My Tappets maybe ?

[Malc]

very odd, the first time ever the other day I thought I could hear my tappets, well, tapping very slightly .....  never before nor since thankfully

Remember the sound from many years past cars .......... in olden times ...... or maybe a stone in tyre tread BUT it certainly sounded like tappets

Your thought s guys ?

Thanks

Malc

[runsgrateasanut]

Someone nearby using a Kango Electric  Hammer,  maybe?

[First_Lexus]

54 minutes ago, Malc said:

very odd, the first time ever the other day I thought I could hear my tappets, well, tapping very slightly .....  never before nor since thankfully

Remember the sound from many years past cars .......... in olden times ...... or maybe a stone in tyre tread BUT it certainly sounded like tappets

Your thought s guys ?

Thanks

Malc

Tiny elves making shoes using an anvil. I owned a Metro back in the day and that was the only reasonable explanation for the noise the engine made…

[Mikaelse]

4 hours ago, Malc said:

very odd, the first time ever the other day I thought I could hear my tappets, well, tapping very slightly .....  never before nor since thankfully

Remember the sound from many years past cars .......... in olden times ...... or maybe a stone in tyre tread BUT it certainly sounded like tappets

Your thought s guys ?

Thanks

Malc

If you read up on LS400 there seem to be some that do report tapping noise from some valve clearences that has become a bit large over time on high mileage vehicles. Often from only a few valves it seems. In engine design for the last 30 years the valve seats are a very hard ring insert and the valves also have a hard wear layer to cope with unleaded fuels. If all contact surfaces are hard material adjusting valve clearence may never be needed even though there are no self adjustment in  the LS400 at all like many other cars have these days.

Adjusting valve clearances on the LS400 is a camshafts out job... No fun at all and you need special shims with custom thicknesses.  

Slight tapping noise within reason is not risky for the engine. The opposite, Too little clearance is much worse. Then you can ruin things fast and you will get no early warning. I have the impression that too tight clearance very sedlom is a problem hence slight tapping as a warning can be expected if attention is needed. I have never checked clearance on my two LS400 with 200.000 km. 

[Howplum]

A little light reading:

https://us.lexusownersclub.com/forums/topic/19119-90-97-owners-check-your-engine-valve-clearances/

[Malc]

OMG reading the above ...  I'm quite certain now that I must have just imagined the noise .. the alternative is mind blowingly challenging and I cannot for the life of me think the job involved checking / changing will ever be done under my watch ...  237k miles ( just approaching ) so there's much to wonder about and things to just be unusual for most Members on here to ever have come across ....

I shall leave well alone and enjoy the rare noise if it ever reappears ....  maybe just over next Christmas with the elves !

Thank you all for your thoughtful input . I'll check the local kango hammer user for sure 

Happy New year to one and all

Best wishes

Malc