430

Hi Bill, your thinking is logical. But unfortunately not applicable to the LS430.

My previous car (Renault Safrane V6 from 1992) had a timing chain (metal).
The advantage of that is, that it (in principle) never needs replacement. At least not for 300,000 miles or so.
The disadvantage of a chain is that it produces slightly more engine noise. A toothed belt (rubber with high-tensile fibers) is just quieter.
I think that is on of the reasons that Toyota used a belt in the LS V8 engines, although I am certain there are other considerations, since most engines have a timing belt instead of a timing chain nowadays. Belt-systems are a lot cheaper for the car manufacturer than chain-systems, and that is likely be the major consideration to use a timing belt.

My LS430 is 7 years now, which means that next year I have to fork up a large amount just for the timing belt replacement.
My Renault obviously never had these costs in the over 18 years of its service.
For my taste, they could as well have used a timing chain. If the engine is well designed and the engine-bay and the cabin proper sound-insulated, a chain would have saved us all a lot of costs. The V6 of Renault was quiet enough. (Although they changed that V6 later on and used a belt as well, creating a worse engine in the process....)

Hope this explains it a bit.

Jac

Nixsun79

Is there anyway to check if the timing belt has been replaced? I purchased a used 04 with 89k miles on it. The thing was served by lexus at every interval but the report on the lexus site just says "recommended service completed" or "75k mile service completed"

jac430

If the timing belt is replaced there could/should be a sticker indicating the mileage at which this is done.
If such a sticker is not there, just phone any Lexus dealer and they can look it up for you.
It is a good thing to now indeed!

Jac

Nixsun79

Thanks Jac, Do you know where the sticker would be placed?

jac430

I have only seen it once on a LS430 I was interested in. I can't remember precisely, but it was somewhere on top and near the front of the engine, and clearly visible.

Before I bought the LS430 I now have (a different one from the one I saw the TB sticker in), I phoned the local Lexus dealer, and they could look into the service history of the car (which has been serviced at a different dealer). Despite the fact that this local dealer is extremely unfriendly and the car was from a private seller, they still checked the service details for me.
If in doubt, just call any Lexus dealer and ask when and at what mileage the timing belt has been replaced.
I suppose that is the only reliable source.

Hope this helps a bit.
Jac

wcraig18

Thank you. Perfect answer. Cheers, Bill

atmijlin

I just bought a 2005 ls430 at 107k. It did not have the 90K timing belt service. my question is does it just need the belt or it also needs tensioner, water pump.. etc..

wcl77

I just purchased an 02 with 73k. I called a friend who is a lexus mechanic who told me if were his car he'd change the belt and water pump. age can be a significant factor as with miles. I'm taking the car in today.