Piston rings?

  • I have 1995 V6 1.8 limited edition SE Equipe, very few around with turquoise flash along the sides.Mileage 135000. Problem began 1month ago with unusual non start. Had service with new plugs HTleads oil/air filter etc. Drove much better but white smoke (condensation)??all time, not just when cold.Began misfiring so thought faulty HT leads, replaced them but performance got worse few days later, now burning lot of oil, blue smoke, misfiring, loses power then resumes before spluttering again , much better when very hot but not confident to drive it. Oil in spark plugs, have dried them off but oil returns. Thought at first it rocker gaskets but mobile mechanic and advice on phone by engine rebuilders convinced it piston rings. Found 2nd hand engine import from japan approx £400 or can get 2nd hand from salvage& parts search on net or should i have my engine rebuilt? All expensive so need advice as to best route to go. Minimum quote approx £500 labour only, to remove and refit another engine. Car not worth this amount but as very few of this model still on the road would like to repair if possible. Can anyone help please?

  • Welcome,

    Does it overheat? Losing coolant?

    You should have blue smoke with rings really rather than white as well. Have you done a compression test?

    Perhaps someone on here will have a k8 they removed for the 2.5 swap they could sell you cheap. I have one but I'm in Northern Ireland so it's about £90 on a pallet delivery before you start. You could also consider a 2.5 swap yourself if that interests you.

    Good to see someone caring enough to keep it running and welcome


  • Thanks for reply but no not losing water or coolant. Can i get a compression test done at home as so reluctant to drive it. What mileage on your engine? Think i have K8ZE on this model.

    1. Oil in the spark plugs will probably be rocker gasket 99% of the time on the MX-3. You can confirm by looking down the sparkplug holes with a torch, with the spark plugs still in, if there is oil ontop of the spark plug its the rocker gasket.

    2. Most likely cause of blue white smoke is the head gasket not piston rings, though it could be rings. You can check this in several ways:

    Step 1 check for oil and water mixing

    • Look under the oil filler cap, is there any gunk under there (light brown, creamy colour)?
    • Look in the coolant expansion tank, any brown deposits in there? has it changed colour? any irridesant colours / oil floating on top?
    • Check your water level to see if it has gone down.
      Step 2 check for air from compressions in the sump (if rings are worn air will be forced past them on compression and end up in the sump)
    • Simply pull out the oil dipstick and with the car running look to see if there is any smoke coming out of it.

    Step 3 check for air in the water

    • turn on can and let it run for 10 mins, is it running at a higher temp than normal?
    • Is there any constant air bubbles in the expansion tank? If so how many?

    I would do the above simple checks then post your results here so we can advise you before doing any of the advanced checks below.

    Coolant exhaust air check

    • you can get the coolant in the expansion tank checked to see if it has been in contact with exhaust gasses, meaning a head gasket or cylinder head fault.

    Compression Test

    • Get hold or a compression tester and test compression on all cylinders. If the readings are significantly lower than they should be (someone help me out here I can't remember what they should be on an MX-3) it means either the rings or the valves are leaking air by them.
    • To test if its valves or rings simply put a very small amount of oil down the sparkplug hole then do the compression test again. If the compression reading gets better then it is the rings.

    Cylinder leakage test

    • This basically fills the cylinders with compressed air and a guage shows the leakage rate and will tell you if the cylinder leakage is acceptable or too high.
    • But if while the test is being done you take out the oil dipstick and see if the air is coming out there it will tell you if the rings are letting the air past.
      Then put it back and take off the oil filler cap if there is air coming out its the rings. While your doing the test you might aswell listen at the air filter, if there is air coming out then the valves are leaking. If there is air coming out of the exhaust pipe then the valves are leaking. Look in the coolant expansion tank if its bubbling then the head gasket is gone.

  • good post admin. I'll also add, if the oil is on top of spark plugs/bottom of HT leads, then certainly the valve cover gaskets. If it's on the electrodes (blackened inside the combustion chamber) then it's either rings or valve stem seals or guides.

    You can buy a compression tester in halfords. It's fairly easy to do yourself:
    -take out all spark plugs
    -disconnect the two fuel rail electrical plugs
    -screw in compression tester into first spark plug hole
    -hold open throttle body and crank the car over

    • usually about 6-8 cranks should see a decent reading

    For a k8 ze I'd be looking around 180-210psi. It's more important that they're even than exactly a figure. I can't remember the exact acceptable range though.

    If it's very low, eg 100psi, try dropping a bit oil down and see if that pushes it up higher. If it does it's very likely the rings.


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