ANOTHER OVERHEATING BONGO, HOPEFULLY SORTED

francophile1947 · Post by **francophile1947** » Thu Apr 05, 2007 7:29 pm

Extra thought, just think of all the old cars that used to overheat before the electric fan came on the scene.

Harry · Post by **Harry** » Thu Apr 05, 2007 7:29 pm

Big variation of temps in Japan

I spent the best part of 5 months overall in southern France last year in often very hot conditions most of the time. Fan came on regularly at the end of a run. Needed the bongo superb aircon system most of the time.

No probs.

Peg leg Pete · Post by **Peg leg Pete** » Thu Apr 05, 2007 7:31 pm

But if that is true Franco, the bongo does rely on the radiator, hence it is used more than the theory suggests

francophile1947 · Post by **francophile1947** » Thu Apr 05, 2007 7:33 pm

Yes Peter, but only if the engine gets hot enough to open the stat. We may well find hot bottom hoses in the summer.

Harry · Post by **Harry** » Thu Apr 05, 2007 7:39 pm

In warm weather conditions I'm certain that the radiator is an integral part of the system.

In our cool climate (particularly during the winter) the engine should dissipate its heat quite quickly when its on the move.

In winter conditions, with the rad way out front and seperate from the engine compartment I should imagine it would be prone to freezing up when motoring unless anti freeze is kept topped up and preshumably warm water circulating through....so warm water must flow through in cold conditions?

H

haydn callow · Post by **haydn callow** » Thu Apr 05, 2007 7:41 pm

again agreed,
Under normal conditions stat dosn't open, but, whilst standing at tickover and a few mins at 2500 revs , total time say 20 mins and system under pressure then stat will open

Peg leg Pete · Post by **Peg leg Pete** » Thu Apr 05, 2007 7:41 pm

I agree harry our overheating took place at Osmotherly meet last year, it was freezing cold, our stat was slow opening, radiator froze up, hence rapid boil up

francophile1947 · Post by **francophile1947** » Thu Apr 05, 2007 7:49 pm

peter humphrey wrote:I agree harry our overheating took place at Osmotherly meet last year, it was freezing cold, our stat was slow opening, radiator froze up, hence rapid boil up

This was a common problem in the old days, that's why lots of people fitted radiator muffs to the cars to stop the airflow.
Although not approved, I am rapidly coming to the conclusion that a couple of small holes in the stat is not a bad idea! - at least it would stop your above problem Peter, even if it did reduce the efficiency of the heater.

haydn callow · Post by **haydn callow** » Thu Apr 05, 2007 7:49 pm

Peter.. When your rad froze it would stop the bypass from circulating through the top of the rad so boilup. Doubt it was anything to do with stat which wouldn't open at all under these conditions. Not enough antifreeze??? 50%??

Jamesnjane · Post by **Jamesnjane** » Thu Apr 05, 2007 7:51 pm

if you look at the poll the took place most peoples bottom hose remains cold after long runs, so why does the japanesse manual written by the japanesse who designed the engine say wait for the bottom hose to warm up when bleeding the system???? its just not cricket

Harry · Post by **Harry** » Thu Apr 05, 2007 7:51 pm

Just like with the old minis my bottom hose froze last winter and we overheated after 4 miles...steam out of the header..thev lot..very alarmng.

Bottom hose was freezing cold and solid (no antifreeze in system!!!!.

Left for 20 minutes.. bottom hose normal temp and pliable.topped up coolant (with antifreeze)..end of problems.

So water must circulate through rad but maybe not under pressure.

Jamesnjane · Post by **Jamesnjane** » Thu Apr 05, 2007 7:53 pm

3 smalls holes about 2.5mm does the trick and you still get warm air temp at 1030

haydn callow · Post by **haydn callow** » Thu Apr 05, 2007 7:56 pm

Always premix your antifreez. 1, it is easier to keep track of %ages 2. more important, neat antifreeze is very thick and makes it much more difficult to bleed the system. I would think also that if you don't premix then untill the stat does one day open you are running around possibly with a weak mix

Peg leg Pete · Post by **Peg leg Pete** » Thu Apr 05, 2007 7:58 pm

I agree that the coolant was not up to strength Haydn, mechanic who should have done coolant did not mix to correct strength, hence I do my own coolant changes these days.

francophile1947 · Post by **francophile1947** » Thu Apr 05, 2007 7:59 pm

Jamesnjane wrote:im a little confused with the fact that a holey thermostat keeps the engine cool i know thats its being cooled by the radiator (as i thought all cars would) but surley if there were leaks in or out you would still lose coolant or get trapped air with a holey thermostat?? plus how does the bongo lose 60% of its heat through a red hot exhuast i hope someone can explain this. also on the thermostat theres a little hole anyway but does this close or allow water through??? maybe adding holes is just helping it along??????

Hi Harry - I think the above may explain that a small amount of water is always flowing through the radiator.