Help/opinions On Overheating Problem

[Blood]

Ok,

When driving after 30mins or so. Either highway or backstreets (probly more highway, strangely)

The car will heat up, according to the temp gauge.

I have an alloy radiator, with a thermo on the back. No stock clutch fan, just thermo and it runs 100% of the time.

The other crappy fan on the front of the a/c cooler is also fitted.

When i drive on the highway 80km/h or less it sits about half way..

100km/h+ it will rise.

100 it slowly rises, 110km/h it rises much faster ....

Any ideas ?..

I was thinking just the temp. switch but really not sure. I come to this thought because while on the highway and it is 3/4+ on the gauge, i put car in neutral and switch off. The turn it back on straight away (after engine stops) and the gauge is half way again.

??

When at 3/4 temp, and i stop the car the overflow bottle does NOT seem to be boiling or getting water pumped into it.

Had the same problem with clutch fan, which is why i went to the thermo. But still has a bloody overheat problem

I have flushed the radiator twice. fitted a thermo and it runs all the time when ignition is on. just at the higher revs it seems to heat up quicker (3200rpm or higher)

Any thoughts ?.. (was thinking of taken it to red devil radiators or somewhere.. as in take entire car there, but really tight on funds atm)

[mad082]

i'd start by either buying an aftermarket water temp gauge, or getting a consult cable. with the consult cable you can see what the temp is that the ecu seeing. it uses a different sensor to the dash. either of those options will allow you to see whether the problem is actually a temp issue or a sensor/gauge issue.

if it does turn out to be a heating issue then it could be caused by the thermostat ot possibly the water pump.

also i hope you aren't turning the car off while cruising along at 100kmh.

[MrStabby]

mad's advice is good. But if it were me i'd just pull the thermostat out, and go for a drive to see if that's it. If that fixes it get a definitely fit a new one as it helps your motor get up to temperature quicker, and that's important in the long term.

[Blood]

Thanks for fast reply.. Pulled out thermo stat.

Seems good, although i didnt take car for a drive with no thermostat installed.

I tested it with boiled water from kettle and it opend up ect..

Re-installed it and went for a run...

Im pretty sure its a blocked up radiator as its a 2nd hand one... was fitted just over a week ago (and hte problems were there from then in a way)

Whats it cost for a professinal flush/clean ?

Im located southside of Brisbane so any advice on where to take it to ? (i know its cheaper if i pull it out of the car)

[Curmi]

buy new asi radiator $200........new thermostat worth the upgrade from shitty 20 year old one, new water temp gauge stock one fails baddd. then all should be sweet.

[blind_elk]

Firstly, having the thermo running 100% of the time is basically defeating the purpose for having a thermo. It only needs to run when the temp gets too high - and by too high, I mean 10 or more over thermostated temp.

The general problem I have found is getting air to flow through the radiator. It is too easy for air to simply travel down the front of the radiator and out underneath the car.

Is the fan turning in the correct direction, ie pulling air through the radiator? And it probably wouldn't hurt to get the radiator cleaned and serviced, particularly as it's second hand.

[DRFT_ceffy]

are you able to chuck the rad shroud and clutch fan back on? with that alloy rad. If so i would give this a shot, seen this happen alot and its amazing how much of a difference the shroud and clutch fan actually do make.

[Rekin]

Thermo fan is pointless without a proper shroud.

Search for AU Thermo fans in google and/or SAU.

Best bang for buck for a good thermo fan/shroud setup if you have the space.

[Blood]

Ok, played more today

Found that the alloy radio had a fair bit of crap still in it

I have removed that and put a stock one back in. With thermo attached.

Now it doesnt get above half.... Yet to test on track.

Im thinking of going back to clutchfan and shroud (i need a new shroud).

I have 2 thermo fans setup.. i done the same to my ole RX7 and that thing never ever got hot. (one on front pushing air, one on the rear sucking air)

I know it takes that little bit longer to warm up.

Anyhow, after using acid to flushout/soak the radiator(s) i found that even more brown crap came out. After a reverse-flush with garden hose that is.

Afterwards i used acid, and caustic soda (lean mixture) and then Battery acid. (advised these are the best to use by a helpful fella at Radiator shop @ Archerfield).

The acid removed quite alot of more crap. that the standard flushing wouldnt use.

[royb31]

thermo's are fine if set up correctly if you dont want to go back to the clutch fan on the engine. for controlling the fans use a SPAL fan-pwm fan controller to control the fans, great piece of kit costs between $250-275 depending on where you get it from, you can get them from air con wholesalers JAYAIR or any good radiator shops. Not to hard to fit good instructions. It uses pulse width modulation to control one of your fans which slowly increases fan speed from 50% to 100% from a predetermined set point that you program and if running 2 fans will start the 2nd when the high point is reached.If you have a big FMIC this can also affect the amount of airflow to the rad look at fitting a top panel where your bonnet catch is from the front bar to rad support and the same on the bottom to force air through rad air will take path of least resistance -this is a common mistake on gtr's where the front splitter is removed.