After five years of regular use, yearly oil change and regular service without any problem with oil levels my car has just used 1ltr of oil in just over 1200 miles.
We have just returned from a brief holiday in France and it was necessary to top up the oil when we arrived and again when we got home.
We did not travel at any great speed, maximum 60mph but most of the time rather less as we chose to drive most of the time roof down, the journey from Calais to our holiday base was 190 miles each way added to the 150 miles each way from our home to Dover.
There is no sign of a leak so I guess the engine must be burning oil, does anyone else have the same problem or is this to be expected when using the car for any distance?
Unfortunately, 1.8s are known to turn into oil burners; the most common cause seems to be sticking oil scraper rings. Mk2s seem to be most prone, but it can happen to Mk1s, even at quite low mileages. An interesting discussion on the subject:
http://forum.miata.net/vb/showthread.php?t=461565
Thank you for sending me the link which describes the oil scraper ring problems, the cars that were featured were Mk2 my car is a Mk 2.5 with 45k miles would my car have the same problem/cause as the other cars decribed ?
Also what is PCV valve, what does it do? and how do you check for problems?
Basically the same engine. Loss of oil could be due to lots of reasons, including a dud £2 PCV valve on the camcover.
What is the PCV valve? what does it do? and how do you check for problems? is it a difficult job to replace?
Basically, its the Positive Crankcase Ventilation siphon to recirculate
vapors from the crankcase and route them back into the intake manifold to reburn them in the engine.
They can get clogged, but you can unclip it and soak it in petrol or white spirit overnight and refit but they are so cheap it’s best to get a new one.
There is a ball bearing one way valve (or something 
) inside, so remove it and good it a good shake. If you hear the bearing rattling it’s good, if you don’t it’s likely clogged up a bit.
I don’t know how it makes for excessive fuel consumption…but it does. I’m not that technically competent myself.
I’d be disappointed if the oil-scraper rings have gone at such low miles but it’s not impossible as AT says.
I’d be very surprised provided you have been careful with oil changes…so think PVC first.
An example:
It just unclips from the offside camcover.
TBH, a litre every 1000 miles or so is not drastic. My Mk1 1840cc engine did that for 7 years & around 45000 miles before the oilrings cried enough recently.
On the other hand, my wife’s 02 Sport (bottom end basically the same…the engine…not the wife!)) at 74,000 miles uses none at all, and it abused with short journeys… BUT…it gets an oil & filter every 3,000 miles or twice a year.
Hope that helps some more Paul. Let us know how it goes?
Very many thanks for the detailed reply to my oil burning problem, I have a Haynes Repair Manual that shows the PCV Valve very clearly (that’s a first) they state that the valve should be replaced every 30k miles or 24 months!!!
Needless to say I have now ordered a new PCV from MX5Parts together with a new Grommet so will report back when both are in place.
One more question do you run your cars on normal, semi or fully synthetic oil and do you have an opinion on pro’s and con’s?
Thanks again for the advise and I won’t tell the wife!