Overheating

[dogzdinner]

I have noticed a long thread concerning fans, temperature gauges and heads etc. This one is a mixture of the three! Since obtaining my '91 2.4TDI Surf 8yrs ago, I never had any probs until last year when it all kicked off bigtime. The temp gauge had stayed always just below halfway, whether with or without caravan in tow and no matter what the external conditions were doing. For some reason, this changed last June but only when towing my caravan. Providing I remained on the flat or went down hill everything worked fine but the minute I started to increase revs, up the temp started to creep until just outside the red when the stat opened or the fan bit more and it cooled slightly. However (there's always a soddin however ain't there!), last October I was stuck in a 15 mile M1 tailback, all uphill. Without any warning the gauge went off the end and wrapped itself against the end stop. Off I pulled and completed the journey via the AA! Result at t'other end? Very badly cracked and burnt head. New head etc - £700 including labour. Non-Toyota type head = £400 or so from Milner Off Road, Matlock, Derbyshire. Very good Surf/4Runner parts dealer. 3 weeks later went back down south and the sod started again halfway home. Outside temp around 1 deg C so not exactly hot. Nursed it home by keeping the revs down and avoiding stress on the engine. Took the van off and gave it a run - no probs AT ALL. Thrashed it next day and could I get the temp up? The hell I could! Gauge would not budge past halfway. That was last trip for winter and out came the van last weekend. All was well until hit the hills near Gatwick and up the temp came.... Nursed it to camp site and again with van NOT on tow, no probs at ALL. On way back there is one hell of a hill and temp was creeping up. The car is in overdrive mode by the way and was for all previous occasions. Halfway up the hill, Surf (auto box) changes down, revs shot up and guess what? Something kicked in bigtime because the temp dropped like a Tony Blair lead brick. Tried it back in o'drive and temp crept up again so switched out o/drive, up came revs, down went temp! For rest of journey home, I kept it out of o/drive and it pulled like a cracker easily hitting 60 UP HILL - no mean feat with a double axle Senator 5000 van on the back PLUS a loaded Surf! Temp rock steady! Got home and no probs at all with or without o/drive now van is off. Chum of mine has similar problem with his 3 litre 4Runner. Anyone else experience this? Anyone any ideas on this phenomenon?

[da SLUG man]

I have noticed a long thread concerning fans, temperature gauges and heads etc. This one is a mixture of the three! Since obtaining my '91 2.4TDI Surf 8yrs ago, I never had any probs until last year when it all kicked off bigtime. The temp gauge had stayed always just below halfway, whether with or without caravan in tow and no matter what the external conditions were doing. For some reason, this changed last June but only when towing my caravan. Providing I remained on the flat or went down hill everything worked fine but the minute I started to increase revs, up the temp started to creep until just outside the red when the stat opened or the fan bit more and it cooled slightly. However (there's always a soddin however ain't there!), last October I was stuck in a 15 mile M1 tailback, all uphill. Without any warning the gauge went off the end and wrapped itself against the end stop. Off I pulled and completed the journey via the AA! Result at t'other end? Very badly cracked and burnt head. New head etc - £700 including labour. Non-Toyota type head = £400 or so from Milner Off Road, Matlock, Derbyshire. Very good Surf/4Runner parts dealer. 3 weeks later went back down south and the sod started again halfway home. Outside temp around 1 deg C so not exactly hot. Nursed it home by keeping the revs down and avoiding stress on the engine. Took the van off and gave it a run - no probs AT ALL. Thrashed it next day and could I get the temp up? The hell I could! Gauge would not budge past halfway. That was last trip for winter and out came the van last weekend. All was well until hit the hills near Gatwick and up the temp came.... Nursed it to camp site and again with van NOT on tow, no probs at ALL. On way back there is one hell of a hill and temp was creeping up. The car is in overdrive mode by the way and was for all previous occasions. Halfway up the hill, Surf (auto box) changes down, revs shot up and guess what? Something kicked in bigtime because the temp dropped like a Tony Blair lead brick. Tried it back in o'drive and temp crept up again so switched out o/drive, up came revs, down went temp! For rest of journey home, I kept it out of o/drive and it pulled like a cracker easily hitting 60 UP HILL - no mean feat with a double axle Senator 5000 van on the back PLUS a loaded Surf! Temp rock steady! Got home and no probs at all with or without o/drive now van is off. Chum of mine has similar problem with his 3 litre 4Runner. Anyone else experience this? Anyone any ideas on this phenomenon?

i'd imagine something to do with transmission oil temperature rather than water temperature... but the oil cooler is inside the main rad, so the head is transferred to the water... there should be an AT temp light though??
have you checked the A/T fluid level?
Changed / Flushed AT fluid?
i would recommend getting a seperate oil cooler if you're doing a lot of towing, and i'm sure someone will paste a link to someone who sells them!

but this seems the most obvious cause to me at the moment.

