Do Mx-5's hate hills?

Postby **NitroDann** » Wed Oct 09, 2013 1:43 pm

angusis2fast4u wrote:
NMX516 wrote:Agree that there is nothing wrong with a properly functioning standard cooling system, so there is something that needs to be sorted with yours.

The only time I've had overheating troubles was on a track day. I removed the bling grill and that solved the problem!

Also ensure that the radiator has the foam insulation around it to prevent air escaping around the radiator and not getting through it. Also check that an under tray is fitted, for the same reason. Your 52mm rad is overkill and could easily be the cause of the problem - too thick for the air to pass through, so the above issues become even more important than they otherwise might be... The air will take the path of least resistance.

I had the same issue with the standard radiator which is why i upgraded but it has not changed much at all i.e. It takes longer to warm up so i know its doung better but it seems to 'get hot' (3/4 hot on the gauge) in the same time but seems to just stay there while the standard radiator would actually get hot and over heat after a period of tine

Sounds like your thermostat it slightly stuck open.

Dann

PaulF · Postby **PaulF** » Wed Oct 09, 2013 3:19 pm

angusis2fast4u wrote:It doesnt happen going up my nebo, its only the steeper sections which are coming back up mt. Glorious and going up mt nebo from samford when the engine is mainly revving high in second with not enough power to just hit 3rd

angusis2fast4u wrote:not enough power to just hit 3rd

angusis2fast4u wrote:not enough power

There's your problem.

JBT · Postby **JBT** » Wed Oct 09, 2013 10:07 pm

You should be able to drive up, down and around those hills in 2nd gear if you want and the car should not overheat.

Guran · Postby **Guran** » Wed Oct 09, 2013 10:36 pm

The standard cooling system on my car lives at 5000-7000rpm over the last five years of regular track days and supersprints. I've never had the temp go past medium ... until a few weeks ago at Eastern Creek. After 2 laps the gauge was nudging the high mark. Back off for half a lap and it returned to medium temp. Idle in the pits and it sat on medium. The issue was solved with a new thermostat.

Simple test: remove the thermostat (5 minute job) and drive for half an hour or so. It should run cold on the gauge most of the time, and increase towards medium if you drive up a steep hill. If you still see overheating then your problem is not the thermostat. But I suspect it will be. Even brand new thermostats can stick.

And while the thermostat is out, do the boiling water test I mentioned earlier. It only takes 10 minutes.

angusis2fast4u · Postby **angusis2fast4u** » Thu Oct 10, 2013 12:49 am

PaulF wrote:
angusis2fast4u wrote:It doesnt happen going up my nebo, its only the steeper sections which are coming back up mt. Glorious and going up mt nebo from samford when the engine is mainly revving high in second with not enough power to just hit 3rd

angusis2fast4u wrote:not enough power to just hit 3rd

angusis2fast4u wrote:not enough power

There's your problem.

+1 hahaha

OurCognitiveSurplus · Postby **OurCognitiveSurplus** » Thu Oct 10, 2013 10:48 am

I've had some unusual cooling problems with my MX5 over the years. The heart of the issue was that the actual blades of the pump were slightly the worse for wear (120,000km old pump - previous owner didn't change when the belt was done - what a knob). Basically this caused poor flow of coolant.

New pump = all cooling problems solved.

angusis2fast4u · Postby **angusis2fast4u** » Sat Oct 12, 2013 10:16 pm

OurCognitiveSurplus wrote:I've had some unusual cooling problems with my MX5 over the years. The heart of the issue was that the actual blades of the pump were slightly the worse for wear (120,000km old pump - previous owner didn't change when the belt was done - what a knob). Basically this caused poor flow of coolant.

New pump = all cooling problems solved.

thanks man ill crack mine open soonish and see what condition it's in, im guessing it could be a mixture of things as well, shouldn't be hard to fix (hopefully)

OurCognitiveSurplus · Postby **OurCognitiveSurplus** » Mon Oct 14, 2013 9:35 am

Maybe someone with more experiance could varify this - but if you open the top tank on the rad (cool car obviously) and then start the car, you should be able to see the water flowing through the top-half of the rad. Not like white-water rush, but like a flowing creek. If the water looks stagnent (i.e. quite low flow), a weak pump is an issue.