Overheating and losing coolant

[colshandy]

My old thread on this titled “Overheating Issues” is locked, hence new thread.

I bought my bongo last spring and completed about 1,000 successful miles. Then in September my coolant level dropped, overheated and popped the lid off the coolant tank.

It has been in and out of the garage several times since. They have checked pump, thermostat and replaced rad. I sent them the link to bleed it properly and they say they have done this. They reckon there are no blockages in the pipework. Apparently it is showing no signs of the head gasket going.

They changed the stat to one that worked at a lower temp then did a bodge they thought might fix it (drilled holes through the thermostat!).

Same problem is still happening, temp gauge goes up towards high, kettling noise, then looses loads of water (not sure exactly how).

I am at a total loss as what to do next. any help appreciated.

Thanks

[Spencer54]

Hmmmm

Questions that need answering is where did your original coolant loss go, did you have a pipe leak?
If it popped the cap then surely that means your system has pressurised, which would suggest head gasket to me.

Drilling thermostats and all that isn't the answer - but you know that already.

So, options are:

Head is kaput
Cracked the block internally
Waterpump is not working.
You have an airlock (i.e not bled)

For starters, run the engine and check in the expansion tank for small bubbles.
Constant stream could be that your head gasket has indeed failed.

[haydn callow]

Almost certainly a new head required and I wouldn't let that garage touch it.

[Northern Bongolow]

remove the bung in the end of the bleed pipe and hold the pipe end at a level that is the same as the expansion tank cap. get as much coolant or just water at this stage into the system, you may need to massage the pipes from the head and rad to shift as much air as you can out of the system.
then fit a 2 bar pressure gauge into the bleed pipe end, and see what happens, the pressure should slowly rise with temp.
the cap blows at 1.1 bar, if the cap blows before its faulty, if the pressure rise is faster than temp then there is a chance the head or gasket is poooped.
pressure can rise really quickly if the system is not bled of all the air, any trapped air can create a hot spot and very quickly turn water or coolant in the area to steam,as it super heats it expands massively, this is what is usually seen at the cap, or even heard first.

usually in a head crack situation things are ok until a certain temp is reached then the crack opens, this can let combustion gasses or more usually exhaust gasses into the coolant galleries around no2 or no3 exhaust valve, if you have a gauge on the system you can at least see whats happening, as pressure is the whole system,where temp is only measured locally to the sender.

you must bleed the system first to get the rest right.

beware that hot coolant /steam is very dangerous as it is above boiling temps.

[colshandy]

Apparently it needs a new engine ;-(

Any for sale ?

[haydn callow]

Who said that?? The garage that drilled holes in the stat?? If so .. Get it to a garage that deals with bongos..

[Bob]

Trust me, peeps on here worth listening to.

Good luck getting sorted.