Coolant loss (/overheating) - any suggestions?

[Plymouth]

Last Saturday my Bongo overheated forcing me to break a journey and call out the AA. The symptoms were a temperature gauge that shot off the right hand arc of the temperature gauge, popping sounds under the bonnet and a noticeable temperature rise in the engine bay between the 2 front seats.

On investigation the AA mechanic diagnosed the problem as a faulty thermostat. He conducted a roadside repair to the stat forcing it to remain open and refilling the vehicle with coolant (here just water). This action allowed us to continue the journey and get the vehicle safely to the garage with it running at an acceptable temperature to the left hand arc of the temp gauge.

The garage replaced the temporary repair for a new thermostat and drained and refilled the coolant system. They advised me to recheck the coolant system first thing the following morning. Hands up I forgot to do this and the car overheated and I found myself back at the garage care of the AA.

The garage filled up and checked out the coolant system again and I have taken the vehicle for a longish drive and my husband has also taken the vehicle for a separate long journey. The vehicle is now running a little hotter than our recollection of how it ran previously, where my memory saw the temperature normally sit around the quarter mark of the left hand arc to now where it seems to sit just under half way across the arc. What though is most noticeable is that the coolant system still seems very thirsty. After my husband returned from a long run the coolant header tank at the back of the engine bay seemed empty requiring a litre to top it up. This is after my husband had already put in 500ml at the start of the return journey from work.

Can any one suggest what might be going on?

[missfixit70]

For a start, it doesn't sound like anyone has bled it properly when it's been refilled, this can be disastrous for the bongo, it needs to bled properly, being a fairly complex system with two heater matrixes & mid engined. Chances are it's got airlocked, the fact you are having to refill it after a run is possibly that air coming out, or it could be you've got a leaking hose/pipe/rad or worse the head's gone after the abuse it seems to have had
The temp gauge usually runs at about 11 0clock, but is dumbed down to such a degree that it gets up to temp at @55 degrees & sits there until well over 100 degrees before it'll move again, by the time it does start moving, it's already overheating, unless the gauge is modified or has a Mason alarm fitted (which modifies it to be more accurate).
It really needs to go to a garage that knows bongos, system needs pressure testing & checking over for leaks & bleeding properly at the very least. I'd be very wary of driving it anywhere until it's sorted, but I fear the damage may already be done.
Are the heaters running hot when the engine's up to temp? There are factsheets in the members area to help with bleeding etc as well as videos on youtube, but I would get it checked out properly.
IF the head has gone, you will probably not get any of the traditional symptoms associated that most garages would recognise, ie margarine in the oil filler cap, white smoke or exhaust gases testable in the coolant.
Good luck getting it sorted

[Plymouth]

Abuse! Not intentional honest. So what's the damage likely to be and what sort of symptoms could we be looking for?

[missfixit70]

Likely damage is cracked head (worst case scenario), symptoms are dropping coolant levels wuith no apparant leak, hoses may become more pressurised than normal in use, airlocks causing pressure cap to blow, slightly chuggy starts due to water in a cylinder(may be some white smoke, may not).
As I said, get the coolant system presure tested (no more than the 1.1bar header tank cap)to see if it's holding pressure & may help to track any leaks. If there are leaks & you've been running it, it means the system possibly isn't running at the pressure it should be, which means the coolant can boil at a lower temp.
I was in a simialr position last year, kept finding & fixing leaks etc, new rad, water pump, stat, hose clips leaking with silicon hoses , but after 3 months or so of fannying around I had to accept the head was cracked.
This is why it needs to go to a bongo specialist, could you get it taken to Allans? or mebe Discount trucks?
Once it's sorted get some monitoring on there, such as a low coolant alarm & temperature monitoring that tells you something useful, rather than just relying on a dumbed down temp gauge.

[321Away]

Bongo owners need to stop trusting in the recovery services abilities so much, to date i've only ever met one that knew how to bleed a bongo properly and quite a few that said they did but didnt! have even seen several with notes attatched stating 'head gasket failure/failed sniffer test', when the car only needed to be bled properly!

Think its time that ALL bongo owners made themselves aware of the basics of bongo ownership/maintenance, when unawareness (poilte way of putting ignorance! in the nicest possible sense!) can turn a low coolant/pipe burst/pin hole situation into a £1500 head replacement due to the recovery services bodged attempt at a roadside repair!

Julian

[missfixit70]

Doesn't help when some respected garages fit new heads with no bleed pipe connection to enable proper roadside bleeding if there is an issue.

[mister munkey]

I agree with Julian.

Its not a bad idea to print out the Members Area Factsheet on bleeding & keeping it in the glovebox along with a link to the You Tube videos as a precaution to avert the enthusiasm of those who should know better.

[Plymouth]

Thanks for your comments. Husband has taken it off to Discount Trucks - who believe it may be the water pump and not the head (DT having advised on phone that all should be OK driving to Newbury). On the positive side there have been no issues on starting, no smoke etc. We shall see, eh?

[missfixit70]

Fingers crossed for you , be very careful driving it there, personally I wouldn't risk it with an unknown cooling system issue. Keep us posted on how you get on, may help others in future.