Overheated, low coolant, advice.

[Hippotastic]

Used me Bongo last week after a cold night, and it overheated after a few stop starts. As I was going on holiday, we parked it, and got a taxi to the airport.

Got back last night and put about a gallon of water in the header tank! I checked it a few weeks ago and it seemed fine to me, and its always ran properly too.

Today, I tackled the problem (?) by sort of following BigDaddyCain's method in the fact sheet area. In short, I opened the bleed pipe, pointed it at a bucket and removed the cap off the header tank. This allowed the water in the system to flow out, and I stood there for 15 minutes or so with a water hose filling the tank whilst it bled out the opened pipe. When the water was clear that was going into the bucket (it was a ruddy kind of rust colour), I started the engine, and continued to flush the system with both heaters on 32C and full blow. Did this for 10 minutes or so, then put the cap back on. This stopped the bleed pipe leaking, and I let the engine warm up.

Once warm, I took the cap off and let a few litres out the bleed into my bucket, then bunged the bleed pipe and added the same in Anti-Freeze into the header. I repeated this until all 5 litres were in, and I closed the cap and bunged the bleed pipe. The water started looking pink as soon as I added the anti freeze, but I kept what went into the bucket and put it back into the bottle once finished. I am keeping this for top ups after it all settles down.

So I ran on idle when finished and the temp gauge never moved. The engine had been running for over 40 minutes, so i went for a quick run around, and the gauge moved up to 11 o clock and stayed there. I still had both heaters on 32C and full blow (with the windows open, them heaters are fierce). I came back checked for the level and funny noises, went for another run, about 20 minutes, everything still seems okay.

I opened the bleed pipe and scorching hot water came out. Silly me, I raised the pipe up and it shut the flow off, and I re bunged it. I then removed the cap off the header tank and that bubled up and spilled out. So there is pressure and the water is hot as it should be. I will let it all cool down now and then go check the level in the header tank.

So apart from checking the levels and checking for funny noises, anything else I can do to keep on top of this? And have I missed anything important?

Ta.

[dandywarhol]

I think I'd be finding out where the original gallon of coolant went!

[Hippotastic]

Yes I was very suprised at how much I had to add. But there seems to be no leaks, and I just took it for a run and its running great. I guess I just need to keep the other eye on it.

[mikeonb4c]

Defo keep a close eye on it. I'd put it on 'Special Measures'. Have you got any of the coolant/temp alarms discussed on here fitted? Worth considering if not already done. Rusty coolant always makes me suspicious that there may be clogging in the system. A good backflush would be good and really, a flowtest of the radiator with a view to replacement if in doubt (do thermostat too for good measure).

Keep us posted & good luck

[Hippotastic]

ok the problem outed itself today.

I borrowed a picture I searched for as I have not taken any pictures.

It is here http://www.igmaynard.co.uk/bongo/forum/ ... de#p183437 and posted by The Great Pretender (thanks and I hope you do not mind me borrowing your image)

On my Bongo, the pipe with a join and blue flashing has decided to give up. It is perished on the top, and I found the leak today after noticing water under the van. I took the hose off and went to a local parts shop, and they cut the end off and added a new bit like the picture. At first they were "no you got to go to Mazda and get the part, we cant order it". Then after whining, they agreed to cut off the perished part and add the extended bit like the picture. I have fitted it back on, and will bleed the system in the morning.

I have a question. My pipe does not go right like the picture, it goes downward and towards the rear and joins a metal pipe next to the sill. It comes off the block, and then snakes down with about 4 bends in the pipe to join a metal stub that is a juntion to a forward/rearward metal pipe. It is around 18" in length. If I was to replace this part, under the drivers seat, would this be the pipe to do it?

http://cgi.ebay.co.uk/MAZDA-BONGO-SILIC ... QQihZ017QQ

The reason for asking as it is described as the pipe I need, but it sure does not look like mine on the Bongo.

Any thoughts? I might try to take picture tomorrow in the daylight if my hands are not too dirty.

[Hippotastic]

http://cgi.ebay.co.uk/MAZDA-BONGO-SILIC ... QQihZ017QQ

This looks closer to my pipe. But it is under the Drivers seat, not the passengers seat. Confused....

[Hippotastic]

http://www.bongobits.com/Main.asp?PageN ... roduct=240

Found it. Thanks to a posting by Simon Jones. Ta

[missfixit70]

The picture you chose to plagiarise is TGPs modified coolant system, hence the difference, he modified it to supply a fuel heater for a twin tank veg oil system. I'm quite surprised you managed to id your leaky hose from that
If you want to order a silicone hose rather than a standard rubber type one, just ask for the one that goes over the starter, Flippa'll know which one you mean, I think it's the second most common one to go after the bigger top hose just forward of that one.
Glad you found the source of the leak, but don't get too complacent, give the others a good check over, after all if one's gone, how long before the rest start going? I'm not trying to be a harbinger of doom, just don't want you getting caught out, if you haven't already, think about replacing all the hoses & maybe investing in a temp alarm such as the mason or the TM2, & dare I say it a coolant level alarm, which would have prevented you overheating in this case. Check your level as often as possible if not.

