Hi,
I keep having to top up the oil! Thereâs no obvious leak, and no clouds of blue smoke when I pull away - does this engine burn oil when pushed hard? I do the odd track day, and work it quite hard.  The car came with a bottle of oil in a case with dipstick wipes etc, presumably from new, so Iâm wondering if the high tax bracket is because it is designed to burn oil? Or do I have a problem?
The first question to ask, are you reading the dipstick correctly, not such a simple thing to do on the Mk3 engine?
What year is your car, how many miles it done and how much oil do you think it burns in say 1k miles?
I did read somewhere that NCs which are pushed a lot can use some oil & thatâs normal? Which might be the issue with yours given your track days. Also in my experience engines can often start to burn oil at relatively high mileages - how many miles has yours done?
Mineâs never used a drop in six & a half years, the level stays exactly the same & Iâve never had to top it up- & I do have a bit of fun occasionally! But then again the mileage is only just a shade over 30K & it was carefully run in when new.
The most important thing of course is to keep the oil up to âMaxâ - or very slightly above - on these engines because running with even slightly low oil will wreck the bearings. Sounds like youâve got that covered!
âŚit has done 88k. I had it serviced, did a track day and found it had dropped to âminimumâ . I think Iâm reading the dip stick correctly: thereâs a flat section with two marks across it which I assume are âmaxâ and âminâ. I was hoping they had been careless with the service, and added nearly a litre to bring it up to âmaxâ. Since then, another track day and it needed 200ml to take it up to âmaxâ, and itâs dropped a fraction since, after 2k of road use. The last car I had that used oil like this was a tuned Morris Minor (!) back in my youf, but I reckon more leaked out than burned . . . .
âŚitâs an '07 Roadster sport. It seems to burn a tiny bit in 1k road use, and maybe 20ml in 1k if this includes a track day, assuming the first low reading was caused by careless filling at the service.
Mine uses very little if any between changes in 6k miles, itâs on around 65k miles.
20ml doesnât seem much in 1k miles but Iâm no expert, 200ml on a track day whatâs that half pint? I donât know if these engines use that amount or more on track, maybe others can answer that??
I think it is to be expected that on a trackday, you will use oil as you are caning the engine. Trackdays do age an engine. Plus, doesnât the MZR engine, is RWD configuration, suffer from oil surge. Roddison is quoted as saying half a liter per 1000 miles is within spec:
https://www.evo.co.uk/mazda/mx-5/15033/mazda-mx-5-mk3-buying-checkpoints
Always read the oil when engine cold if possible. Take a file to the rear of the dipstick and smooth it down . Then make some marks across it. Is it possible the PCV valve has failed ?
If you have a dipstick with a flat area rather than a dished area, it sounds like the previous owner has already upgraded the dipstick to a more easily read variety.
In my opinion the car would ideally burn less than half a litre of oil per 1000 miles of standard road use.
Track use is a lot more stressful or you are not doing it right so I would expect the oil consumption to massively increase.
As others have said this car needs to have oil kept at the top of the range - lots of engines, particularly the 1.8 where letting the oil drop on the stick has led to disaster.
That alone does indicate that the MK3 burns oil. Â
Evening gentlemenÂ
first of all letâs think WHY the oil needs to be on the âmaxâ mark
Mazda as we all know built a âlight weightâ sports car, and for this reason they didnât want us carrying half a litre of oil we didnât needâŚso basically the n/c engine needs to be kept on the full mark. Think of it as the full mark is the LOW mark and you will NOT suffer oil surge.
today Iâve been out with my mk3 & mk4 on a track day pushing very hard on slicks with no issue whatsoever and neither car needed any oil all day. That said a small amount used on trackdays is acceptable.
paul
There is a revised easier to read genuine Mazda dipstick. Hereâs the link to MX5Parts but currently none in stock.
https://www.mx5parts.co.uk/dipstick-mazda-mk3-35-p-2337.html
Just make sure it is up to the max. The engines donât like being anywhere near the minimum.
Looking at the max mark being the equivalent of low, is it acceptable to add any more over the max mark?
Yes you can but not by much⌠we often run our race cars slightly over full
Half a liter of oil is less than a kg in weight (canât be bothered to look up the density, but its higher than water). NC 2.0 capacity is 4.7l sump plus filter. Mazda3 2.0 MZR is also 4.7l filter plus sump. The Focus 2 2.0 is also 4.7l. So, in the MX5 MZR, your suggestion is that the MX5 needed a 5.2l sump.
What you describe is a work around. Of course there are off the shelf wet sump solutions, but these are never discussed.
My 2008 2 litre has now done 51,000 miles.
When I got the car at 11,500 miles, the oil level was half way between the marks on the dipstick. Since then apart from say one 500 mile trip where the revs were between 4,000 and 5,000 or so some 4 years ago, it does not appear to "use oilâ.
On that one fast run, it used I think, just below 0.5 litres of oil and one of the other cars with a 1.8 engine used a bit more than 0.7 litres. A number of the other Mk3 cars on the run also needed top ups.
Therefore, I can advise that the MK3 cars that I am familiar with can use engine oil when pushed.
First of all, thank you to everyone who responded to my question - your efforts are much appreciated. After reading it all, my thoughts are:
Also, can anyone clarify whether itâs best to check the oil level when hot or cold ? The manual states hot but Paul suggests cold.
Surely the more important consideration is to check it when the engine has been idle for a while (âa whileâ being at least 15-20 minutes), so ensuring that all oil in circulation has a chance to settle back into the sump? When we fill the engine with fresh oil during a service, we check initial level when itâs cold, and before the engineâs been run - makes sense to perform subsequent checks under the same condition. Also ensuring car is reasonably flat and level.
Â
It does not make any real difference whether the oil is checked when engine hot or cold. It is important to wait some time after running the engine for the oil to settle back into the sump and to measure whilst car parked on a level surface.
It is much easier to guarantee the stick reading is correct if you leave engine for at least 15 minutes after running. Withdraw dipstick, clean off and re-instert for reading. If any doubt do again or wait a little longer before doing again.