Mx5 getting hot

redchicken · Postby **redchicken** » Mon Oct 30, 2017 4:56 pm

Hi guys, so just had a new all alloy radiator installed recently on my NB mx5 and went for a drive today, so I was driving up hill around some twisties roof down air con on temperature around 34 degrees I was giving the car heaps. I noticed the temperature guage going up and up, to nielly hitting the hot zone, only falling when I turned the air con off and backed off.The temperature even when up on the way home during a high way run doing 120 in 4 gear. Peoples thoughts?

Magpie · Postby **Magpie** » Mon Oct 30, 2017 4:59 pm

Undertray installed?

davekmoore · Postby **davekmoore** » Mon Oct 30, 2017 5:04 pm

Properly burped?

Do be careful, because the hot zone means "I've already overheated".

Mr Morlock · Postby **Mr Morlock** » Mon Oct 30, 2017 5:17 pm

The radiator- quality- warranty etc. You got it fitted - go back to the mechanic and get them to check it and see where that goes. . Beware if it does boil it can do a lot of damage.

manga_blue · Postby **manga_blue** » Mon Oct 30, 2017 5:26 pm

It takes a fair bit of deliberate effort to get all of the air bubbles out of the cooling system after a radiator is installed and before the car can be dríven. On my car that's usally an hour's work of topping it up, idling it until the thermstat opens again, squeezing the hoses to force the air out, etc. Even after doing that you need to check the coolant level in the radiator, not the overflow tank, during the first few runs to make sure it's not dropping as more air is forced out.

It sounds like your mechanic has neglected to do that, or even to tell you about what you need to do. Take it back ASAP. Overheating quickly causes major engine damage in MX5s.

hks_kansei · Postby **hks_kansei** » Mon Oct 30, 2017 5:37 pm

Check coolant level, if low top it up.

Probably just needs a bleed, which is as easy as idling with the rad cap off and topping it up as it burps out bubbles.

Also check you haven't got a leak somewhere.

GCMX5 · Postby **GCMX5** » Mon Oct 30, 2017 6:16 pm

Magpie wrote:Undertray installed?

I'm with you Magpie.
And Kudos to you for giving this direction to me when we were all at your place.

Mine was doing exactly the same (getting hot under heavy work) but with the correct air direction through the rad, temp is all controlled again.

Magpie · Postby **Magpie** » Mon Oct 30, 2017 6:53 pm

davekmoore wrote:Properly burped?

This is a great tool to fill and 'burp' the radiator. Each year this has been taken to WTAC it has been borrowed by numerous teams...

redchicken · Postby **redchicken** » Mon Oct 30, 2017 6:54 pm

Thanks for the replies guys, forgive my ignorance magpie but what do you mean by undertray installed?

Mr Morlock · Postby **Mr Morlock** » Mon Oct 30, 2017 7:51 pm

Yes - again take it back to the mechanic for a re check.

manga_blue · Postby **manga_blue** » Mon Oct 30, 2017 7:57 pm

Magpie wrote:
davekmoore wrote:Properly burped?

This is a great tool to fill and 'burp' the radiator. Each year this has been taken to WTAC it has been borrowed by numerous teams...

That's way too flash for me. I just cut the bottom off a drink bottle and gaff tape it to the radiator cap hole upside down.

Magpie · Postby **Magpie** » Mon Oct 30, 2017 8:12 pm

https://www.flyinmiata.com/na-nb-plastic-undertray.html

Magpie · Postby **Magpie** » Mon Oct 30, 2017 8:15 pm

Mr Morlock wrote:Yes - again take it back to the mechanic for a re check.

The OP has not said who installed it, it could have been DIY.

redchicken · Postby **redchicken** » Mon Oct 30, 2017 8:54 pm

Hi guys
Yes it was installed by a mechanic

hks_kansei · Postby **hks_kansei** » Mon Oct 30, 2017 9:05 pm

Oh, if a mechanic did the work take it back.

You have a legal right to repair if their work has caused this.
Also, if you give them a chance to rectify the issue it makes it easier for you later should their fix not work and you need to take it further.

But yeah, let it be their problem.