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Re: Loss of water from expansion tank - advice wanted

Posted: Mon Apr 14, 2008 11:45 pm
by dandywarhol
An air flap shuts off the heat from the matrix and simultanously another flap lets cold air into the interior in all the heater boxes I've seen - I don't see that a Bongo one is any different TGP.
I see what your saying about having the heater set to hot to moniter the bleeding though. But they aren't set to hot to allow coolant flow around.

Re: Loss of water from expansion tank - advice wanted

Posted: Mon Apr 14, 2008 11:46 pm
by Simon Jones
Mike - yes have tried to bleed it as per manual, but if I ran it for 10 mins as per the instructions, I 'd have no water left in the system to bleed. I may try taking the glow plugs out tomorrow & turn it over on the starter. If there is any water in the bores, then it will blow out the holes. Trouble is, I can't work out whether the problem is in the top or bottom of the engine. Even if I took the head off again for another look, I don't think I'm going to see any signs of a problem - any water in the head will be disturbed by the removal, so will end up on the gasket / block.

Re: Loss of water from expansion tank - advice wanted

Posted: Mon Apr 14, 2008 11:50 pm
by Ian
Have you tried the "Bell Hill" test?

The best way to prove the theory is by taking the vehicle on a 30 minute run and parking it up for the night. When the engine has cooled enough to work on, remove the glow plug rail and all 4 glow plugs from the cylinders. In the morning return to the vehicle and place a strip of card some 9” by 20” across the top of the glow plug holes and turn the engine over. In doing this the glow plug holes act as vents and anything in the cylinder will be forced up through them rather than down the valves. With any luck you will have 3 black carbon marks and a larger watery mark where water has collected in the cylinder overnight.

Re: Loss of water from expansion tank - advice wanted

Posted: Mon Apr 14, 2008 11:53 pm
by dandywarhol
Good one \:D/

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 12:07 am
by The Great Pretender
Agree Dandy, the heaters always work before the cooling system does so as the demisters work first, and the heater.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 1:22 am
by Aethelric
dandywarhol wrote:An air flap shuts off the heat from the matrix and simultanously another flap lets cold air into the interior in all the heater boxes I've seen - I don't see that a Bongo one is any different TGP.
I see what your saying about having the heater set to hot to moniter the bleeding though. But they aren't set to hot to allow coolant flow around.
I think this is the usual system in modern vehicles. It was not always so. Some of my older cars, which included a Triumph Herald (nice) and a Lada (crap) had taps in the water system. When you were used to them, and moved to a more modern vehicle what was striking was how fast the temperature of the air changed when you moved the heat control. It took ages for heater matrix to cool down. The Lada heater was phenomenal BTW. You could not bear it full on in January with the windows open.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 11:29 am
by haydn callow
does anyone know what the compression ratio of a diesel is compared to a petrol engine? being a compression ignition engine rather than spark ignition. I seem to remember it is much higher and I suppose this makes them more likely to fail long term.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 12:26 pm
by mikeonb4c
Simon Jones wrote:Mike - yes have tried to bleed it as per manual, but if I ran it for 10 mins as per the instructions, I 'd have no water left in the system to bleed. I may try taking the glow plugs out tomorrow & turn it over on the starter. If there is any water in the bores, then it will blow out the holes. Trouble is, I can't work out whether the problem is in the top or bottom of the engine. Even if I took the head off again for another look, I don't think I'm going to see any signs of a problem - any water in the head will be disturbed by the removal, so will end up on the gasket / block.
Oh bum, I feared that would be the reply, but had to check.

Ian's 'Bell Hill' suggestion sound excellent and worth a try.

Like Haydn, I do wonder if the high compression ratio (said to be higher than the standard Ranger engine?) , alloy head/iron block etc. make this an engine than be quite easily upset given a certain combination of events (but what?). Otherwise (as Harry reminded me at Stainforth) it is as tough as old boots (toughest engine he'd ever seen, to use his words). If only the designer would write his memoirs and give us the full story (in English!) :lol: :lol:

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 12:44 pm
by Aethelric
haydn callow wrote:does anyone know what the compression ratio of a diesel is compared to a petrol engine? being a compression ignition engine rather than spark ignition. I seem to remember it is much higher and I suppose this makes them more likely to fail long term.
The compression ratio in a diesel engine is much higher, but its the pressure formed after ignition that forms the biggest pressure. In spark engines the fuel burns very quickly. If it detonates, i.e. all burns at once in an explosion then its know as "knocking" or "pinking". In deisels the fuel always detonates, which is why they are rougher, particularly at tickover. But they are designed to take the higher stresses and, like any engines good ones last a long time and poor ones don't.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 12:47 pm
by Simon Jones
I'm going to try to get it to a point where I can take it for a short drive & then I can try the Bell Hill suggestion. I fear that the pressure will build up & dump the water before I can get very far - that will leave me with a very dead Bongo.

I'm going to do some reading up the Ranger engine, but can anyone confirm they are different compression ratios? I understand that many manufacturers like Mercedes or VW tend to use the exact same engine, but the power is all down to differences in the ECU programming & possibly the performance of the turbo.

I can get hold of a chap who works for the commercial vehicle division of Ford, so he may also have some suggestions.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 9:43 pm
by Peg leg Pete
When I had an airlock, the heaters ran cold :roll: once bled correctly, heaters behaved :wink:

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 10:40 pm
by haydn callow
My friend in Oz has been following this post. He made the following comments...might be worth looking into.
I don't know if you have it in UK but we have a product called "Chemiweld"

I have used on engines with blown head gaskets and "mystery" leaks that the RACQ couldn't find with great success.
It is designed to seal cracks in cylinder heads and blocks.

I reckon if I were him I would give it a try as he has nothing to loose.
If it works the repair is permanent.
At least if he tries this and it fixes it it will give some indication of what the problem was.

I used it on the daughters car when she cooked it and warped the head.
She drove it for a year after until I fitted it with a new head.

Linda had a Ford Falcon which would suddenly loose coolant over night.
I pressure tested, tried everything.
The RACQ had a look as well, but could find nothing.
I Chemiwelded it and problem solved.
That was 10 years ago and the car is still running around Townsville with it's new owner of 4 years

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 10:53 pm
by The Great Pretender
If my memory still works I think the Toyota Lucida web site have hade mixed results using "Chemiweld". I suppose it depends on what it needs to do to make things better.

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 10:54 pm
by haydn callow

Re: Loss of water from expansion tank - advice wanted

Posted: Tue Apr 15, 2008 11:10 pm
by The Great Pretender
Peg leg Pete wrote:When I had an airlock, the heaters ran cold :roll: once bled correctly, heaters behaved :wink:
Ve hav Vays of making you behav but making it bleed is drastic. :-" :-" :-"