mx5cartalk.com

45+ degrees here yesterday. Temp gauge on exactly its usual dead central position and coolant level in the expansion tank on the max level line. Gurgling noises from the cooling system when parked though.

Is this just a normal reaction to the extreme heat?

Or is the temp gauge a joke gauge like the oil pressure one and merely shows the middle position all the time and fails to let me know that there may actually be a problem?

It's OK. The temp gauge has a "normal range" dead spot. It will show hot when the coolant gets hot enough.

Apparently it shows hot when you're already well into trouble.

Fair amount of pinging on any decent amount of throttle though

Are you using 98 octane fuel?
What modds / boost are you running?

I'm with Minx, if you're running 91, it would be borderline in that sort of heat & cause pre-ignition, pretty much how I found out our Tribute preferred 95/98, a stinking hot day in Tassie (yes, they DO get hot weather down there) & the tribby was pinging it's nuts off under any form of acceleration.

Time for coolant re-rout ??? Get rid of that hot spot........ its all i've been researching this week

most factory gauges only move when water temp is aboue 100c

in my old 180 it would only creep up when my gauge was reading 105

decent gauges are essential for any modified car

Given this is posted in the FI section I'll assume you have boost...
That's going to = lots of extra heat, and a hot day leaves not much to cool the engine down. Try either not getting stuck into it in extreme temps, or a retune with a bit more fuel/less timing in the temp compensation maps.

What mods have been done to the SE?

Okibi wrote:What mods have been done to the SE?

The car was Blackster's. Credit to him for, amongst other bits:

Mazdaspeed AEM air intake
Cooling Pro intercooler
SP Motorsports exhaust system
Denso 440cc injectors
GFB recirculation valve
BEGi TB inlet
Mazdspeed oil cap
Haltech interceptor
Haltech boost solenoid
OG 02 Clamp
170.8rwkw @ 14psi AFR 11.5
Standard pistons and rods so rev limit not increased

Always 98 octane by the way. And yes, when it's really hot I take it easy on the motor. And the oil's just been changed. There's a modded IHI plus ceramic coated dump pipe ready to go on so might have the tuner (when I've found someone near Mornington Peninsula who can do it - hint for info please) wind up the AFR a touch when it has to be retuned for that?

Could consider running lower boost on the hotter days to help keep temps down and a bigger radiator isn't too expensive.

Can also look at making sure all air that runs though the front of the car hits the IC/Rad and doesn't get obstructed by the licence plate or flows through the radiator instead of under it.

Okibi wrote:Could consider running lower boost on the hotter days to help keep temps down and a bigger radiator isn't too expensive.

Can also look at making sure all air that runs though the front of the car hits the IC/Rad and doesn't get obstructed by the licence plate or flows through the radiator instead of under it.

Haven't looked into how easy it is to swap between maps but there is a 150rwkw map as well so I'll be finding out. Short term I guess I can vary the boost with my right foot eh?

There's no front licence plate on the car at the moment (stick-on one will hopefully arrive next week).

Bigger rad might also be the go but not sure how much room to spare with the bigger intercooler already there. Prefer more cooling to less right foot though.

Are there upgrades to things like the fan/water pump/themostat/etc as well as or instead of bigger rads?

Anyone tried using a coolant additive that claims to improve cooling?

pull some timing out asap that will solve most off your problems,
this will stop detination & naturally cool the motor down by a few deg, im guessing it has been tuned with a fair bit of timing in it for more power, fyi the factory ecu does use a knock sensor but wont do its job as the interceptor will notice the ecu pulling timing & add more.

ive had the pleasure of overheating my nb motor & the gauge does show hot, but we are lucky enough to have all the good parts in our engines like metal headgaskets from the factory which helps alot with post overheating problems as long as it is attended to quickly & is cooled slowly i.e dont try pouring cold water into your radiator let it cool natually otherwise you run the risk of cracking alloy components like your head....

also i have heard very good things about "redline water wetter" & will be using it when im putting my car back together

on a side note, you have an aftermarket radiator, make sure that there is a seal between the front of the radiator & the radiator support panel, this can be easily done by going to clarks rubber & getting 1" or so firm foam strips & stick them between the two which will stop air escaping through the gaps & making sure it goes through the radiator.

i dont know anyone on your side of town but can recommend a workshop in coburg, if its not too far out your way p.m me.

I hope this helps you somewhat

There's 2 fans on the radiator, one that kicks in when the coolant temperature starts to get too hot and another that only kicks in only when the aircon is running. You can modify the aircon fan to switch on when the other fan does so without the aircon on you get even more cooling when stuck in traffic.

There's a write up on miata.net in the garage section I think.

sprx3 wrote:pull some timing out asap that will solve most off your problems, this will stop detination & naturally cool the motor down by a few deg, im guessing it has been tuned with a fair bit of timing in it for more power, fyi the factory ecu does use a knock sensor but wont do its job as the interceptor will notice the ecu pulling timing & add more.

also i have heard very good things about "redline water wetter" & will be using it when im putting my car back together

on a side note, you have an aftermarket radiator, make sure that there is a seal between the front of the radiator & the radiator support panel, this can be easily done by going to clarks rubber & getting 1" or so firm foam strips & stick them between the two which will stop air escaping through the gaps & making sure it goes through the radiator.

Thanks sprx3. Yes, it helps.

There's already foam all the way round the rad - doesn't seem especially firm though, and looks factory. What makes you think I have an aftermarket rad by the way - or did you just miss off the word "if"?

I guess the larger intercooler in front of the rad isn't helping matters much.