My first overheat

[Kezpipa]

89 L series.

Hi, while idling in the traffic on the Hume yesterday I noticed my temp gage was in the red, I've never driven a car with the gage so high before. I don't know how long it had been like that, but we'd been in that traffic for at least half an hour.

10 minutes later the car was finally in a space to pull into a sidestreet and cool down.

The coolant in the overflow bottle was boiling and spitting, this was leaking out onto the ground as well.

I gave it 40 minutes to cool down and then refilled the overflow with tap water (all I had) and drove it home, the gage didn't go over half this time.

My car mate had a theory that sitting in idle traffic caused it to overheat; (weather was pretty warm in Melbourne yesterday) but my workmate thinks it might be some electric problem where the extra fan isn't being told it's needed...

Any thoughts? Plus is there something I should do about it ... is it likely it caused my engine damage with the gage so high ? (it was halfway through the red section of the temp gage, and by the time I parked about 4/5ths of the way through the red). (And that coolant bubbling and hissing out through the cap, youch.)

Any thoughts would be appreciated, still a noob to cars, I know I've been saying that for over a year now!

Kez

[BaronVonChickenPants]

Sounds to me like you're fans didn't come on when they should have.

If you're lucky your engine will still be ok but the odds aren't good.

Jordan.

[fredsub]

Some overheating shouldn't cause much ongoing problems, I've had my engine overheated heaps at various times for various reasons and its still going....provided you don't thrash it at the same time, the engine is going to be just fine :P

[mattims]

yeah mines gone a few overheats that far into the guage on sand work.. but then my headgasket is only held together with chemiweld now. I imagine these two things could be related. I'd check the oil level pretty quick, whenever mine has got that hot its eaten lots of oil too.

[Kezpipa]

Thanks for the comments I will probably get the fans checked the next time I take it in - at the least, this has taught me a valuable lesson about checking the temperature gage more often.

[Phizinza]

I have a problem with my fuse box. Some times the fuse for the radiator fan/radio doesn't make a connection, just have to pull it out and put it back in. Although now my radio is dead, so I can't tell if the fan is working or not. If you are going over 40kph you shouldn't need a fan at all, but idle makes it very warm. I also don't have a belt run fan on my EA81, just an electric.

[ToyRX]

When you pulled over and popped the bonet the thermo fan should have been going, if it was not then there is your problem. If it was going then you will need to delve a bit deeper into the problem. I would recomend a full oil/filter change as oil breaks down very fast at high temperatures and it is likely your oil is stuffed.

[twc]

agree with the oil change .do it now . also look at the oil that comes out in case you something odd.

[smoov]

like metal shavings, funny coloured oil (ie caramel coloured) etc etc.

[mattims]

or a rabbit .. cause that would be odd

[Kezpipa]

lol Mattims... wasn't expecting that!

[FISH_Stalker]

My rig dosnt like ideling in sets of trafic lights, but the faster i go, the cooler it gets. The electrical fan isnt commin on, the sencer is stuffed.

[mattims]

yeah just wire it up to a switch (or ignition power if your lazy).

[fredsub]

don't know about your series L, but mine did not have a relay to switch the fan current, the thermo switch did it, to keep it more reliable and also to wire more direct supply current to the fan put in a relay if not already there.
I could tell that the fans ran with more gutso after rewiring with relay. Also then is easy to wire a dash mounted switch in parallel to the thermoswitch, you only need light wire for that, as the relay coil takes only about 0.2Amp.
Each fan runs to nearly 10amps.

[subanator]

Hey treat yourself lucky that it was still reading in the RED.
The worst thing that happens after that is all the water will boil off and no coolant flow at all, then the temp gauge will actually read near nothing until it reads transmitted heat via the block, and by then its usually all over - smoke, knocking, stalling etc.

In the MY the thermo switch for the fans is a single pole type, the L's had a twin pole similar lookin unit. Real easy to get a relay to hook up to that type. I had done it to my MY and used negitve switch via a relay to get the fans to cut in manually

[Kezpipa]

I took it in to the mechanic's (the Clayton place) and they're going to send the radiator in for a 'clean', which was a bit unexpected moneywise, but has probably needed doing for a while. It's a sh*t not knowing what your car's been through for the first 15+ years of its life!

Plus that whole fraying clutch cable thing needed doing eventually.

Subnator - for sure - I'm pleased the temp gage was reading at all, or I should say, reading close to the correct temperature. It usually sits at just over halfway, which the previous owners said was the expected... but the first thing I thought when it was in the red was 'Oh thank god, at least I know something's going wrong'.

Thanks for the tip on the relay, I don't think I could do that myself if there isn't one in already, but it's worth asking about.

Again, thanks for all the information and replies people. I must sound pretty ungrateful taking it in (to mechanic's) instead of trying out all the ideas, but I suppose it's taking me a while to pick up a basic knowledge level of my car. I guess it comes from not hanging out with enough ... er, not 'petrolheads', but I guess you'd say 'home mechanics'. Cheers in any case

[KERRY]

I also had an overheat on idle the other day.

The air cond was on and I checked the fans. I noticed the engine fan as opposed to electric spun freely when engine was off ?? are these a thermo type fan as well, maybe the hub is not working.

I had been parked and left the air on for the wife while I went to some shops, when I got back it was not on the red but on its way.

I may hardwire the electric fan to a toggle switch on the dash, then I can manually turn it on when I park and idle car for a shop trip.

We have been hitting the mid to high 30's up here in Central Queensland. all other ideas welcome, maybe add an external Davis Craigie for extra cooling ??

[mattims]

my car always used to overheat idling with the aircon on, on a hot day. The engine fan should spin reasonably freely when the engine is off. It all sounds normal to me. Just check that the electric one does turn on with the air-con.

[KERRY]

Thanks Mattims, I am going to hook up an off/on override switch on the electric. This way I can be sure it is on when the air is on, actually up here the air is always on..lol..37degrees today

[KERRY]

Just thought I would add the result of the bypass switch for those still following this thread.

Yes it still heats up on idle and below 40kph with air cond on. But the switch keeps the fan on when the air is turned off and the temp drops to normal at slow speed and idle, just turn air off !

So I went to our local 4wd track (Byfield Nat Park, Nine mile beach) to test it out.

Through the soft sand and driving slowly it overheated as expected with the air on.

While driving under 40kph through soft sand, it retuned to normal temperature, when air was turned off and fan switched on, even in soft sand.

Conclusion is that if you want the air on when hacking through sandy trails at speeds less than 40kph, expect to overheat.

Use a bypass switch so the fan stays on when air is off, and it will return to normal while still hacking through soft sand, just wind down the windows for a while then turn back on when cools down.