3.0l Cracked head or fan?

[2 Dogs John]

We've recently bought our first Toyota Hilux '94 3.0TD, auto. We've been having overheating problems, which from reading the various threads seems to be a common problem. The temperature gauge remains constant all day long even in standing traffic and for hundreds of miles at a time. Then out of the blue, it rises, usually induced by going up a hill or increasing the speed. The temperature rises quickly but just as quickly cools down again. Several times we have been told that it must be a tiny crack in the cylinder head but none of the evidence convinces me, especially after reading the forum. Does anyone know if I can rule out the cylinder head theory especially as there is no loss of coolant or contamination from oil or water.
Having read the relevant threads on changing oil coolers and radiators, my only other thought is the fan. Does anyone know how to test the viscous fan and what is the proceedure for changing the oil and what sort is it.
If anyone knows the french for all of this we would love to hear from you.

John

[paulh]

Hi John
Sorry I don't know any French but your problem sounds very much like a sticking thermostat I had a similar problem (not on Surf) and found it to be caused by a small piece of gasket which was jamming the stat, simply removed the offending piece and refitted the stat, problem solved.
However in your case I would recommend renewing the stat as it's not so easy to get at.
Hope this helps.

[2 Dogs John]

Thanks for your reply, one of the first things we did was to drain and flush the system and change the thermostat for a brand new one. Slightly better but temperature still rises.

[stara]

examiner le ventilateur visqueux
avec le froid de moteur, il devrait être facile tourner le ventilateur avec la main.
avec un moteur chaud, il sera difficile tourner le ventilateur avec la main


1.engine cold, fan can be spun by hand easily
2.engine hot, fan will be difficult to turn by hand
perform these tests with the engine switched off.

[stevo]

rad fan

Thanks for your reply, one of the first things we did was to drain and flush the system and change the thermostat for a brand new one. Slightly better but temperature still rises.

Do a search on Viscous Fan coupling overhaul, it will show you how to strip and overhaul and adjust the fan coupling.
Cheers Steve.

[Rob]

We've recently bought our first Toyota Hilux '94 3.0TD, auto. We've been having overheating problems, which from reading the various threads seems to be a common problem. The temperature gauge remains constant all day long even in standing traffic and for hundreds of miles at a time. Then out of the blue, it rises, usually induced by going up a hill or increasing the speed. The temperature rises quickly but just as quickly cools down again. Several times we have been told that it must be a tiny crack in the cylinder head but none of the evidence convinces me, especially after reading the forum. Does anyone know if I can rule out the cylinder head theory especially as there is no loss of coolant or contamination from oil or water.
Having read the relevant threads on changing oil coolers and radiators, my only other thought is the fan. Does anyone know how to test the viscous fan and what is the proceedure for changing the oil and what sort is it.
If anyone knows the french for all of this we would love to hear from you.

John

Same symptoms as I had when my rad was about 65% caked in mud (for about 3 months til I got round to cleaning it). So, could be that or possibly clogged up inside therefore reducing the flow and heat dissipation. Or as you said, possibly the fan but then I wouldn't have thought that would have made much difference to the amount of air flowing over the radiator once you reach out of town speeds. Might be worth taking the rad to a rad specialist for inspection and testing.

[2 Dogs John]

Thanks for the french! ça m'a aidé beaucoup, merci.

[NiftyNev]

If you have some spare time read this -

http://toyotasurf.asn.au/forum/viewtopic.php?t=195

Neville

[bigbricars]

Same symptoms as I had when my rad was about 65% caked in mud (for about 3 months til I got round to cleaning it). So, could be that or possibly clogged up inside therefore reducing the flow and heat dissipation. Or as you said, possibly the fan but then I wouldn't have thought that would have made much difference to the amount of air flowing over the radiator once you reach out of town speeds. Might be worth taking the rad to a rad specialist for inspection and testing.

hi
i agee with rob i found out that the japs use very thin cores in there rads and clogg up very easy,i took my rad and had it re,cored it cured the problem.

i had the same probs as john

[Albannach]

Wow! Just WOW!

[gwh200]

Wow! Just WOW!

Oh my!