[da SLUG man]

not sure on the 2.4, but on the 3ltr there is a cooling problem in the the oil cooler (inside main rad) partially obstructs the water entry to the rad!... strange design!... so the ones i have seen changed usually go for a manual rad (i.e. no oil cooler) and an oil cooler separately.

[stara]

also, it may sound obvious, but is your viscous fan up to the job, i can hear mine 'engage' when driving up hill.

[dogzdinner]

Thanks for those two Matt and Simon. Will also pass them on to my chum who has similar probs with his 3litre 4Runner. One for you Simon if I may...What does the noise of the fan engaging sound like? I have so many damn noises (excluding kids arguing, dogs barking and missus nagging). Don't think I have heard anything kick in so maybe that's the problem. But as I say lots of other noises, slightly deaf, especially in left ear so's I can't hear 'er too much!!!!
Thanks again.

[stara]

it's a pretty distinctive continuous wooshing sound like heavy wind blowing, you can tell immediatley if the fan is engaged

[europa88]

I have noticed a long thread concerning fans, temperature gauges and heads etc. This one is a mixture of the three! Since obtaining my '91 2.4TDI Surf 8yrs ago, I never had any probs until last year when it all kicked off bigtime. The temp gauge had stayed always just below halfway, whether with or without caravan in tow and no matter what the external conditions were doing. For some reason, this changed last June but only when towing my caravan. Providing I remained on the flat or went down hill everything worked fine but the minute I started to increase revs, up the temp started to creep until just outside the red when the stat opened or the fan bit more and it cooled slightly. However (there's always a soddin however ain't there!), last October I was stuck in a 15 mile M1 tailback, all uphill. Without any warning the gauge went off the end and wrapped itself against the end stop. Off I pulled and completed the journey via the AA! Result at t'other end? Very badly cracked and burnt head. New head etc - £700 including labour. Non-Toyota type head = £400 or so from Milner Off Road, Matlock, Derbyshire. Very good Surf/4Runner parts dealer. 3 weeks later went back down south and the sod started again halfway home. Outside temp around 1 deg C so not exactly hot. Nursed it home by keeping the revs down and avoiding stress on the engine. Took the van off and gave it a run - no probs AT ALL. Thrashed it next day and could I get the temp up? The hell I could! Gauge would not budge past halfway. That was last trip for winter and out came the van last weekend. All was well until hit the hills near Gatwick and up the temp came.... Nursed it to camp site and again with van NOT on tow, no probs at ALL. On way back there is one hell of a hill and temp was creeping up. The car is in overdrive mode by the way and was for all previous occasions. Halfway up the hill, Surf (auto box) changes down, revs shot up and guess what? Something kicked in bigtime because the temp dropped like a Tony Blair lead brick. Tried it back in o'drive and temp crept up again so switched out o/drive, up came revs, down went temp! For rest of journey home, I kept it out of o/drive and it pulled like a cracker easily hitting 60 UP HILL - no mean feat with a double axle Senator 5000 van on the back PLUS a loaded Surf! Temp rock steady! Got home and no probs at all with or without o/drive now van is off. Chum of mine has similar problem with his 3 litre 4Runner. Anyone else experience this? Anyone any ideas on this phenomenon?

Some people who tow regularily with the surf auto recommend using the ECT in the on position, apparantly this puts less strain on the autobox. I would also invest in a transmission cooler they can be got from Demon Tweeks or other motorsport outlets!

If you do away with the auto rad and fit a manual one, the additional air to oil cooler must be quite substantial if you are considering towing in a country where the ambient temps are higher than the uk!

Is your mates 4-runner diesel or petrol? manual or Auto?

[Rob]

not sure on the 2.4, but on the 3ltr there is a cooling problem in the the oil cooler (inside main rad) partially obstructs the water entry to the rad!... strange design!... so the ones i have seen changed usually go for a manual rad (i.e. no oil cooler) and an oil cooler separately.

Just before the 3rd gen owners start worrying, I believe this issue is with the 2nd gen 3.0 and NOT the 3rd gen 3.0.
Carry on....

[dogzdinner]

My thanks to all who have contributed - I certainly have a lot to think about. One other mentioned to me concerns the vanes on the rad and in particular the soft copper ones on top. It would seem that if these vanes get bent then it can have a drastic affect on the fan. Well will try all the non-dosh involved ones first, eg check viscous fan out and have been told how to do that with it in situ - do a taxi driver's winter warmer and stick cardboard in front of rad with the lid down. Keep revs med high but steady and wait for temp to rise. When this does get out and take out cardboard ****** quick. If unit is ok then it should kick fan in within a few seconds. Will see how we get on..... Thanks again to you all.

Regards

Dogz