Advice on "While I'm there" for timing belt and cooling

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: Mk1 97
  2. I’m based near: Edinburgh
  3. I’m looking for technical help or recommendations on: What other jobs to do/

Hi everyone,

My car has just hit 100k km and its time for a timing belt and cooling system refresh. I have collated a list and wanted to know if I was missing anything essential or just any ‘while I’m there’ things to do. Do you guys think its worth doing a head gasket whilst I’m doing the timing belt job?

Timing Belt

timing
timing1159×574 32.6 KB

Waterpump included within timing belt kit

Cooling System

cooling
cooling1157×183 14.9 KB

Is there anything else that I can do while I have everything apart. I have been thinking about a new coolant expansion tank. Let me know what you guys think.

Cheers
British Racing Bean

2

I wouldn’t bother with the coolant reroute or the fancy radiator, the money you save on those two items alone would pay for everything else.

3

You seem to have 2 crankshaft seals and only 1 camshaft seal. It should be the other way round.

4

Hi. My plan was to turbo the car in the next few years and wanted to create a stable platform for it. I haven’t bought the coolant reroute yet but I understand that it fixes a fundamental issue for cylinder 4 overheating. I have purchased the radiator however because it’s shiny.

5

Good spot. I must have got it mixed up when making the list. I’ll get this swapped out. Any advice on whether doing a head gasket is worth it before the timing belt job. It will make the coolant reroute easier too. I’m not sure if head gaskets are a time replacement item or wear replacement. Engine is on just over 100k.

6

I was advised to use a genuine Mazda CAS O ring

7

You could consider a cometic head gasket as the oem ones can fail with turbocharging. Here’s a useful link How to keep your Turbo MX-5 / Miata Alive | Mazda MX-5 Performance Parts | BOFI Racing

8

Consider converting to an Evans Waterless coolant

9

I looked for one but didn’t see a genuine one for sale online on bofi or mx5 parts.

10

They look expensive but maybe worth it in the long run. Question is whether I should attempt this job during the timing belt change. Probably adds 2 days to the repairs.

11

Only when turbo’d or in general after the cooling systems change?

12

The main benefit of a waterless coolant is lack of pressurization, useful on an elderly cooling system. It saved my motor at least twice (first a failed cooling fan, then a thermostat stuck closed)