Overheat AGAIN.

[AuldNick]

For those who dont know, I changed the head, gasket and water pump a few months ago and flushed the cooling system @ least 6 times, yes the head was cracked from No1 cylinder through to 4 so I thought my woe's were over with the new head and all.....

Gone fishing last weekend and the squib overheated again on a longish hill climb IE nutter movement with the gauge all over the place from normal to hot then to RED, FFS even the air con fans switched on and stayed on..

Any idea's? No leaks, new head, the ony "clue" is even more rusty coolant every time I flush the fekir till clear then take it for a run (ten times today).

BTW guys, sorry I missed Drumclog and hope to make the next meet though I doubt it will be in the Surf

[RodLeach]

For those who dont know, I changed the head, gasket and water pump a few months ago and flushed the cooling system @ least 6 times, yes the head was cracked from No1 cylinder through to 4 so I thought my woe's were over with the new head and all.....

Gone fishing last weekend and the squib overheated again on a longish hill climb IE nutter movement with the gauge all over the place from normal to hot then to RED, FFS even the air con fans switched on and stayed on..

Any idea's? No leaks, new head, the ony "clue" is even more rusty coolant every time I flush the fekir till clear then take it for a run (ten times today).

BTW guys, sorry I missed Drumclog and hope to make the next meet though I doubt it will be in the Surf

Did you change the radiator? I'd change it an do a coolant flush on the whole thing. See if that helps.

[AuldNick]

I hear you on the radiator Rod 'cos this is deffo like a coolant block BUT it flushes through OK 'till I take it for a blooter run and then I get rusty coolant again. Going to remove the drain plug tomoz and try a high pressure flush.

But why would the air con fans run when the engine gets HOT (with no aircon on)?

[BUSHWHACKER]

I hear you on the radiator Rod 'cos this is deffo like a coolant block BUT it flushes through OK 'till I take it for a blooter run and then I get rusty coolant again. Going to remove the drain plug tomoz and try a high pressure flush.

But why would the air con fans run when the engine gets HOT (with no aircon on)?

Do you mean the electric fan in front of the grille?

[RodLeach]

I hear you on the radiator Rod 'cos this is deffo like a coolant block BUT it flushes through OK 'till I take it for a blooter run and then I get rusty coolant again. Going to remove the drain plug tomoz and try a high pressure flush.

But why would the air con fans run when the engine gets HOT (with no aircon on)?

Lord knows why the fans would come on mate!

Also i'd change the termostat and rad cap! Costs like £27 all in from Roughtrax! Sweet simple job to change! Could help?!

[AuldNick]

Thermostat and cap done at head change.

It's them big twin fans on the almost horizontal aircon rad underneath the engine, the ones that shake the car when they kick in!

[BUSHWHACKER]

Thermostat and cap done at head change.

It's them big twin fans on the almost horizontal aircon rad underneath the engine, the ones that shake the car when they kick in!

I can't remember how the air-con fans were wired up (Binned mine three years ago!) maybe there's a temp sensor triggering the fans to come on or thn auxillary fan and the air-con fans connectors have been switched?

[AuldNick]

I'll check out the aux fan tomoz while I have the bugger up on the lift.

[nero279]

I'm sure i've read on some of the towing threads of the aircon fans coming on when it get's hot, so it might not be a problem

[AuldNick]

I'm sure i've read on some of the towing threads of the aircon fans coming on when it get's hot, so it might not be a problem

Would'nt surprise me that someone at Toyo wired the big aircon fans to help by drawing cold air down past a hot engine when the poo boils.

But why the overheat only on longish 100 mile + runs or when the mill has to work hard IE towing, low range mud or climbing big hills, and where is all this rusty "coolant" coming from???

[plumb bob]

Is it an auto, coz the trans is also cooled through the bottom tank on the rad, so if trans gets v. hot on long hill, this heat will be transfered to the rad/engine coolant.

If it's a manual, I've wasted my time writing this, and you've wasted your time reading it, and still no nearer a solution..........I'll get me coat.

[j4mie]

Take out the Rad and flush it, but be careful with the high pressure flush as if the rad has weak spots it could burst. Sounds like you could have a leak somewhere also, check all the hoses and the 2 Heater Cores (1 Behind the dash and 1 in the centre console). Dont forget to check the water pump. Enjoy.

[gwh200]

over heating

Would'nt surprise me that someone at Toyo wired the big aircon fans to help by drawing cold air down past a hot engine when the poo boils.

But why the overheat only on longish 100 mile + runs or when the mill has to work hard IE towing, low range mud or climbing big hills, and where is all this rusty "coolant" coming from???

are you getting hot air from your rear heater. if you are is it possible the matrix is knackered?

[magnum force]

Would'nt surprise me that someone at Toyo wired the big aircon fans to help by drawing cold air down past a hot engine when the poo boils.

But why the overheat only on longish 100 mile + runs or when the mill has to work hard IE towing, low range mud or climbing big hills, and where is all this rusty "coolant" coming from???

My past probs with rusty coolant was the rear heater....get rid, loop the 2 heater pipes that go under the truck.
The over heat prob (another past prob i had) try the vic fan, i ended up bolting mine up so it didnt free spin, or 200 quid for a new one.
Hope this helps ya mate.

[Vagrant No2]

I agree with Magnum regarding the rear heater giving you rusty water as they block very easy and corrode inside , no flush via rad will fully clear them.
I would not advise locking the viscous fan as they are not designed to be fully locked and have been known to shatter at high revs doing alot of damage . It does sound like the viscous coupling needs new oil .