Newly Bought 1989 MX-5

Technical Area Routine Servicing
1
  1. My model of MX-5 is: 1989 1.6L
  2. I’m based near: Luton
  3. I’m looking for technical help or recommendations on: what all should I do first

So I bought the car from fb marketplace on 30/05/2026 from Norwich and drove it all the way to Luton.

So now I’m home I want to take care of all that needs to be done as this car doesn’t have a lot of history in in paperwork

Only what the seller told me

Ie; battery was changed on the 14/04/2026

Timing belt was done two year ago (no receipt hence I don’t have a proof other than her words)

Last service was done on 02/06/2025 at 189518km. Things done:

  • engine oil

  • oil filter

  • air filter

  • fuel filter

  • pollen filter

  • spark plug

  • rear brake caliper

  • rear discs pads

For this I do have the receipt and that’s the only history I have, and when I checked I did see the power steering belt has been replaced recently as it looks new.

Ride back to Luton:

When driving it there was a squealing sound coming from the engine bay I wasn’t sure what that was at first but I seems like to be the alternator belt. It seems to comes and goes after a certain rpm.

Oil is pretty black and previous owner was using 5w40.

Coolant pipes are brittle and radiator has seen better days

Handbrake needed to be adjusted

Plan forward is as follows:

Engine

  • Engine flush using Amsoil engine flush,
  • Using 10w40 semi synthetic oil
  • Motul 4100 SYN-nergy 10w-40 Engine Oil 5L
  • K&N Performance Oil Filter
  • Gates V alternator belt

Cooling

  • New radiator from Bofi
  • Silicone hoses set
  • High flow fans if needed

Gearbox

  • Gearbox flush Amsoil
  • Amsoil 75w90 GL4 oil change

Differential

  • Idk if I can flush is with the same from Amsoil
  • Amsoil 75w90 GL5

Then address the sill rust on the side that’s not been done( I would give this to a professional)

Rest I plan to do it myself

Let me know if I need to change anything or add anything more to the To - Do List I would really appreciate that.

I might consider adding new iridium spark plugs and sparks leads along the way

Thanks you all for their time and going through my list. All and any insights are welcome, again thanks a lot

2

I do about 20k a year in my newer '02 NBFL and always use OEM parts, one exception is the plug leads the originals looked terribly spindly so I use beefier Magnecor leads with original spec NGK plugs.

You mention the timing belt with no reciept I’d check the crank pulley bolts are properly secure for peace of mind if loose they might be causing the squeal, though damp mornings can also cause the same.

Many owners will recommend a water pump swap when the timing belt is done. It would also be worth checking the state of the copper/brass water pump inlet pipe which is known to corrode and eventually leak.

Wishing you many smiles per mile :smiling_face_with_sunglasses: :+1:

3

I wouldn’t personally use an engine flush but I do run some clean oil through an old engine before filling up with new. I would add STP oil treatment to the new oil just for cold mornings as 10/40 is a little sluggish.

4

I would skip the engine flushing additive and maybe use a cheaper 10/40 just to give it a clean out.

5

i was planning to do msd leads but the leads in the car seems not too old, so i was thinking to do the urgent maintainaces first then will focus on the rest
i will definitley look at timing belt and check the water pump for a peace of mind and replace it if it hasnt been done along with the radiator.
thanks a lot

6

For the gear box, get hold of some upper and lower boots, and bushing. Charces are both boots are shredded, and the bushing might be cracked. You’ll under up with a shift that feels brand new

Gear Lever Shift Boot Package, IL Motorsport, MX5 Mk1/2/2.5 – MX5 Parts .._gaNTAwMTMxNzQwLjE3Nzc3NTQ5NTE._ga_9YTNRXK1MQczE3Nzc3NTQ5NTAkbzEkZzAkdDE3Nzc3NTQ5NTAkajYwJGwwJGgxMjk1NTI0MTUy

Genuine Mazda MX5 Mk1 Mk2 Gear Lever Nylon Cup - MX5 Parts.._gaMzU0MDY5ODIxLjE3Nzc3NTQ5ODk._ga_9YTNRXK1MQczE3Nzc3NTQ5ODgkbzEkZzAkdDE3Nzc3NTQ5ODgkajYwJGwwJGg5OTYwMzY5NTk.

Check the slave cylinder; pattern items are fine.

If changing the hoses I recommend OE Mazda

Iridium plugs; waste of money, I stick with NGKs

When removing the plugs, if there is oil on the threads, the camcover gasket is shot. Replace with OE Mazda, not pattern. Replace CAS O-ring at the same time

If the handbrake seems weak, possibly the rear calipers will need replacing.

7

Thanks alot for that input
i would definitely get the pacakge for my shifter also i do plan to get the ISR Performance Short Shifter Mazda MX-5 NA (Mk1) NB (Mk2) 5 Speed so should i other something along with it?
why not the silicone hoses for cooling?
i was planning to use this one Stoney Racing Silicone Coolant Hoses Mazda MX-5 NA (Mk1) 1.6 from Bofi since i already plan to upgrade my radiator.

oi would chesck the sparks plugs and makes sure
once again thanks a lot

8

Short shifter kits are mostly terrible. You already have a short shift.

Mazda hoses are proven. 270k kms and counting.

9

thank you for that i didnt know that :sweat_smile:

10

I looked at the same silicone hose kit and it does look good value for money, Bofi are good too so dont think they would sell rubbish.

11

That’s my same thought

12

Sorry again

What are the takes on using beatrush busing instead of the nylon one

13

It’s £25 versus £5, and I’ll guarantee you’ll notice absolutely no difference compared to the £5 OE part. Obviously the reviews are good when compared to a 30 year old part.

You’re better off baselining the car with OE parts before blundering down the modifications.

14

A pollen filter in an NA? Doubt it.

If you can be bothered change the trans and rear diff oil. Speak to bofi they’ll point you in the right direction oil wise.

I’ve stuck mobil 0-W40 in my 1997 NA this year and It seems a lot quieter on startup.

15

My thought too. Though you can get one from jass as an add on.

16

Maybe JDM thing?

17

I wasn’t sure either with receipt

But I don’t think think this car has one