Help Please Caravan Nightmare Overheating

[Cornishman1]

Help Help I'm in a big dilemma.I have recently purchased a caravan which i thought my beloved surf being a 30.ltr would quite comfortably pull.
It pulled a dream,all guages good until in the distance came a hill. O dear!
The temperature guage went up into the red straight away.Broke the brow and then the guage dropped. Panic over I thought no Probs. Oh S**t another hill (well being in Cornwall and devon you expect a few) up into the red again. Same thing happened on every hill i came to.Got to my destination Woodlands from Newquay about 80 miles a big sigh of relief. Checked radiator and had to put about 2 pints of water in. Truck behaving normally unladen temperature guage fine till we came home this morning.Same thing on the return journey. Recently had a new head and gasket 2 months ago so don't want to damage engine please please acn any one suggest what might be the cause of this problem. If I can find no solution I will be forced to sell it because there's no way my wife will give up thi snew caravan.
HELP!

[stormforce]

Help Help I'm in a big dilemma.I have recently purchased a caravan which i thought my beloved surf being a 30.ltr would quite comfortably pull.
It pulled a dream,all guages good until in the distance came a hill. O dear!
The temperature guage went up into the red straight away.Broke the brow and then the guage dropped. Panic over I thought no Probs. Oh S**t another hill (well being in Cornwall and devon you expect a few) up into the red again. Same thing happened on every hill i came to.Got to my destination Woodlands from Newquay about 80 miles a big sigh of relief. Checked radiator and had to put about 2 pints of water in. Truck behaving normally unladen temperature guage fine till we came home this morning.Same thing on the return journey. Recently had a new head and gasket 2 months ago so don't want to damage engine please please acn any one suggest what might be the cause of this problem. If I can find no solution I will be forced to sell it because there's no way my wife will give up thi snew caravan.
HELP!

Hi Cornish.Have you got any airlocks in the cooling system and perhaps change the thermostat aswell.
You fancy meeting up with us next w/end at the rtts

[NiftyNev]

The answer may be here.

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

Nev

[Tallyman]

First thing is check your fan is working properly. The main overheating problem, presuming you have an automatic, is that the standard ATF oil cooler in the base of the radiator tends to re-heat the cooled water just before it goes back into the engine. A separate ATF oil cooler in line before the radiator connection will cool the fluid before it gets a chance to re-heat the cooled water.

Next make sure there are no airlocks in the cooling system, making sure that when you check or re-fill it that both front & rear heater matrixs are open so that any air can circulate and escape.

I've also fitted a botten fan to mine 3.0 and even with that and the ATF cooler and a re-oiled viscous fan mine still showed a raising of coolant temp when towing my van up the cornish hills this year, however it never got too hot and the standard temp guage never moved off of normal, even though the suppliamentary guage showed the temp moving up and down by about 10-15 degrees C on hills.

Once you've done all that you should not have any further problems.

[Cornishman1]

Hi Cornish.Have you got any airlocks in the cooling system and perhaps change the thermostat aswell.
You fancy meeting up with us next w/end at the rtts

Hi thanks have changed the thermostat when the new haed went on and not to my knowledge do i have any airlocks
It baffles me completely.

I would love to but I'm in hospital on Tuesday so will have to see how I feel but thanks anyway
Jon

[TonyN]

How heavy is the van when loaded up? More than 2000kg will require extra ATF cooling arraingments.

Our 3.0 regually gets hot when towing heavy trailers 2 tonnes and over up long hills, but you shouldn't be losing water if its not got into the red zone. I just turn all the heaters on hot and slow down and crawl to the top.

Make sure you have the overdrive switched off when towing up hills.

[Cornishman1]

How heavy is the van when loaded up? More than 2000kg will require extra ATF cooling arraingments.

Our 3.0 regually gets hot when towing heavy trailers 2 tonnes and over up long hills, but you shouldn't be losing water if its not got into the red zone. I just turn all the heaters on hot and slow down and crawl to the top.

Make sure you have the overdrive switched off when towing up hills.

Hi the caravan is only about 1200kgs loaded so shouldn't be a problem.What is ATF?. It has been in the red a few times but as soon as you break the brow and go down the other side it drops back really quite quick.

[slim]

What is ATF?.

atf = automatic transmission fluid

[marky]

Help Help I'm in a big dilemma.I have recently purchased a caravan which i thought my beloved surf being a 30.ltr would quite comfortably pull.
It pulled a dream,all guages good until in the distance came a hill. O dear!
The temperature guage went up into the red straight away.Broke the brow and then the guage dropped. Panic over I thought no Probs. Oh S**t another hill (well being in Cornwall and devon you expect a few) up into the red again. Same thing happened on every hill i came to.Got to my destination Woodlands from Newquay about 80 miles a big sigh of relief. Checked radiator and had to put about 2 pints of water in. Truck behaving normally unladen temperature guage fine till we came home this morning.Same thing on the return journey. Recently had a new head and gasket 2 months ago so don't want to damage engine please please acn any one suggest what might be the cause of this problem. If I can find no solution I will be forced to sell it because there's no way my wife will give up thi snew caravan.
HELP!

What are you towing? I hope the handbrake was off Dont floor it trying to climb big hills O/D = OFF ECT = ON is the way i tow with no problems the temp will go up on long climbs etc. I used to have 2nd gen 2.4

[MattF]

Change rad cap if it isn't new. Check ATF fluid to make sure it's in good condition,
or if you haven't had it replaced at all since getting it, get it changed. Burnt ATF
fluid will lead to higher temps. Check for airlocks. As mentioned, turn O/D off up
hills whilst towing. Using aircon? If all else fails, get rad checked and check the
operation of the viscous fan, which may be short on oil. Also, are the rad vanes
gunged up with anything, or fairly clean? Also, just as an aside, was the thermostat
a Toyota one or a compatible type? Thermostat and rad cap are two things I would
personally suggest you always replace with Toyota originals.

[BUSHWHACKER]

I think a seperate transmission cooler is needed..

[Cornishman1]

What are you towing? I hope the handbrake was off Dont floor it trying to climb big hills O/D = OFF ECT = ON is the way i tow with no problems the temp will go up on long climbs etc. I used to have 2nd gen 2.4

Very funny handbrake definatley off LOL.Trouble is mine goes into the red.
Right back to serious business, just took the truck out after filling up more water and there seems to be a small pin prick on top of the radiator just down from the rad cap.Very small that it almost evaporates on contact when outside the rad.
Also can any one tell me when the fan should cut in and what activates the fan.Can't seem to get it to work.Mind you didn't check when van was being towed. How can i tell if the fan is broke or maybe the sensor needs changing.But where is the sensor situated.
Excuse some silly questions but i have no idea that's where you experts come in.If anyone in Cornwall would like to try to fix let me know always worth a beer or 2.

[Cornishman1]

I think a seperate transmission cooler is needed..

I need a little bit more info sorry.

[BUSHWHACKER]

All explained here.....

http://www.showmesome.info/hilux/workshop/oilcooler.htm

[slim]

I need a little bit more info sorry.

if you have an auto box then the oil from that goes through the bottom tank on the rad to cool down, this can stop the coolant cooling down enough with it being so close to the atf oil as it passes through the bottom tank . so having a sepraate oil cooler or a second oil cooler will stop the oil from warming the coolant back up as it passes through the bottom tank.