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How to: Change your oil
Please read this guide in its entirety before picking up any spanners. Skipping ahead or rushing could cause you problems further down the line.
This guide applies to all models of Mk1 and Mk2/2.5 MX-5s. The theory is the same for the Mk3 but the placement of filter and sump plug will be different.

When does it need doing?
Oil is the most important fluid in an engine and performs several tasks including:

- Lubrication of moving parts
- Provides a reduced-friction surface
- Transfer of heat away from engine internals
- Protects bearings and prevents metal-to-metal contact

If you run out of coolant you overheat, run out of oil and your engine will be destroyed. Needless to say the oil system shouldn't be neglected.

You should change your oil and filter regularly (at least every 12 months) and check for leaks at least once a month. Preferably get in the habit of checking your oil weekly and chack for any signs of leaks at the same time. By the time your oil warning light comes on it may already be too late so don't neglect this.

What do I need?
19mm socket and wrench
At least 5 litres of oil (5w30 semi synth)
Kitchen paper or old rags
A new filter

Jack up the car following the jacking guide. Ensure the car is high enough to allow plenty of access underneath. If possibly, changing the oil should be done with the car horizontal so a pit or ramps with the rear raised and supported would be ideal. If not, just supporting the front is suitable.

It is also advised to run the engine for approximately 5 minutes prior to removing the sump plug. This allows the oil to warm up and become less viscous (flows better). Be sure to not run it for too long or the oil will be too hot and you risk severe burns to your hand and arm.

How do I do it?
With the car jacked and supported, jump underneath and you'll see a 19mm bolt just behing the splash pan. It's very obvious when you look

Step 3 - Crack off the bolt with your socket then you should be able to do the rest with your fingers. Make sure you've got a container ready to catch the oil (bank on 5L then you won't spill it!)

Be aware that the oil will come out quickly initially and also probably be quite hot so be careful. The trick is removing the sump plug without getting covered in oil and without it ending up in your container full of old oil!

Step 4 - Clean up your sump nut and remove any old washers you may or may not find fitted. Kitchen towel is invaluable when performing an oil change

Step 5 - Now head up to the engine bay, we are going to hunt down the oil filter

Step 6 - Standing on the driver's side look under the metal tubular thing (that's your inlet manifold) and you should be able to make out a cylinder protruding from the block. If it's white you'll find it much easier to see but the genuine Mazda filters are black to make it a bit trickier!

Step 7 - Due to its position and the fact it will contain a small volume of oil, I recommend you stuff a load of towel or rag underneath it to catch inevitable spillages

Step 8 - Stand towards the front of the car, reach in and get a good grip with your left hand, squeeze hard and really crak the filter off. Do it right and do it once then you won't have any bother.
If the previous idiot .. I mean owner has done it up stupidly tight then you're going to need a filter wrench. Due to the obscure location you may need to talk to Mazda about getting one of their special servie tools (SSTs) but a chisel and big mallet can still work wonders!

Once the filter releases you'll be able to easily undo it by hand and lie it down so the face against the block faces upwards as shown in the picture (this keeps all the oil in the filter rather than on your wishbone etc!)

Step 9 - Get some more kitchen towel in there and wipe around the mounting face on the block where the filter sits. Try to keep everything as clean as possible

Step 10 - Get your nice new (Mazda?) filter and remove the packaging that protects the seal and filter

Step 11 - Pour a small amount of fresh oil into the cap of the tub and dip your finger in it. Use this to run a line of fresh oil around the rubber seal for the filter as shown

Step 12 - Once you've gone round the whole seal, put the new filter in place (you'll have to do this pretty much by feel alone).

Make sure you don't tighten it up too much because it will only make your life more difficult next time. Tigthen it until you fee resistance then give it about 1/2 a turn

Step 13 - Your sump should have reduced to a very small drip by now, if it hasn't then go and have a cup of tea (and stop working so quickly!)

Step 14 - Fit a new sump nut washer then replace it in the sump

Step 15 - Tighten the 19mm nut up with a torque wrench if you haven't done this a thousand times before, otherwise you know the drill, no leaks here

Step 16 - Empty the content of the oil filter into your oil catcher then dispose of it

Step 17 - I tend to find the best way of getting rid of oil is to siphon it into a big tub as shown. This will do about 10-15 oil changes before a trip to the local tip gets rid of it

Step 18 - Pop the oil cap off which is found on the right hand rocker cover as shown

Step 19 - Put plenty of tissue around in case you spill oil and don't want to destroy your nice pretty rocker cover then pour in about 3 litres of new oil. Once you have done this, use the dipstick to check the rest

I've heard people have had problems with half the dipstick reading one value and half reading a different one, simple cure is to spin it through 180 degrees before you remove it!

Step 20 - Once you've done all that, fire her up and check you have good oil pressure. Spend a good 30 seconds looking for leaks from the filter or sump nut then take her out for a spin. Always keep your eye on the oil level for a few days and check for any signs of drips.

*Original guide and photos by JSeaman (edited by Monkfish to fit the FAQ template)*
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