Bongo head faults

Bumbly1 · Post by **Bumbly1** » Fri Dec 21, 2007 9:39 pm

bonewage wrote:today was not a good day

For you, your Bongo or the garage? Lets hope the break over the festive season renews resolve to tackle the problem and fix it once and for all. Bon chance mon ami.

Bumbly1 · Post by **Bumbly1** » Fri Dec 21, 2007 9:44 pm

vanvliet wrote:I agree that maintenance is a major factor and poor / lack of ,probably exacerbates an underlying design fault plus the cooling systems were probably expected to last only a few years , along with the rest of the van!

I have seen no evidence to support the contention there is a design fault. I reckon, as said before, that it is a service issue for the which the manufacturer is not to blame.

mister munkey · Post by **mister munkey** » Fri Dec 21, 2007 10:15 pm

Spot on Trev.

That theory is so blazingly obvious when laid out like that!!

Thats another great aspect of this place. Getting the history & philosophy of these beasts into your blood makes it easier to understand & anticipate problems.

Well done.

vanvliet · Post by **vanvliet** » Fri Dec 21, 2007 10:32 pm

Japanese servicing - Yes ,I was told that the Japanese tend to have their vehicles professionally serviced even when they get older , which is not what happens in the UK .
Of course things will go wrong in an older vehicle but the cooling system in the Bongo seems to be particularly problematic . not least in the diagnosis of what causes the breakdown and how to fix it .Poor design? Depends on how you view the term ' design' I suppose.There are other big diesels which have longevity ( age and mileage) and seem to suffer fewer cooling problems than the Bongo and a lot of that is down to the design of the system and components - rad core /pipe runs etc A good 'design' could , for instance anticipate sludge build up .
Anyway enough of this , I am off to the pub - and I will not be driving . Cheers lads and lasses

BongoMTBer · Post by **BongoMTBer** » Fri Dec 21, 2007 11:25 pm

Any oil getting into the coolant system will cause a build up of sludge. Obviously, it shouldn't be there in the first place though. The only oil that could normally get into the system would be from the rubber hoses, where oil is used a plasticiser in the hoses. I suppose there is a lot of hose on this vehicle. They also seem to be prone to hardenning hoses, ie. when the the hose looses the plasticiser.

I must admit, I am reconsidering ownership now. If I had spent more time reading and seen all the bad on this forum before buying, I would not have gone for it.

dandywarhol · Post by **dandywarhol** » Fri Dec 21, 2007 11:34 pm

And thats precisely the point MB - you're reading all the bad stuff - people like to moan about bad stuff - it's a typically British thing to do. But it's bad stuff concerning a tiny minority of the 3,000 or so Bongos in the UK

The Great Pretender · Post by **The Great Pretender** » Fri Dec 21, 2007 11:38 pm

I have resisted putting my pennyworth into head problems and I hope I dont regret it.
There is a fault with the design and more manufactures are designing there systems the same. The only reason that I can think of for doing it is reduced emissions.
The thermostat should be on the outlet of the cylinder head. The reason for this is to restrict flow out of the head. The hottest part of the engine is around the exhaust valves, the water in the jacket around them must not be allowed to boil. If it does the excess heat can warp or crack the head.
With the thermostat on the inlet to the engine the only pressure in the system is provided by the pressure cap as the temp rises, this will not stop the water boiling around the exhaust valves. Over time the excess temp cycles cause the failures.
Now dont shoot me im only the messenger, the thermostat on the outlet of the cylinder head causes a restriction on flow out of the head (like squeezing a hose pipe). This causes the pressure in the head to increase, this extra pressure raises the boiling point stopping the water around the exhaust valves boiling increasing heat transmission.
Hope this makes sense, am on my third glass of red, wine not diesel..

mister munkey · Post by **mister munkey** » Fri Dec 21, 2007 11:46 pm

Total agreement Dandy.

The one off cost of getting your freshly adopted member of the family safeguarded against these (inititially) minor potential problems is minimal.

More than just belts, filters & oil but flushing & greasing makes a big difference for minimal outlay. I'm sure threads on here have already covered this but a checklist factsheet on BF could help new owners - assuming its not already there of course.

At the end of the day - You get what you pay for. But peace of mind is cheap.

Bumbly1 · Post by **Bumbly1** » Fri Dec 21, 2007 11:55 pm

mister munkey wrote:Total agreement Dandy.

The one off cost of getting your freshly adopted member of the family safeguarded against these (inititially) minor potential problems is minimal.

More than just belts, filters & oil but flushing & greasing makes a big difference for minimal outlay. I'm sure threads on here have already covered this but a checklist factsheet on BF could help new owners - assuming its not already there of course.

At the end of the day - You get what you pay for. But peace of mind is cheap.

100% correct, simple steps and happy motoring. Bongo is an excellent vehicle, just care for it and it will reward you many times over. Why this thread should prompt reconsideration of a purchase is totally beyond me!

dandywarhol · Post by **dandywarhol** » Fri Dec 21, 2007 11:59 pm

I'm thinking about it GP but not convinced...................

If the restriction is there to increase the pressure around the valves then I can't see how it does it. The system around the block/valves is connected to the return side of the radiator so it can't apply "extra" pressure around the valves

The only reason I can see for the 'stat on the return side is to allow it to operate at a lower temperature and therefore make it less likely to fail than running at 100 + deg.C most of the time. The wax in the stat eventually fails. Remenber the stat also has a bypass system during warm up.

Volkswagon/Audi have been doing it this way since the early 80s

Another bottle of Montana Reserve awaits.................

The Great Pretender · Post by **The Great Pretender** » Sat Dec 22, 2007 12:11 am

The restriction dosnt, it slows the flow, the heat increases pressure

dandywarhol · Post by **dandywarhol** » Sat Dec 22, 2007 12:16 am

hmmmmmmmmm ....hic.

The Great Pretender · Post by **The Great Pretender** » Sat Dec 22, 2007 12:21 am

dandywarhol wrote:hmmmmmmmmm ....hic.

Ok, so here is a little late night reading you may enjoy.

http://pass.maths.org.uk/issue1/bern/index.html

The Great Pretender · Post by **The Great Pretender** » Sat Dec 22, 2007 12:25 am

dandywarhol wrote:hmmmmmmmmm ....hic.

Bye the way.............happy 2300.............

ronhud · Post by **ronhud** » Sat Dec 22, 2007 11:10 am

I've had my Freda for 3 months now - next event will be the oil filter service. After that a main service - is there anywhere I can find a list of what constitutes a main service? and following on all the comments about preventitive measures re cooling system can anyone list the measures an owner should take for this. This forum is a major resource but sometimes I get confused by the wealth of information!

Ron

Bongo head faults

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