Bongo Fury

I've had some kind of problem with the cooling system. Nothing's gone bang yet, but I think something's on its way out. The temperature sometimes rises followed by gurgling in the expansion tank, followed by temperature drop - then all seems normal.
I've bled the system several times and all is ok for a while but ultimately this returns. It leads me to think there might just be a leak somewhere that gives rise to an air lock.

I've read lots on the forum about this but I want to know if anyone knows exactly what's happening at the point when the expansion starts to gurgle, and why the temp' then drops afterwards. Has the temp dropped because a) somethings sorted itself out and the engine is being cooled ok, or b) all the cooling water as naffed off and the temperature sender is giving duff information.

Thank you.

Hi amq,

We had exactly this with our Freda. We had a mechanic look over her and the only thing he could think it was was a knackered thermostat.

We put in a new thermostat and all seemed to be ok for about a week, then I notice a huge puddle underneath her. After the AA recovered me home, we had a look at the water pump and it was knackered...

We replaced this, but the damage had already been done and we had to get a new head etc.

I would suggest checking the water pump first - if it is on its way out it may be working intermittently...

Good luck, hope you don't have to fork out like we did...

Dan

Sounds like air is getting into the system to me, have you checked for leaks on all the hoses, water pump, pressure caps, rad seams, etc? ie can you see where the water is going?
Worth pressure testing the cooling system to check it's holding pressure/find leaks - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=38823
Also worth checking for exhaust gasses in the coolant.
Have you modified the temperature gauge at all so that it resensitises it ? (as standard it is fairly dumbed down so it doesn't really move once it's warmed up, until it's already overheating)
Re your question about the temp gauge readings, either case could apply, but without additional sensors it's difficult to know, I take it you haven't got a low coolant alarm? How much coolant are you losing each time?
If you keep driving it you're going to kill the head, if you haven't already, find the problem asap & sort it or get it to a bongo friendly garage that know what they're doing.

Thanks for the info,

Dan, did you replace the water pump and still find the engine fubar afterwards? Was that a big/expensive/awkward job in itself just to get the pump done? What was the final bill for a head? I take it if the head and/or gasket is gone you just get a big cloud of steam?

Kirsty, to my knowledge I have a standard temp gauge. I can't see anywhere the coolant is going and I'm not using the van often enough at the minute to work out any pattern of when it does go. I think I will try the exhaust gas test. Are the fluids you can buy for about ten quid accurate enough? After that I think its time to check the pump and/or take out the thermostat.



Andy

amq wrote: Dan, did you replace the water pump and still find the engine fubar afterwards? Was that a big/expensive/awkward job in itself just to get the pump done? What was the final bill for a head? I take it if the head and/or gasket is gone you just get a big cloud of steam?

Unfortunately, yes the engine was fubar after the water pump had been changed... our fault for still driving it! A friend of ours did the work, took him a couple of hours... think it came to about £55 including parts and labour (mates rates!)

As for the head, it came to £1005 in total. Pressure testing of old head, purchase and fitting of new head and gasket, bolts etc. Had this done in Plymouth at Bongo Bits...

An expensive problem, but (touchwood) she now runs like a dream!

I've had some kind of problem with the cooling system. Nothing's gone bang yet, but I think something's on its way out. The temperature sometimes rises followed by gurgling in the expansion tank, followed by temperature drop - then all seems normal.
I've bled the system several times and all is ok for a while but ultimately this returns. It leads me to think there might just be a leak somewhere that gives rise to an air lock.

I had this.

Turned out to be a crack in the water pump in the end......cost me a head gasket.

Don't drive it until you get it sorted. Much cheaper to get a new water pump, or replace all the hoses etc. than a blown head gasket.

amq wrote:I've had some kind of problem with the cooling system. Nothing's gone bang yet, but I think something's on its way out. The temperature sometimes rises followed by gurgling in the expansion tank, followed by temperature drop - then all seems normal.
I've bled the system several times and all is ok for a while but ultimately this returns. It leads me to think there might just be a leak somewhere that gives rise to an air lock.

Whatever advice you get on here, bottom line is there is a potentially serious problem in there which could be a quick cheap fix or a £1000+ bill if you keep using it as it is.

Strongly suggest you get local help from someone experienced in how these things are supposed to work before driving it too far.