A little overheating

Staaahp · Postby **Staaahp** » Tue Oct 25, 2016 10:35 pm

Hey all,

So I own a turbo NB running a T28, PWC radiator and FMIC.

I decided to take the mx5 to uni today up in Randwick (car rarely sees crappy traffic) and on the way home I realised something a bit odd. I realised that my oil temperature was reading ~115-120C opposed to the usual 100C when fully warm. Thermostat reading on the cluster was also a quarter past 12.

Given I was crawling in the congested M5 tunnel at no more than 15kmh with the AC on during a quite warm day I was still pretty surprised.

Exiting the tunnel, temperature gradually returned to normal and when I got home I checked that both the fans were working as intended and fluids were intact.

Kinda scared me a little, I'm sure this isnt normal?

A.Chen89 · Postby **A.Chen89** » Tue Oct 25, 2016 10:41 pm

Not sure where you have your cooler but having the AC isn't helping the car when it's stationary/low speed.
There isn't enough air flow to remove the heat from the radiator/oil cooler/AC condenser with just your fans. Try some beefier fans or ducting or just turn off the AC

Staaahp · Postby **Staaahp** » Tue Oct 25, 2016 10:50 pm

A.Chen89 wrote:or just turn off the AC

Yeah it was pretty much the first thing I did when I noticed. I gathered airflow may have been restrictive crawling in a tunnel and all but was just a bit surprised given the car wasn't in boost or being dríven hard.

manga_blue · Postby **manga_blue** » Wed Oct 26, 2016 6:20 am

Fans don't pull as much air through the radiator as driving at normal speeds does but usually they do work well enough in stop/start traffic. It's worth checking that there are no bugs or debris impeding that airflow enough to make the fans ineffective. Otherwise is it possible that your ignition is too retarded or your mixture too lean under those conditions?

Magpie · Postby **Magpie** » Wed Oct 26, 2016 6:34 am

Do you have the OEM undertray installed? Also have added an vents to the bonnet or raised it? Notwithstanding that oil temp would not be too concerning as oil will handle higher sustained temps than the coolant.

A quick solution, albeit an uncomfortable one is to turn your heater on full as this helps draw off some of the heat.

sailaholic · Postby **sailaholic** » Wed Oct 26, 2016 6:49 am

If you are running factory fans still I'm not surprised. They are ok for OEM radiators but you've added a heap of core thickness but upping the radiator and then putting a inter cooler in front of that.

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manga_blue · Postby **manga_blue** » Wed Oct 26, 2016 7:28 am

sailaholic wrote:If you are running factory fans still I'm not surprised. They are ok for OEM radiators but you've added a heap of core thickness but upping the radiator and then putting a inter cooler in front of that.

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True
I'd missed that. Thicker radiators can in fact impede cooling at lower speeds.

speed · Postby **speed** » Wed Oct 26, 2016 7:47 am

Mine will also have a thicker radiator and IC in front of it.

What fans do people recommend to improve airflow?

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smy0003 · Postby **smy0003** » Wed Oct 26, 2016 8:01 am

I have no issues with a single eBay slim fan. I've never seen above 90deg water temps.
That's with a big mother eBay rad and coolant reroute.

Two eBay slim fans would probably be ideal.

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Staaahp · Postby **Staaahp** » Wed Oct 26, 2016 10:05 am

I'm still running the OEM shroud and undertray. I suppose giving the radiator and cooler a light pressure clean on the weekend to rid of flying bugs and what not wouldn't hurt too.

MrsB · Postby **MrsB** » Wed Oct 26, 2016 9:37 pm

best answer is to run a cross flow radiator and either the evans coolant or redline water wetter or equivalent. Also a couple of oil coolers are not a bad idea

Apu · Postby **Apu** » Wed Oct 26, 2016 9:46 pm

I drive down Victoria Road to work and the traffic there can get quite bad, and I seeing 110degC oil temp was not unusual. I have an OEM replacement radiator for the auto model which has a slightly thicker core but not as thick as an alloy radiator.

I recently had Mania install a Derale Typhoon fan and so far, have not seen oil temps pass 100degC. You might want to try that.

speed · Postby **speed** » Thu Oct 27, 2016 8:17 am

smy0003 wrote:I have no issues with a single eBay slim fan. I've never seen above 90deg water temps.
That's with a big mother eBay rad and coolant reroute.

Two eBay slim fans would probably be ideal.

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Thank you. Will have to get one (or two).

Staaahp wrote:I'm still running the OEM shroud and undertray. I suppose giving the radiator and cooler a light pressure clean on the weekend to rid of flying bugs and what not wouldn't hurt too.

I'm looking forward to seeing your beastie at the dodgy day

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