ANOTHER OVERHEATING BONGO, HOPEFULLY SORTED

Dannyboy · Post by **Dannyboy** » Wed Apr 04, 2007 3:30 pm

Hi Jamesnjane,

I've had an overheating problem which is probably much the same as yours. I could also sort it by using a holey thermostat. You mention having read a thread about mine in which I was concerned about the temperature gauge not registering. I started off with eight small holes which were too many. I then pop rivetted three and tried again. This time the temperature gauge would register but only on long uphill stretches.

I agree with others who think it would be best to address the underlying problem. I have checked my entire cooling system and as far as I can see there are no blockages anywhere. All the water channels are large and blocking is unlikely, except in the rad where the water channels are very narrow.

I ordered a new rad and fitted it today. Have bled the system, even managed to get the lower radiator hose to warm up and have taken it for a test run. It seems fine, but I will not be sure until it has been driven a few more times from cold.

For Vanmaneric, after bleeding, the bottom hose was hot, and the steel pipe which leads into the thermosat from below was too hot to touch. When I got back from my run, with presumably the radiator working properly, both pipes were cool. I expect this is the way they are meant to be.

I weighed my new radiator - about 4 kilos. My old one was over 5 kilos. A kilo of gunge could easily affect its cooling ability.

I hope this is of interest. I'll let you know if my overheating problem returns or has been sorted.

francophile1947 · Post by **francophile1947** » Wed Apr 04, 2007 3:58 pm

Hi Dannyboy
I think it's fair to say that we all hope your problem is solved - keep us posted.

mikeonb4c · Post by **mikeonb4c** » Wed Apr 04, 2007 4:45 pm

That is indeed EXTREMELY interesting Dannyboy - fantastic / invaluable bit of feedback. Just to remind myself (and others), did you say the water coming out of the old one was clear when you flushed it. Because if so, it shows that the crud can conceal itself and resist flushing. And as we've always known, there is nothing worse than crusty crud stuck in your system.

Sincerely hope this is the end of the problem. Have you fitted / will you be fitting a new thermostat (without holes) to top the job off?

Best

Mike

Dannyboy · Post by **Dannyboy** » Wed Apr 04, 2007 5:38 pm

That's right Mike,

I have flushed a vast amount of water through my system, well my bongo's system, in the last couple of weeks and it all looked clean and clear. The thermostat is new and unadulterated.

I still don't understand why it doesn't overheat with a silted up radiator and a holey thermostat, but not with a silted up radiator and a normal thermostat. Logic tells me that the thermostat should open when the water round it is at the correct temperature and then there should be little difference between a holey and non-holey thermostat.

I'm just back from a second run with no overheating, so things are looking good. Tomorrow morning will be the big test however.

I'll keep you posted.

Jamesnjane · Post by **Jamesnjane** » Wed Apr 04, 2007 5:39 pm

dannyboy are you running your new rad with or without a holey thermostate???

Jamesnjane · Post by **Jamesnjane** » Wed Apr 04, 2007 5:48 pm

forget the last you just answered my question just before mine went out, ill be getting a new rad when funds allow i think, getting a new windscreen tommorow morning.

Dannyboy · Post by **Dannyboy** » Wed Apr 04, 2007 5:52 pm

Jamesnjane,

I only needed a holey thermostat to address my overheating problem. Now I've fitted a new radiator a non-holey thermostat seems to work. If it works OK later this evening and again tomorrow morning I'll be satisfied that things are OK.

Good luck, I'll let you know how it goes.

I got the Rad from Dave at Vospers in Exeter. £126 less 7% as Bongo Fury member + £8.50 Delivery, all + VAT. The best price I could find. It looks fine.

bongoing-mad-simon · Post by **bongoing-mad-simon** » Wed Apr 04, 2007 6:11 pm

Hi Dannyboy
glad to hear that hopefully your now sorted keep us informed. hope you have many miles of enjoyable motoring

_______________

simon

I'm bongoing mad R U?

Peg leg Pete · Post by **Peg leg Pete** » Wed Apr 04, 2007 6:57 pm

hope it is sorted now

Vanmanerik · Post by **Vanmanerik** » Wed Apr 04, 2007 8:07 pm

Hi Dannyboy
Thanks for the feedback, the info we now have indicated that the radiator may be the culprit but there is still the mysstery of why your holey themostat worked OK with a possible silted up radiator.
I am rather worried that under your new setup you say the top hose and bottom hose are now warm, I would have expected the top hose to be hot and the bottom hose warm. Its early days yet so we all look forward to you reporting back over the next week or so, if thats OK with you, and then we can all have a good idea of needs to be done.
Thanks,
Vanmanerik

Dannyboy · Post by **Dannyboy** » Wed Apr 04, 2007 9:09 pm

Vanmaneric,

Sorry, when I said both pipes were cool, I meant both ends of the lower radiator hose. The end at the radiator and the metal pipe where it enters the therostat housing.

The top radiator hose is hot and the bottom hose is cool. I think that is how is meant to be. Maybe the reason for this is that the radiator is very large and hence very efficient.

Like you I don't really understand why the holey thermostat seems to work so well. But at least the problem may have been resolved.

Thanks for your interest.

Dan

Vanmanerik · Post by **Vanmanerik** » Wed Apr 04, 2007 9:44 pm

Hi Dan,
This is very good news, it looks as if the system is working correctly at last, can you keep an eye on it and let us have some feedback in a few days/weeks time. Thanks for your assistance on this one.

antique · Post by **antique** » Thu Apr 05, 2007 7:34 am

hi danny boy the problem we have always found with jap imports is there antifreez, it blocks the rad cores ,it sets like araldite i advise any person that buys a jap import to have the rad flow tested ,the milage does not matter ,flushing will not cure it , a new rad will save you a fortune in the long run ?

Dannyboy · Post by **Dannyboy** » Thu Apr 05, 2007 10:10 am

I'm not a happy bunny.

The bongo worked fine yesterday. Drove it on three separate occasions, allowing it to cool between each.....no overheating....temperature gauge at about 11.30.

Out this morning.... engine overheated. Back to the drawing board. Any hints on where to get a pressure gauge to test for pinhole leaks in the hoses? Can someone also let me know if the coolant level in the header tank is the same when the engine is cold or hot. Mine seems to be higher following a run.

Ah well, if all else fails I'll run it with a holey thermostat. It would be nice to get to the bottom of the problem though.

mikeonb4c · Post by **mikeonb4c** » Thu Apr 05, 2007 10:49 am

V sorry to hear that DannyBoy. The new rad. was the right thing to do regardless though - no doubt about that.. It could be (though I wont get my hopes up) simply now an issue of getting the system thoroughly bled. the other interesting thing to consider perhaps, from what antique has said, is whether crud has set solid anywhere else. If so, is there anything that might shift it. I cant believe there isnt some chemical that would loosen it back into suspension for flushing out. I'm going to PM bj4 just in case he might be able to tap into any Japanese mechanics experience of this kind of problem. I think we may just - in the end - nail this one down to the great benefit of all Bongo owners. The work you have done is invaluable (if costly for you, which is a b*gger but draw a line and move on etc.)

Good luck with nailing the little blighter

Mike

ANOTHER OVERHEATING BONGO, HOPEFULLY SORTED

New Radiator

Hot Engine

over heating