confused cooling

bonewage · Post by **bonewage** » Thu Feb 14, 2008 1:03 pm

Me again, fitted replacement engine from Jap Engines, new radiator, thermostat, water pump checked, 400 miles of sweet running then overheating again, discoloured water, Garage confused by Hot top hose and cold bottom hose..any ideas.

haydn callow · Post by **haydn callow** » Thu Feb 14, 2008 1:23 pm

If your bottom hose is actually COLD (not even warm) after a run then I would suspect your thermostat has not opened. Your bottom hose should be WARM (not hot) after a run of about 20 mins.

haydn callow · Post by **haydn callow** » Thu Feb 14, 2008 1:30 pm

When it overheated did the temp gauge go into the red ? Did you lose coolant ? Does the header tank smell of exaust gas ? What is the colour of the coolant discolouration ?
Has the new engine been bled by someone who knows his Bongos ?
Questions...Questions

Peg leg Pete · Post by **Peg leg Pete** » Thu Feb 14, 2008 2:35 pm

Sounds very much the symptoms our Bongo had after a engine replacement, was not bled correctly and coolant was non existant

Water was rusty brown, thorough flush and coolant change plus the all important bleed, hope yours is that simple.

bonewage · Post by **bonewage** » Thu Feb 14, 2008 4:01 pm

Haydn, no coolant loss, never got past mid temp gauge, did not lose coolant, water brown...

haydn callow wrote:When it overheated did the temp gauge go into the red ? Did you lose coolant ? Does the header tank smell of exaust gas ? What is the colour of the coolant discolouration ?
Has the new engine been bled by someone who knows his Bongos ?
Questions...Questions

daveblueozzie · Post by **daveblueozzie** » Thu Feb 14, 2008 5:21 pm

when the coolant was replaced and you ran your engine ,did you also turn on the rear heater air con , this is a common fault some garages do not do,otherwise it does not get rid of all the trapped air,it may be quicker to replace the thermostat and maybe replace the coolant .

bigdaddycain · Post by **bigdaddycain** » Thu Feb 14, 2008 5:29 pm

Definitely ditto the above,it's easily overlooked for the rear heaters to be switched on when bleeding....but all important.

Peg leg Pete · Post by **Peg leg Pete** » Thu Feb 14, 2008 6:53 pm

Not maybe change the coolant if it is brown, You need to change the cpoolant, sorry but from experience you need good quality clean coolant in your bongo

dandywarhol · Post by **dandywarhol** » Thu Feb 14, 2008 8:58 pm

Can someone explain this "switching on" the rear heaters thing. It's my understanding that the rear heater is always "on", coolant is always circulating through it's matrix - the heater control only directs hot or cold air to the outlet vents.

francophile1947 · Post by **francophile1947** » Thu Feb 14, 2008 9:40 pm

dandywarhol wrote:Can someone explain this "switching on" the rear heaters thing. It's my understanding that the rear heater is always "on", coolant is always circulating through it's matrix - the heater control only directs hot or cold air to the outlet vents.

I thought the same

That's why there have been posts about the heater radiators doing most of the cooling under normal conditions. Is there a water shut-off valve and, if so, how is it operated? (I've never used my rear heaters, but thought they were just electric switches

)

Peg leg Pete · Post by **Peg leg Pete** » Thu Feb 14, 2008 11:22 pm

surely you have the heaters on to indicate that the coolant is circulating to the rear heater matrix and that there is no airlock back there.

dandywarhol · Post by **dandywarhol** » Thu Feb 14, 2008 11:43 pm

But my point Pete is that they are always circulating coolant - its the air flaps which direct air over the hot matrix which is then directed to the outlet vents. Air which isn't directed over the matrix is then distributed as cold (when the lever is at blue) and mixed up to a point when only hot air is fed out (position red). The fact that the heat control is instantaneous tells you it's directed air, not a water valve closing.
The days of water control valves went out with 1980s Metros........

Peg leg Pete · Post by **Peg leg Pete** » Thu Feb 14, 2008 11:56 pm

Fair comment

mikeonb4c · Post by **mikeonb4c** » Fri Feb 15, 2008 12:49 am

OK so it had a new engine but did they re-use the old radiator etc. and could it be dodgy / blocked?

daveblueozzie · Post by **daveblueozzie** » Fri Feb 15, 2008 1:24 am

I'm not very technical . but i do know that Mike at wheelquick has changed quite a few hoses and coolant over the last few month's i have been and had a word with most of the people who have had their coolant changed, and every time Mike has said, now turn the engine on and the air con and blowers on full and don't forget to put the back air con and blowers on full as well. now this is a bloke who knows the bongo engine inside out. and as far as i know no one has had any coolant problems .