Urgent HELP...Maybe radiator?

[The Great Pretender]

Hi
Mmmm Aethelric..seems like a spate of Bongoraditis at the moment...we've all caught a coolant virus. I now realise why the Bongo sludges up at the bottom of the radiator, as it only works on stop -start journeys at the bottom, and on long journeys, it manages to stay cool without using the bottom half of the cooling system, as the thermostat will stay closed....unless I am reading it all wrong.....oh for the far off days of yesteryear when cars was cars
Cheers
Helen

I think your reading it right Helen, all the tests so far point to it doing that, even without a stat in the inlet.
I dont know what % of anti-freeze you require over there but keep it to around 30-40% as higher amounts can affect heat transfer. When you get up and running it is worth checking the head is free of air for a few weeks at least when you check the oil.

[dandywarhol]

I'm going to do some tests on the new one and the old one and will put the results on line.

Dave

Are you going to take a hacksaw through the old one Dave?

[vanvliet]

This is becoming more interesting that the Forensic science TV progs !
Can the cause be found before the bongos blow? keep at it lads ( and lassies )

[brorabongo]

I'm going to do some tests on the new one and the old one and will put the results on line.

Dave

Are you going to take a hacksaw through the old one Dave?

I've STILL got my old rad Dandy, Would you like me to take it down for a public disection, at Kinnloch Rannoch? Thats if I make it down.

[Aethelric]

I'm going to do some tests on the new one and the old one and will put the results on line.

Dave

Are you going to take a hacksaw through the old one Dave?

I really hope the tests will prove that its not as good as the new one. Otherwise its £158 down the drain. The coolant runs through aluminium vanes which are about 2mm x 26mm on the outside. Allowing for 0.5mm thickness thats only 1mm x 25mm on the inside. It would not take much to block them (after 80,000 miles and 12 years). It may well be a hacksaw investigation.

[The Great Pretender]

I'm going to do some tests on the new one and the old one and will put the results on line.

Dave

Are you going to take a hacksaw through the old one Dave?

I really hope the tests will prove that its not as good as the new one. Otherwise its £158 down the drain. The coolant runs through aluminium vanes which are about 2mm x 26mm on the outside. Allowing for 0.5mm thickness thats only 1mm x 25mm on the inside. It would not take much to block them (after 80,000 miles and 12 years). It may well be a hacksaw investigation.

In the system as the pipes (vanes) get smaller the flow speeds up, as the flow slows down in the bottom of the rad the cr*p falls out of the flow, that then blocks the vanes as the cr*p builds up. It isn't the cr*p that is the real problem, it is the design fault in the coolant system that allows this to happen.

[helen&tony]

Hi
GreatPretender...you say check the head for air for the first week or so....do you mean "burp" the bleed pipe with a funnel full of coolant?. Unfortunately, winter needs a 50% mix of coolant over here. However, at the local Shell station , there is antifreeze rated down to minus 40 , or 60 (i can't remember which)....It suggests to me that it may be another formulation which acts better at lower concentrations....I'll have to check it out, but I am wary, as Bongos come from Japan with some strange coolant in! Listening to what you say about higher concentrations of antifreeze being problematical regarding heat transfer makes me wonder, as my Father said that the bombers he flew in the 2ndW.W. ran on neat glycol in the cooling system!!!....I wonder how they managed with corrosion etc.
I always wonder , with antifreeze that's labelled "universal" whether they REALLY have the corrosion inhibiters actually sussed. When I first started driving over 40 years ago, cars were all- iron blocks/ heads, but when aluminium heads started to be fitted, there were immense problems with electrolytic action, and subsequent damage to cylinder heads,until efficient corrosion inhibiters were developed. Reading about the problems that the Bongo has , makes me wonder whether this old problem has started to rear its ugly head again as the antifreeze makers may have got a little lax in their persuance of cheaper additives.
If any of us who are changing radiators could cut our old ones up, we could , perhaps , pool the results to test what has been raised. It is my suggestion that we make one vertical cut to halve the radiator, and 2 or 3 horizontal cuts to determine where sludge is likely to collect. What do others think?
Also, does anyone know of a good cheap, reliable temp gauge so that I can fit it permanently to monitor water temp, as I'll leave the TM2 to monitor the block/ head, when I have moved the sensor.
Cheers
Helen

[dandywarhol]

In the system as the pipes (vanes) get smaller the flow speeds up, as the flow slows down in the bottom of the rad the cr*p falls out of the flow, that then blocks the vanes as the cr*p builds up. It isn't the cr*p that is the real problem, it is the design fault in the coolant system that allows this to happen.