[Hippotastic]

The picture you chose to plagiarise is TGPs modified coolant system, hence the difference, he modified it to supply a fuel heater for a twin tank veg oil system. I'm quite surprised you managed to id your leaky hose from that

Ah then that is why it goes to a different place to mine. Well I managed as the place or origin is the same i guess, and I know what mine looks like now...

If you want to order a silicone hose rather than a standard rubber type one, just ask for the one that goes over the starter, Flippa'll know which one you mean, I think it's the second most common one to go after the bigger top hose just forward of that one.

I looked at his ebay site, and simply could not find what I needed. I was working under the confusion of looking at a modified system in that picture I searched up, but as I posted I found my pipe refered to by Simon on Bongobits. If it is indeed the second most common pipe to fail (i believe you) then I would have thougt it might be easier to find on Flippa's page? My bad I should ask next time.

Glad you found the source of the leak, but don't get too complacent, give the others a good check over, after all if one's gone, how long before the rest start going? I'm not trying to be a harbinger of doom, just don't want you getting caught out, if you haven't already, think about replacing all the hoses & maybe investing in a temp alarm such as the mason or the TM2, & dare I say it a coolant level alarm, which would have prevented you overheating in this case. Check your level as often as possible if not.

Oh I am learning not to be complacent with the vehicle. My faith is not broken, but after a flat battery and now loss of coolant, I am very much more aware. Its the costs of a full set of hoses and an alarm together this close the the big spend in the name of religeon thats on the real problem. I am now in the AA, carry jump leads, and fully intend to replace all the hoses in time. That is when I can afford that sort of outlay. I also have little in the way of tools for working on a car, so that cost has to be factored in too. I know that arguement that a new head costs more, but in that case I find it easier to get my head around doing it all in one go, by a garage that knows it stuff, with some confidence after that all "should" be well. One hose gone probably means another is due to go when the pressure is shifted, but I need the van this weekend, and will just have to cross my fingers the repair holds and the other pipes are okay.

[mikeonb4c]

If it were me, I would:

* Replace the dodgy hoses
* Undertake a risk assessment of the remaining hoses and only replace obviously brittle/swollen/dodgy ones
* Fit a low coolant alarm and let that advise me if/when something happens

That approach need not be too costly or labour intensive, but others may take a different view

[missfixit70]

I don't think you need to panic about it too much, Mikes approach is a good one, along with lots of visual checks & STOP if there is any sort of coolant/overheating issue. DO NOT "just get it home" (not that I think you would ). Whatever you do, don't let it spoil your enjoyment of the Bongo

[Hippotastic]

in my yoof I worked on cars, and now I have overcome my reluctance to get my hands dirty and lie on the floor (getting up again is the hard bit) I am quite enjoying poking around and having a looksee. I think the patched hose is doing its job, it got hot and I could see no further leakage. Both heaters are warm when on, and so far there has been an annoying little puddle when I have stopped today twice but I have lost nothing out of the expansion tank. I guess it might be left over puddles from the spils during fill ups that have worked its way to the belly pan and is finding its way out.

I took the air box off under the bonnet and looked at the hoses around the radiator, I checked both sides of the engine and all the other hoses I can see seem okay. I removed the belly pan to have a look where this little puddle was appearing from and all seems well, but then I aint really sure whats what. So I think I am on top of it, just got to keep checking the level in the expansion tank.

Question - When you unbung the bleed pipe, and the cap is still on the expansion tank, should there be any fluid coming out? I think not, and assumed this is correct, but when flushing yesterday I found you can stop the flow by putting the cap back on then putting the bung in if you are on your own rather than dash about.

[Hippotastic]

Ok ran the Bongo all weekend, and it ran fine. I ran it down the motorway to central London all well. The little puddle did not appear the next morning when I was parked in a garage. I ran it across London for a few hours and its was good as gold. Then I ran it home on the motorway again, not a problem.

I got a new replacement pipe now, and I might put it on rather than keep the repaired one. It seems to be holding its coolant now, so I will decide a the weekend if I want to do the work again. Should not take long this time, but I am a little confused with the bleeding procedure. I have read the fact sheets, and I am not entirely sure of when its done or not. I might do the funnel in the bleed pipe see saw method next.

[bigdaddycain]

Hi Hippotastic, it sounds like the bleeding was done fine in your initial post, right up until you said you raised the bleedhose up to stop the flow of water!

Not only does that stop the water from flowing, the coolant will make it's way back down the bleedhose, till it reaches the cylinder head, then lo & behold! An airlock in the head!

I think all the bleeding methods work, (otherwise they wouldn't still be on here), which method you use is down to what makes most logical sense to you.

The principle of the hosepipe method is to minimise the chance of an airlock in the first place,via displacement, decanting, or whatever word you'd like to use to expel the unwanted air with the stream of water.

Just remember to check the level of coolant after the engine has cooled "post bleed" No method on here expels ALL the air, that can only occur naturally after the engine has cooled,the coolant level will be a litre or so lower the day after a bleed, upon cap removal for top up you will hear the air escape, that's what would have been in the head the day before. The level has dropped via displacement of the air in the head.

[dandywarhol]

So in that case Ste, does the manual show the bleedpipe HIGHER than the head and expansion tank?

The pic shows the bleeder pipe hanging from the steering wheel spoke - to get the pipe to the highest point. That way ALL the air is forced out IMO.