Engine Drive Belt

[Speedwell]

On the service schedule it states this belt should be checked at 6 years/60k miles and annually thereafter.

My IS250 is 8 years old but only 47k miles and a fair assumption would be the belt has never been replaced,so I was going to have this done at the next service.

However a quick look on eBay shows that as well as the belt at about £25 there also a belt together with a tensioner kit at about £100.

So I'm wondering if the tensioner should be replaced at the same time as the belt?

[scudney]

I would replace the whole lot for peace of mind including water pump

[Speedwell]

I know water pumps can be a weakness on VAG cars but on the Lexus 250 engine ?

The problem is that on any 8 year old car if you want total "peace of mind"you can end up replacing everything.

However,I agree that pro-active replacement of known weaknesses on a specific model is desirable.

[scudney]

Personally I think it's good practice and makes sense having the lot done,only going to cost you for extra for water pump but no extra labour charge,if you ignore it and the pump goes at a later date ends up costing you more.Not a comparison but when changing discs and pads makes sense doing it in pairs,no point changing one disc and pad and not the other.

[goldtop]

I'd expect that adding a water pump change would add some extra labour - hoses off/on and draining/refilling coolant at least, no?

[scudney]

Not as far as am aware stand to be proven wrong though

[Speedwell]

I was looking for specific info as to possible weaknesses/premature failures relating to the belt tensioner (and water pump) of the IS250 engine.

If none are known then,bearing in mind the relatively low mileage,in replacing the belt the bearings on the pump and tensioner will be checked for excessive play or other apparent faults and if nothing appears wrong then I doubt if replacement can be justified.

Lexus rate the coolant to last 100k miles so It would be strange if they did not expect the water pump to last at least as long.

[ColinBarber]

I would have thought the belt would also be rated for 100k miles??? Check/inspection isn't the same thing as replace.

[scudney]

Bottom line is the choice is down to you as to what you change or don't change or for that matter when you change them,they are guidelines which can either be ignored or adhered to.

[Speedwell]

I would have thought the belt would also be rated for 100k miles??? Check/inspection isn't the same thing as replace.

Agreed.

I am influenced by recent experience with my 8 year old 350z....only 25k miles but the belt was replaced because of ageing signs.

If the belt looks fine on the Lexus I'll leave it ,but any doubts I'll change it for the costs involved,

Judging by the response it seems that the belt is not a frequent change item,nor are the tensioner/ water pump,since no-one has come up with anything specific they have done (or had done by a Garage) on the IS 250 engine.

[normski2]

Stand to be corrected...of course...if I'm mis-informed. Thought the V6 250 was a chain timing belt? The 220d certainly is a chain timing belt. But there are ancillary multi-v drive belts to be changed at intervals on both 250 engines.

The series 1 is200 had a timing belt that needed changing at set intervals, and that did involve the tensioner being done. Had it done on my is200 sport that I used to have.

[Speedwell]

Stand to be corrected...of course...if I'm mis-informed. Thought the V6 250 was a chain timing belt? The 220d certainly is a chain timing belt. But there are ancillary multi-v drive belts to be changed at intervals on both 250 engines.

The series 1 is200 had a timing belt that needed changing at set intervals, and that did involve the tensioner being done. Had it done on my is200 sport that I used to have.

My understanding is that the IS 250 has the cams driven by a chain and not a belt and so is,in theory ,maintenence free in this respect.

But...I (and others I assume) have been referring to the rubber external belt that drives the alternator and water pump.It may do other things,I have not had a good enough look yet due to the fact that the engine is almost totally hidden under plastic covers.It may also drive the pas but not If the power steering is electric,which I think it is.