Coolant / heating

[tjbrookes2004]

Hi , I've recently got a bongo . Having heard nightmare stories about overheating , my problem is
Engine gets to normal temp but does not overheat but my heater doesn't blow out hot air at all , I noticed the coolant is really mucky

[tjbrookes2004]

Oh and my bottom radiator hose takes forever to warm up

[Bob]

Welcome aboard.

It's possible the rod that operates the heater flap, in the driver's footwell, has become detached, or the heater matrix may be full of crud.

Does the rear heater work?

I'd certainly get the system flushed and refilled and bled.

Which engine do you have?

[tjbrookes2004]

Hi , I have a 2.5 diesel and both the heaters blow cold air not hot

[turfite9999]

Hi
I am no expert but if the Bongo is idling it is hard to get temperature up, similar to a ford transit, what I did when I was bleeding the system was to keep the revs up for a good few minutes keeping eye on tempreture gauge, the tempreture then rises and hopefully the fan will kick in. Hope this helps,

Tony

[g8dhe]

It takes a good 10 minute drive around town before the temperature starts to even climb on a standard gauge. Best to check if the flow into the heater matrix is at the expected temperature, of if its cool because of lack of flow thru the matrix. The temperature control is carried out on the air side not the coolant side of the matrix so there should always be a flow and once the engine is up to temperature it will be hot.

Its quite common to find that sellers have removed the thermostat when there is a known overheating problem It won't show in a short test drive of course so you only find out well after the sale has been completed when the temperature gauge doesn't move or you start investigating other coolant problems

[haydn callow]

It can take 40/50 mins of quite aggressive revving to get the bottom hose to go hot (it does that when the stat finally opens)

[tjbrookes2004]

Thanks for the info , gonna have it investigated

[tjbrookes2004]

Hi again , my rear heater is working fine but the front still blows cold.
I've ordered the tm1 combi from haydn as I'm still worried about temp , do you think its an air lock

[g8dhe]

Have you checked the actuation of the heat flap in the passenger foot well ?

Have you checked the temperature of the coolant pipes feeding the front heating matrix ?

[tjbrookes2004]

Thanks Geoff, I'll have a look

[Winniebongo]

Your coolant may be full of Radweld or similar if someone has used this in the past to seal small leaks. It does this very well but ultimately causes problems as it can block small mater galleries, mixing with bit of rust and crud that accumulate in the system.
I the short term I would try to fix the heater alone if that is possible. The issue you have is not that unusual and I am sure there are other threads on here explaining what others have done, I haven't done this myself, we still have a working heater but if you want heat, it kind of needs to be on the highest setting.
In the longer term I would advise getting the coolant drained and flushed and filled with new coolant but being a Bongo the bleeding procedure is quite different to most vehicles, I can't stress enough, be careful who you get to do it, best if you can find someone who has real experience of the vehicle. I am saying this as our experience was that we had several years of trouble free motoring, then we had over-heating. I thought we had caught it early enough not to do any damage but after changing virtually everything in the system and several bleeding attempts, I had to call time and send it to a Garage who diagnosed (eventually) a cracked head. To be honest I think we are still suffering from the fall-out of all this but it is officially "fixed" although there have been loads of ancilliary problems need I say more

[MightyBongo]

TJ out of interest, did you get a result from your investigations into your heater issues? I have similar issues currently with a leak who's origins are unknown. When I started investigating my Bongo's coolant system I found no heat from heater and its without a thermostat, then once the thermostat was fitted and while bleeding system, we managed to break the plastic connection from the front heater matrix. (Over enthusiastic pipe squeezing).
I'm currently investigating a leak and now considering whether Mr Rad-weld has been upto no good as it appears that at some point a new radiator has been fitted along with a new head.

Also has anyone had any experience of purchasing off ebay a copper and brass front heater matrix?
https://www.ebay.co.uk/itm/Mazda-Bongo- ... 3875552314

Looks a more suitable alternative at £95 from the midlands. We're going to try refitting the hose to the last half inch left hanging out the bulk head for now to see if we can locate the original leak.

Thanks in advance of your replies and advice.