coolant flow - (follow up to cooling diagram)

[dandywarhol]

How about fitting a thermostat on the outlet from the head?

Heat exchanger bumf here
http://faculty.virginia.edu/ribando/modules/HXphotos/

And a pic of a discected matrix - the "twisties" are known as turbulators in the industry


and a pic I put up a while back about the differences between a cheopo aftermarket radiator and an original in terms of heat dissipation

[Northern Bongolow]

in my opinion the head can get taken out in different ways,as you stated it could be catasrophic loss,but the usuall way is a slight prolonged loss.usually related to the number of cycles the engine has made.the motor warms up leaks under pressure,pressure drops,cools,and as the system cools it sucks in a little air.this can be from a bad clip,or holed pipe.etc
this air then accumilates and either blocks flow,or goes to the head.
depending on the amount of air,the motor continues toward meltdown.
the leaks are usually started by overpressure of the system,via a stat fault,this pressure raises the load on the entire system,and finds the weakest spot in the loop,if your hoses are good it may pop the rad.if your rad is good then it may make the pump leak.
the key to it all is the stat.
i will get my coat.im off to the shed

[Northern Bongolow]

been out to the shed----- the rear heater has vertical veins. in line with the inlet outlet looks like it will contain about 1-2 litres.pics to follow if needed

[Ron Miel]

been out to the shed----- the rear heater has vertical veins. in line with the inlet outlet looks like it will contain about 1-2 litres.pics to follow if needed

I seem to remember Kirsty came up with a much lower figure, when she removed hers. 160ml springs to mind - but my memory's so dodgy nowadays that could equally well be the displacement of water by a goldfish whizzing round its bowl fast, trying to get back to where it started before it forgets what it's doing (I know that feeling well!).

Liking your explanation of the effects of gradual coolant leaks/air substitution, on resulting head failures etc. I'm sure that's right, as well as the catastrophe route - I just think I had read more about catastrophic coolant loss head failures, apparently just due to simple bursting of old components. Hmmmhh1 The thermostat eh? Intended to change mine anyway (with a Mazda one), when I do the hoses shortly. No more aftermarket stuff for me, if I can get Mazda bits - ditto re heater matrices and rads, dandywarhol's diagram as case in point.

[Ron Miel]

Gotcha Steve! Teased it out of you eventually! EDIT: I suggest that your sensor-bleed might cut out all the high revving (and yes, that is a nuisance to neighbours) but only testing will prove that - how about heater-trapped air, etc.?

Gonna put a pic up soon - very rough - cobbled together from different sources - but I think it may give you an idea of where my brain is at.

Agree - needs testing, so I was going to ask Ady if he would help me out. Why Ady? He has bled my Bongo before, made a good job, and I trust him.
What I was thinking of was:
1 - Carefully remove into a container a large volume of coolant.
2 - Fit the unit
3 - See how much coolant I can get back into the system.
any residue would represent trapped air. (heaters?)
If things don't go according to plan A, then it can be bled as normal and the idea put in the bin.
Upside is that I'll have a sensor unit.

That's a good way to check for trapped air - will do likewise when I change my hoses.

Incidentally, it was the large amount still remaining in a 13 litres new coolant pre-mix container I supplied to the "Bongo friendly" who fitted silicone hoses/changed coolant for me in August, that first alerted me to the fact he had either drained down inefficiently, or failed to properly bleed the refill, or both.

Think it was both, as the coolant now in there, which still continues apparently slowly self-bleeding/de-gassing and, despite 600ml neat anti-freeze top ups so far, is still at only 29 C frost protection level versus the 36 C of the mix I provided!

[Northern Bongolow]

although the phisical size looks like it will hold lots,the rear heater actually as ron/kirsty says hold just short off 200ml.and the one i have spare has shockingly bad flow through when filled.

[widdowson2008]

OK - this was the idea - right or wrong?
The first frame shows air trapped in the head after initial filling, and this will ALWAYS be the case.
By fitting the adaptor, it provides a high point to release this trapped air, and I can't see why this wouldn't work - open to suggestions.
The hole is pre-tapped to suit the sensor (supplied within the £10). Of course, you don't have to fit the sensor. It could just be plugged with an appropriate pipe plug.

It just seemed to me to be a very easy way of getting rid of the air trapped in the head and the upper section of the radiator top hose.
I'll leave now before the ***t starts to fly.


edit - whilst I was away doing this, There was a flurry of activity so I'm going back for a read.

[dandywarhol]

I understand the theory but don't see why it is needed if the bleed pipe is held higher than the head and the pump/convection process expels the air. How are you going to ensure no air enters the sensor point when you refit the sensor?

