Do Not Sell My Personal Information Jump to content


New Owner Advice Timing Chain


Recommended Posts


4 minutes ago, NemesisUK said:

I thought if it was a chain, not a belt, there is no requirement to change it unless it's rattling and showing signs of stretching? 

+1 to that, exactly so.

Link to comment
Share on other sites

No issue with mine at the moment just curious.

Had cars in the past that have specified it to be changed at certain mileage etc. (belts as opposed to chains)

Thanks for the input. 

Link to comment
Share on other sites

The most critical thing affecting timing chain (and tensioner) life is good quality, clean oil. If you use the correct oil (fully synthetic 5W-30) and change it at 5K mile intervals from now on (twice as often as Lexus service spec) they will last more or less indefinitely - 200K miles or more.

And by then, it is unlikely to be an economic proposition - it's a pretty expensive job to do yourself (think 4 figures) and will cost well more than the car is worth at 15 years or more to have done professionally.

  • Like 1
Link to comment
Share on other sites


1 minute ago, johnatg said:

The most critical thing affecting timing chain (and tensioner) life is good quality, clean oil. If you use the correct oil (fully synthetic 5W-30) and change it at 5K mile intervals from now on (twice as often as Lexus service spec) they will last more or less indefinitely - 200K miles or more.

And by then, it is unlikely to be an economic proposition - it's a pretty expensive job to do yourself (think 4 figures) and will cost well more than the car is worth at 15 years or more to have done professionally.

great advice thanks!

Link to comment
Share on other sites

11 years on, the case of Lexus is chain snapping is yet to come. I am sure some guys in US had covered 300k miles without issues. I believe eventually we will have case of snapped chain somewhere, but at the time car will be worthless anyway.

Actually, I am quite surprised by BMW topic, I though by now most of engines are non-interference and valves does not cross the patch of pistons anymore not in BMW diesels that is... 

Link to comment
Share on other sites

A friend of mine has a 2008 118d BMW that had this timing chain problem.

What drove BMW to install the chain at the rear of the engine is beyond me.

Anyway, his car also needed a new dual mass flywheel, 2 injectors and engine mounts at the same time.  Total bill was £4500!

Link to comment
Share on other sites

I didn't actually mean the position of the chain contributed to its failure :smile:

What I was bemoaning was the fact that it meant taking the engine out to change it rather than just the front timing cover.

Link to comment
Share on other sites

It's not really snapping that's the issue at big mileages (although it can happen) - it's stretching of the chain, along with corresponding wear of the tensioner and the sprockets. That leads to excessive noise. This problem will rear its head more and more with stupid extended service/oil change intervals - the wear is largely caused by ineffective lubrication when the oil gets contaminated.

I'll say it again - frequent oil changes!

(BTW - IS250s have three chains - the main one which drives the intake camshafts and two small ones, one for each bank, which drive the exhaust camshafts from the intake ones.)

  • Like 2
Link to comment
Share on other sites


I agree John.

I personally think it is madness to service a car only once every 20k miles or so.

Yep, it has been a while since I have heard of a chain snapping.  In the case with my friend, the chain stretch had worn out the sprockets on the cam gears as well, and it had jump a tooth or two, causing a misfire.

Still, it wouldn't be a huge job if the chain can be removed from the front without having to remove the engine, unlike the affected BMW's.

Link to comment
Share on other sites

14 hours ago, Shahpor said:

I didn't actually mean the position of the chain contributed to its failure :smile:

What I was bemoaning was the fact that it meant taking the engine out to change it rather than just the front timing cover.

That is because "by design" it should have never be replaced, but reality is different as we know.

Have anyone actually heard of one snapping on IS250 yet?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share



×
×
  • Create New...