Not a design fault - it's a maintenance problem - if the system isn't regularly serviced as the manufacturer (and ALL manufacturers recommend) then the crap will build up and cause the problems SOME owners are experiencing. If it was a design fault then ALL Bongos would overheat IMHO

[Aethelric]

Also, does anyone know of a good cheap, reliable temp gauge so that I can fit it permanently to monitor water temp, as I'll leave the TM2 to monitor the block/ head, when I have moved the sensor.
Cheers
Helen

The problem with monitoring the water temperature is trying to find a place to put the probe. One idea, which I have not tried, is a thermocouple on the bottom screw in the header tank of the haydn alarm. The screw head would need to be insulated to avoid heatloss, and the meter would need to be battery powered to avoid interfering with the haydn alarm.
Next option is to tape it onto the top hose.
There are quite a few thermometers on ebay, but check they can go up to 120C. Most only go to 70C. Some food thermometers can double as oven thermometers and go up to 300C!
Dave

[haydn callow]

Why not just put another screw into the tank ?? make sure it is 316 S/Steel.

[Aethelric]

Why not just put another screw into the tank ?? make sure it is 316 S/Steel.

Hmmmm

[helen&tony]

Hi
I'll check on e-bay, and maybe do as you say, Haydn, and use another screw.
Cheers
Helen

[The Great Pretender]

Hi
GreatPretender...you say check the head for air for the first week or so....do you mean "burp" the bleed pipe with a funnel full of coolant?. Unfortunately, winter needs a 50% mix of coolant over here. However, at the local Shell station , there is antifreeze rated down to minus 40 , or 60 (i can't remember which)....It suggests to me that it may be another formulation which acts better at lower concentrations....I'll have to check it out, but I am wary, as Bongos come from Japan with some strange coolant in! Listening to what you say about higher concentrations of antifreeze being problematical regarding heat transfer makes me wonder, as my Father said that the bombers he flew in the 2ndW.W. ran on neat glycol in the cooling system!!!....I wonder how they managed with corrosion etc.
I always wonder , with antifreeze that's labelled "universal" whether they REALLY have the corrosion inhibiters actually sussed. When I first started driving over 40 years ago, cars were all- iron blocks/ heads, but when aluminium heads started to be fitted, there were immense problems with electrolytic action, and subsequent damage to cylinder heads,until efficient corrosion inhibiters were developed. Reading about the problems that the Bongo has , makes me wonder whether this old problem has started to rear its ugly head again as the antifreeze makers may have got a little lax in their persuance of cheaper additives.
If any of us who are changing radiators could cut our old ones up, we could , perhaps , pool the results to test what has been raised. It is my suggestion that we make one vertical cut to halve the radiator, and 2 or 3 horizontal cuts to determine where sludge is likely to collect. What do others think?
Also, does anyone know of a good cheap, reliable temp gauge so that I can fit it permanently to monitor water temp, as I'll leave the TM2 to monitor the block/ head, when I have moved the sensor.
Cheers
Helen

No Helen not with a funnel, a bucket or similar with coolant in, degassing cap off, bleed pipe in bucket above the degassing tank and start engine. Have someone ready to topup tank and lower bucket below head, you will see bubbles if there is air/gas in the head. If you raise the bucket above the tank you create a syphon, thumb over pipe and fit the plug.

At 50% and above heat transfer is a problem, 30% is needed to stop corrosion, and that is as bad for heat transfer. Personally I would use 30% now and top up to 50% in winter, drain some off in spring so your back at 30%. Keep the drained coolant in a 5lt container in the Bongo just in case. Overheating in winter because of consentration isn't a problem IMHO.

At the hight the bombers were at freezing was a problem, also water boils at a lower temp the higher you get.

[The Great Pretender]

In the system as the pipes (vanes) get smaller the flow speeds up, as the flow slows down in the bottom of the rad the cr*p falls out of the flow, that then blocks the vanes as the cr*p builds up. It isn't the cr*p that is the real problem, it is the design fault in the coolant system that allows this to happen.

Not a design fault - it's a maintenance problem - if the system isn't regularly serviced as the manufacturer (and ALL manufacturers recommend) then the crap will build up and cause the problems SOME owners are experiencing. If it was a design fault then ALL Bongos would overheat IMHO

Well we have been here before haven't we.
im here on this post to try and help Helen and Tony, but if you think there isn't a design fault lets test it.

Lets start with a simple question so non technical people can understand.
If both inlet and outlet pipes to the radiator drop below the engine how does the air/gas get out of the head?

[helen&tony]

Hi
Aethelric:
i've been looking on e-bay, and there are auto. water temperature gauges, and an in-line adapter so you can cut a hose and fit it in with a couple of jubilee clips, and the sender fits in.
The GreatPretender:
Thanks ...that's true about altitude/ plane engines, but all that glycol seemed to perturb my instinct somehow.
Regarding my radiator problem...is that likely to be the only problem, as I haven't seen any obvious sign of overheating?
Interestingly, I had seen signs of "weeping" at the header/ matrix junction for a while, but with no apparent coolant loss, I wasn't at all concerned. Very many years ago I had the same on a BMW2002, and just used a "leak-stopper" , but from what I've read on the Bongo cooling system, I was dis-inclined to use one. I'll also take your tip on running 30% coolant, and topping up for winter. I check the antifreeze in the freezer, and do a specific gravity check also.
Cheers
Helen