skc

My car is NA and at the at the last track day my radiator light was coming on if I held the revs too high. This is the second time this has happened. The first was due to the oil being low. This time the only thing different was that I was running the car without the engine cover.

I have taken off the rubber seal near the windscreen to vent the excess temp and the outside temp was in the low 20's.

Could the removal of the engine cover be the cause of the overheating? Unfortunately I had left the cover at home so I could not run subsequent laps with the cover on to see if this was the cause of the problem.

skc

Revolver

I've read that the engine cover does assist air flow for cooling purposes but I don't know how critical it is.

I've just removed mine because I've installed a 4 point MazdaSpeed strut brace and it no longer fits. I suppose I'll find out at the Nats whether cooling has been detrimentally affected...

takahashi

I am too lazy to search the thread...

if it only happen on high rev but not necessary because it is hot! It could just be the sensor.

I have excessively run my car in the low 30 degree. The water temp only reach as high as 114 degree. Normally it is under 110 degree. In Winter like now, it is barely over 100 degree even at Sandown.

No lights even in this situation.

skc

I am getting Mazfix to put in a larger capacity radiator and a second oil cooler on Wednesday.

This should hopefully resolve my radiator light issue and keep things cooler under the hood. Outside temps are going up. Its in the 30's today.

skc

matt13b

I have had my engine cover off for years and have caned my car and never had a heat issue(touch wood)..So I don't think the cover does anything but stop owners from fiddling with their engines.

swoope

iTrader: (5)

with some miles on the car. some issues with the sensor that is the coolant level light..

i am on 97k miles.. i get it every now and then. just make sure the coolant level if full when cold..

btw, i am running the bhr rad, it is cool, very cool..

and if you drain the coolant holder, and put a spray hose in the inlet.. and spray hard.. well it tends to clean things up a bit..

beers

skc

Mazfix will be fitting a PWR radiator.

http://www.mazfix.com.au/perfproducts/rx8_upgrades.html

skc

swoope

iTrader: (5)

just a yank posting here.. but only two improvements in radiator flow..

bhr and mazdamart.. and mazmart has a zesty smart h2o pump. i would take time to look at it before you waste money on a rad that is worse than stock.. and stock is pretty damn good..

the second oil cooler is paramount.

but what do i know..

beers

takahashi

Interesting Mazfix charges $950 for the radiator while the stock price is $780. That is include install?

I doubt the solution is a bigger radiator, having said that I will love one down the track. Not Koyo lol. Sorry Drew.

skc

Thanks for your comments Swoope. Your climate will be very similar to what we experience here in Brisbane...hot and humid summers.

Archie recommended the second oil cooler and i will be definitely fitting this.

I take your point on the water pump...I think there was a group buy which I missed out on recently.

However, I thought the larger radiator would be better than stock. I also thought it may also solve my radiator light issue as it may be as a result of a faulty sensor.

I always check my coolant levels and they are at the correct level so if it is a faulty sensor then I am up for $$$ anyway.

Why do you think that the PWR radiator is worse that stock?

I appreciate your comments as I certainly do not want to spend money on mods that will have a detrimental effect.

skc

Brettus

iTrader: (2)

The rad light is the level warning light ! Are you really going to fit a new rad. because your level light came on ? Do you even know what your water temps were ?

skc

Yes Taka, that is the installed price and for that you get a larger capacity alloy radiator.

skc

Jambos

Salesh

I had the same problem, took it to mazda and low and behold it is a common problem with the 8, they knew straight away the symptoms, fix includes new coolant tank and sensor, all fixed under warranty and all good as new.
See you and the others on Saturday.

Laurence

swoope

iTrader: (5)

as brettus said..

if you dont know your temps you are behind the curve..

as to the pwr radiator. until it is proven as in the koyo in the states,, i think you are likely pissing away money..

the second oil cooler.. well brettus is in charge of that.. i think..

it is complicated, but give options..

my best idea is dont **** away money on a rad that does not offer more... check the fans first.

and i have other ideas. but what do i know..

pm me if you need some ideas.

beers

swoope

iTrader: (5)

and yes the coolant overflow tank is a problem here..

beers

skc

Sorry, no gauges so no idea on operating temps. The coolant level was normal when I checked before the track event.

The light only came on occasionally on the back straight just after a slower section where the revs where held high on a prolonged basis. This has me worried as you hear that one of the causes of engine failure is over heating...so to me a red flashing light means danger. However, if is only a faulty sensor than to may not be all bad.

skc

Brettus

iTrader: (2)

When you are at high rpm - the pump can suck the water out of the tank and pressurise the system so it is possible that the tank level goes down below the sensor level switch for a while till the level equalises .

skc

Laurence,

Unfortunately, my warranty ran out a while ago so I will have to pay extra for the sensor. I will need something done about this before the weekend.

skc

swoope

iTrader: (5)

and yes again. it will dump just a bit of water.. enough to make you wonder, or enough to mess up the power steering connector.

beers

skc

I have seen a larger capacity reservoir for sale on the forum...may be that will resolve the issue.

skc

Brettus

iTrader: (2)

maybe - the stock one is a tight fit in there so I don't know how that goes .....

takahashi

skc

Certainly I heard when they first come out they have to bend the bracket to make them fit.

For your info, I recent had to replace the bracket for other reason the replacement part from Mazda is $1-200 (hopefully I remember it wrong).

The sensor is reservoir area and if you know the water temp and unplug the sensor which is the grey one next to reservoir. That will solve the problem

Better to know what the water temp is to see the effect. You are unfortunately shooting it blind skc!

rotarenvy

now the summer is heating up I have been getting the red radiator light flashing up on my dash and rapidly rising oil and coolant temps. here are some of my observations:

cruising my engine temp is about 95deg which seems ok for a modern vehicle. I base this on my gauges which have the oil on the out-let of the motor and it reads 98deg and my water temp on the inlet which reads 89deg.

if I started to overtake or use revs higher than 3500rpm temperatures would quickly climb and I would get the red radiator light. it would rapidly create oil outlet temps over 100deg and water temps followed and would climb to 110deg. in a traffic jam I had even higher temps.

a lot of my problem is probably due to a big intercooler blocking 98% of the air to the motor however I did find that coolant mixtures made a big effect.

I was running a 60g per liter ethylene glycol mix and it just isn't enough! using a 1000g/L ethylene glycol mixture significantly helped the red radiator indicator coming on. I put this down to reduced boiling and expansion. I over filled the radiator above the max level so I might not have seen the radiator light if I had the correct level. I have forgotten how much ethylene glycol is in the mazda concentrate but I think they recommended 3 bottles for the 10L coolant system. I wonder how this compares?

I would recommend further oil coolers and the larger greddy sump before a new radiator since water temp follows oil temps. cooler oil going back into the sump. the larger oil volume will help slow the rapid temperature rises when using high revs and the radiator should be better able to cope with the temps.

also I have noticed the A/C radiator fan needs the interior fan "on" to switch on. this fan has a large impact on coolant temps. the fans turn off at high road speeds but it defiantly seems to have an effect round town.