MK3 possible piston rings?

  1. My model of MX-5 is: Mk3
  2. I’m based near: _Gloucester _
  3. I’m looking for technical help or recommendations on: smokey engine.
    I’ve just bought a project 2006 1.8 NC with only 60k on the clock.
    It’s in immaculate condition apart from the engine burns oils like any thing.
    I knew this when I bought it, so its not issues.
    My question is, what is the usual cause of this on NCs? is it likely to be the piston rings or I have read that the PCV can fail and cause the same symptoms.
    I’m more than happy (and capable) of sorting the rings out if needed, just don’t want to start stripping it down if there is a easier more common solution.
    Thanks all.
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Hmmm, no matter what engine in what car.
With a smoky engine, i.e. burning oil you are looking at a multitude of faults.
Worn piston oil rings which could be worn stuck or broken, excessive bore wear, worn valve guides,(part and parcel re the stem seals), worn valve guide oil seals, the actual head gasket and as you say the PCV. (Just the majority of potential problems).
60k in an engine miles wise is nothing really, but clearly something is amiss.
Unfortunately sometimes one thing leads to another and you would be best to look at them all.
It’s false economy to just do/look at one.
Just an opinion, but potentially a lack of regular oil changes.
A full engine diagnosis would be my best advice.
Good luck. :slightly_smiling_face::+1:

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Thanks Scarletpimpernel,
After driving it 100 miles today back home after buying it I have ruled out a number of things ie head gasket as the temperature is spot on and it doesn’t lose water.
Also it smokes on acceleration rather than overun so probably not valve stem seals.
At 60k I would like to think the bores haven’t worn out, but as you say “potentially a lack of regular oil changes.”

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Roger that.
As you say do the PCV route first.
Failing that, get it apart and check out those oil rings (and all) and see where you are.
“Might” be a simple quick fix. :man_shrugging:
Only 60k and lack of use, rubbish maintenance might just be the route of the problem.
Would be interested in the outcome. :+1:

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Compression and leak down test, check spark plug
condition then borescope should determine where the problem lies. If bore scored then you may wish to consider a replacement used engine. You might look at a 2l but will need to change the ecu and engine wiring. If you are near Sheffield then Paul Roddinson is your man.

I did consider a replacement engine but then may end up with something that fails in the near future and be back to square one.

At least if I have to overhaul the one I have I will know it will last.

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The oil control rings on the pistons are gummed up and stuck together, go straight to that and ignore anything else.

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Has anyone had the pistons out of 1.8 NC?
The reason I ask is that I’ve just checked the Haynes manual before starting the job and found this…

I’ve found rings and big end bearing for sale online so surely this can’t be right??

Haynes tho innit bruv :grinning:

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yes you can take pistons out after dropping sump with head off and removed from top.

rings and shells via ebay shells 59.00 rings 100 a full set

just done mine burning oil like no tomorrow . pcv was ok and valve seals ok

hope this helps

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Some MZR engines use a lot of oil and some owners don’t realise until the red oil pressure light comes in, by which time the damage is already done. But check the simple stuff first: PCV then dry and wet compression tests.

It isn’t in any way a bad engine. Reports of Duratec problems on Fords (a vastly bigger sample) mostly relate to ancillaries like the intake manifold or alternator, not the block or head.

Hi Scottyy,
Thanks for the reply.
Mines all done and back on the road now. I dropped the sump and took the head off as you say. Spent a day laying on my back under the car with oil dripping onto my face :confused:
I fitted 1x new piston as No 3 had picked up. Honed out all the bores, fitted new rings and big end shells and threw it all back together.
5k miles down the road now and a couple of oil and filter changes, it runs like a dream. The oil level doesn’t drop one millimetre at all.

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Well done!

Great News sorry never looked at date was a while ago lol.
Just putting mine back together will be on road by weekend fingers crossed all goes well .

Nice to hear it fixed it.
Can I ask where you got the parts ( rings/shells/piston ) from ?

Yep sure, piston off eBay. Rings and shells from Autolink

Good luck :crossed_fingers:
I ran mine in softy ( not going over 3k revs) for about 1000 miles then dropped the oil and filter again. Build engine revs up slowly after that - now normal.
(Sorry hopefully not trying to teach you to suck eggs)

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Thanks for that m8 will do same as you did it worked lol

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She back on road now no smoke and rattles all good. done 100 miles now and oil level right on high line whoop whoop .

Got my rings ebay and shells . shells was £59.95 and rings £100

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Thanks for this forum query Richj870… I have just bought a project MX-5 2006 1.8 and your engine issues sounds identical to mine although I haven’t been able to take it for a long or short ride.

It has a bad rattle when it starts from cold onl and now that I topped up the oil so that it reads on the dip-stick, the engine smokes at approx 2000 rpm, so I suppose that was why the oil was so low (burning oil)

I was wondering if it was the piston rings and therefore a bigger project than anticipated. I hope you have success and I’ll look forward to reading your results before I go down the road of buying a replacement engine.