Mx5 mk1 1.6 tapping sound

[j4ck100]

Hi everyone

Just in the process of bringing my mx5 mk1 1.6 out from winter hibernation (bit later than I’d have liked but weather hasn’t been great!)

Fired her up and she started on the button but there’s a pretty significant tapping sound coming from the engine, it was present lightly when she went in in November but seems to have gotten worse

I’ve read that sometimes a good service can cure this but my dad is convinced the valves need adjusting - what is the story on these engines?

Thanks a lot
Jack

[Oldandslow]

Car has hydraulic valve lifters. No adjustment. After sitting they'll need a while for the oil to warm up and circulate so they sound tappety. If you want to do something treat it to an oil and filter change with a good quality oil. Maybe a flush and change.

[anonymous-user]

All mk1s I've had have done this, as said its the oil filled lifters and the little oil-filled piston in one will be stuck so there is a gap and it rattles. Normally a full hot to cold cycle will unstick it, but you can also try adding Wynn's lifter additive to help in future (as well as regular oil changes):

https://www.amazon.co.uk/Wynns-76864-Hydraulic-Lif...


Article here showing what they and how they work (and how to deep-clean them if you're happy to pull things apart):

https://www.miata.net/garage/hla/cleaning.html

Edited by anonymous-user on Monday 20th May 08:55

[cwinterb]

IMO best quick fix is fresh oil and an Italian Tune Up. Mine never idles more quietly than on a trackday after a good thrashing.

Make sure you drive it far enough (20 miles+) and hard enough to put it through a proper temperature cycle. Round the block is not enough. I have got an oil temp gauge and cooler in mine (behind the rad but no thermostatic take off) and it takes 10 miles of gentle road driving to get the oil up to temp, will be a bit quicker without a cooler I guess...

[J8 SVG]

Mighty Car Mods have documented this fix in their videos very recently (It's an evo but the same principle) https://www.youtube.com/watch?v=TBuUTWpNWC0

They mention in this video doing the same for an MX5 but I can't find the old video

[mrciarano]

Valves def don't need adjusting - the engine has hydraulic lifters that do this automatically!

That said - the others are right with changing the oil after it's been sitting a while, kind of normal behaviour with HLAs that have been sitting for a while. Best advice as said is use some lifter additive or use some engine flush, then change the oil and filter if the car has been sitting a while - should clean out most of the gunk after a couple of heat cycles from the HLAs.

If it's bad and it persists after an oil + filter change and a couple of heat cycles, best to either service the lifters (good article here https://www.miata.net/garage/hla/cleaning.html ), or if you value your time a little more just grab some new ones altogether, iirc autolink has them listed fairly inexpensively.

EDIT: whoops someone beat me to it

JimSuperSix said:

Article here showing what they and how they work (and how to deep-clean them if you're happy to pull things apart):

https://www.miata.net/garage/hla/cleaning.html

Edited by JimSuperSix on Monday 20th May 08:55[/footnote]

[footnote]Edited by mrciarano on Saturday 25th May 17:55

[j4ck100]

fixed with an oil change and a good italian tune-up, thanks all