There's a HUGE amount of work going into this and its a really excellent way to let peeps without the mechanical knowhow/facilities to actually see how the system works ..................but are we trying to reinvent the wheel? A properly maintained cooling system, free from silt and crud works perfectly well when bled the Factory way - thousands of Bongos are proving that, including my old one which is still going strong with day to day use.....................................

[Northern Bongolow]

this would work if you repeated the process several times during the bleed.but it would then be a bit risky as temps rise,unless it was fitted with an auto bleed gadget,that opens automatically when dry,and shuts when wet.these are available.

edit.
i agree with the above.

[widdowson2008]

I understand the theory but don't see why it is needed if the bleed pipe is held higher than the head and the pump/convection process expels the air.
Was trying to find a way that you can prove the air is out of the head before starting/revving the engine.

How are you going to ensure no air enters the sensor point when you refit the sensor?
Coolant will be brimming the port so not a problem I would have thought. May be wrong though.

..................but are we trying to reinvent the wheel?
Just a flight of fancy really. That's what happens when you retire, HATE gardening, and DON'T play golf. Be warned.

A properly maintained cooling system, free from silt and crud works perfectly well when bled the Factory way
Absolutely in agreement with you on that point

- thousands of Bongos are proving that, including my old one which is still going strong with day to day use.....................................
I think it's been said MANY times before - there are far more trouble free Bongos than bad uns

[Ron Miel]

I understand the theory but don't see why it is needed if the bleed pipe is held higher than the head and the pump/convection process expels the air. How are you going to ensure no air enters the sensor point when you refit the sensor?

There's a HUGE amount of work going into this and its a really excellent way to let peeps without the mechanical knowhow/facilities to actually see how the system works ..................but are we trying to reinvent the wheel? A properly maintained cooling system, free from silt and crud works perfectly well when bled the Factory way - thousands of Bongos are proving that, including my old one which is still going strong with day to day use.....................................

Agreed, although if it could cheaply/easily/reliably be done, AND would totally eliminate any need for high revs bleeding, as Steve suggested, I could see an attraction in that, from a neighbour nuisance viewpoint - but I question whether it would, due to air also trapped in heaters, etc. That's why I said much earlier that, although engine idling self-bleed and de-gas would (undoubtedly does) sometimes work, I personally would not deliberately risk it, whether in a WL-T or either of the Bongo petrol engines. I'm 99% sure that my V6 has been slowly self-bleeding/de-gassing ever since dud bleeding (bleeding dud) work by a Bongo-friendly in August, and that if I hadn't kept watching levels like a hawk I would have had a serious overheat by now (600+ml top ups so far - no leak detected, with tracer dye in use).

[haydn callow]

Dosn't the top hose where it leaves the head bend downwards very quickly ??? Those in hose adapters are 80mm long.

[widdowson2008]

Dosn't the top hose where it leaves the head bend downwards very quickly ??? Those in hose adapters are 80mm long.

It does Haydn - well spotted. Think it may actually fit in the space BUT could finish up with hose rubbing points, so perhaps not such a good idea after all.
Oh well, another one for the bin, but it got folk chatting didn't it?

Byeeee and thanks for the fun.

[dandywarhol]

I understand the theory but don't see why it is needed if the bleed pipe is held higher than the head and the pump/convection process expels the air.
Was trying to find a way that you can prove the air is out of the head before starting/revving the engine. Uhh, ok, missed that bit in the 30 odd pages I still reckon if the procedure is properly carried out with the bleed tube open from the start, trapped air doesn't stay trapped for long ergo the fart and engine damage shouldn't occur. A physical check for cold spots on a matrix will determine blockages, therefore the potential to trap air - therefore bin it for a new one - job's a carrot

[widdowson2008]

So, as I said 5 pages back (is it really that far) 'I think the subject line, 'COOLANT FLOW' is exhausted.' for me anyway. Can't think of owt else to bother you folk about on this one.

I'll can get the fact sheet sorted now based on the findings. If nothing else, this has put to rest a few 'grey areas'.

Before I go, could I interest anyone out there in a few, slightly dented items?
1 - a cylinder head (in 5 pieces). Could be re-assembled with care, (or bits would make great ashtrays)
2 - a thermostat housing in similar condition to 1 complete with a box of 'stats in various degrees of dismemberment
3 - an expansion/degassing tank (with a lump off one edge - lump included)
4 - an ECU unit ..........errrrr....... need to get permission from owner ebygum8
5 - assortment of bits that fell off the above