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‘97 Mazda MX5 MK1
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Discussion Starter · #1 ·
Hey everyone sorry in advance as I’m sure there’s countless posts like this but I’d appreciate your input please, as the title suggests I’ve got a not so lovely noise coming from my mx5 which with it being an older car isn’t much of a surprise. I know it’s not uncommon for mk1’s to develop lifter tick and a simple oil change typically fixes that but I’ve had a few people hear the car in person and they suggested it may be rod knock.

Some quick points to note:
  • the noise goes away after driving, sometimes within a few minutes other times can take up to 10 mins or so
  • noise increases with rpm

I’ve posted two videos on YouTube, one being a cold start where you can hear the sound loud and clear:


and the other simply showing that the noise had gone after a 20 minute drive:


P.s. I’m aware of the oil on the cam cover I haven’t got round to sorting it out, please don’t shame me for that 😂😂
 

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Hiding from the Ayatollah or making Full Metal Jac
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Completely normal on older MX5s especially if you or a previous owner haven't run it much, or the oil changes have been 'patchy'. Warm it up. Drive it hard. I've got a 1989 car on the original lifters and it ticked a bit after I left it a few months but after regular driving it's all good. Change the oil to something good quality (fully synth) and it may help it.

The cause is the lifters, which are filled with oil 'Hydraulic Lifters' - they maintain their size based on being fed oil by the car as the engine runs and then holding that oil load between drives. I don't know the precise failure mode but either the access hole to allow oil in gets a bit clogged or the check valve that's meant to keep them full gets stuck open, or the plunger gets stuck inside the lifter. Anyway whatever the cause, the lifter ends up being not as big as it should be, the gap between the lifter and the cam ends up a bit bigger than it should be until the lifter pumps up again and the gap goes down to the correct size. The ticking is the cam whacking the top of the lifter with a greater gap than is normal. The lifters and cam are hardened and lubricated so it isn't high risk.

If you're feeling adventurous you can clean replace or clean the lifters. It's ''involved''. There's a lot of info on YT about doing that.

I recommend the oil change and higher RPM driving which may clear it up.
 
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‘97 Mazda MX5 MK1
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Discussion Starter · #6 ·
Thanks for the replies! Especially thanks to atlex for going over it in detail I understand it a bit better now.

Good to know it’s more than likely lifter tick then and nothing too serious, was worried about putting in the money to do the car up for it to then die on me immediately so this has put my mind at ease 😅
 

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Im not a big fan of engine flushes but ive used in past way back on a noisy lifter tick engine and sorted it when a fresh oil change did not.

Sent from my SM-N950F using Tapatalk
 

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VVT swapped NA & TD04 turbo NB
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Here's a story about how I killed my first MX-5 engine. She was a high mileage girl and she was all working and I was keen to do some preventative maintenance.
I'd heard good stuff about flushing an engine to de-coke the engine and release more power, but this was before I really knew anything at all about cars.

Well it did just what it said on the tin, it de-coked my engine and suddenly all the hardened coke that was sealing up wear from poor maintenance by previous owners was flushed away :D

spot the issue :D

Automotive tire Alloy wheel Rim Wood Auto part
 

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VVT swapped NA & TD04 turbo NB
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gudgeon pin circlip has done a runner & the gudgeon pin has met the bore?

rebuilt time with rebore or replacement cylinder block....

Rich.
Aye exactly, but must have been that way for some time and sealed itself until I run a bottle of cleaner through.

I went with the less time intensive option of using a breaker engine at the time.
 

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Just curious, what were the symptoms of this wear after the cleaning? Loss of compression, increased oil consumption?

Sent from my motorola one using Tapatalk
 

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Just curious, what were the symptoms of this wear after the cleaning? Loss of compression, increased oil consumption?

Sent from my motorola one using Tapatalk
Massive oil consumption, lots of smoke on over-run from the exhaust
I actually assumed it was my valve seals until I'd got it apart to inspect.
 

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Massive oil consumption, lots of smoke on over-run from the exhaust
I actually assumed it was my valve seals until I'd got it apart to inspect.
That's really interesting. I should run a bore scope down my smoker. :D how heavy was the over-run smoke and at what rpm ? :D
 

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That's really interesting. I should run a bore scope down my smoker. :D how heavy was the over-run smoke and at what rpm ? :D
I'm afraid I don't remember, it was such a long time ago, I didnt have any experience, in hindsight a borescope would have been used lol

I remember it being quite a lot of smoke though, enough that I got a call from a friend telling me
 
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