Water coming out of rear overflow/expansion?

[sdemmery]

Hi Everyone,

I don't often post as a quick search almost always finds what I need & I never seem to have anythng usefull to say thats not already been said Anyway still have my Bongo after 4 years & still think its the best vehicle ever. But i have a problem....

About 4 months ago I had a front heater matrix go, I replaced it & follow the funnel bleed method to refill the coolant it was a pain to do but all has been fine until yesterday (done about 3000 miles). I had the front heater on full & the blower on for about 15mins, I started to smell the dreaded foul water smell. Checked the front matrix & no problem. However there was a pool of hot water midway under the van (drivers side). Looks like it was coming out of an overflow pipe for the rear heater. Any thoughts on why this might be?

When I last checked water (about 2 months ago, yes I know ) I filled the front expansion up to full, it wasn't that empty but I guessed if I fill it up it can always expand out at the front. But as I say i'm concerned about losing coolant from the rear 2 months after the last fill.

Any thoughts would be much appreciated.

Cheers
Stuart

[waycar8]

Loing coolant from the rear???

There isnt a overflow pipe for the rear , there one on the expansion bottle and thats it , check all your hoses one might be leaking or if you think you have an overflow pipe at the rear then a hose has come off

[sdemmery]

Bit of an update. After topping up the water (it took 4ltrs!) I carefully drove to work (10min drive) about 100yrds from destination temp gauge had moved to 2 o'clock position (normally sits around 11) fans had cut in, smelly water & a puddle. Needless to say its now parked, im parinoid about cooking the engine.

What I did notice was that the heater was blowing cold air the whole time, turning the rear heater on had no effect & on closer inspection it seems the 2 pipes near the rear over flow are also dripping. A hole in both pipes seems unlikely I guess? Is this a pressure thing? Something getting so hot the water is trying to push out of the pipes around the clips?

Any advice would be appreciated, Ive been having a nightmare time with my wifes car for the last few months this is the last thing I could do with.

Cheers

Stuart

[sdemmery]

Hi Waycar,

thanks for the quick post back Im desperate to get this sorted, believe it or not I have to drive 7 realives to a funeral on Friday. I get all the fun jobs

I can see 2 pipes about 20mm in diameter attached to a tank & then about 10 cms towards the front of the car an outlet (with no pipe on) about 10mm diameter. water is dripping from there & the 2 larger pipes where they attached to the tank. Car is in the carpark but I will try to get a picture later.

Stuart

[waycar8]

Stuart, its not uncommon for the rear heater matrix pipes to corrode only real way to check is take off the hoses and look at the pipes them selfs, But you have got air in the sytem without a doubt so a good bleed is needed...........4l is a lot to top up if the water line in the expansion tank drops below the minimun mark then it will draw air into the system.

I would check to make sure the pipes arnt corroded by dropping the coolant and taking off the hoses, then refill and bleed it.

[wonkanoby]

as a temporary you can just take the rear heater out of it

bodge the 2 pipes together to complete the circuit

then as said rebleed it all

[dunslair]

Sounds like the rear heater matrix has failed. The coolant would fill up in the tank / housing and come out of the drain hole or drip from around the entry point where the hoses go in. If you do not need the rear heating , simply bypass it at least for now, and do a coolant flush and change to keep you on the road. (we just had same problem, post ran a few days ago '2L coolant loss')

[sdemmery]

You guys are tops! thanks for the quick replies, i love this forum

I had suspected the rear heater matrix, Im an expert at heater matricies having done the front one (not really the bongo cooling system is still a mystery to me). I think as suggested I will bypass it to get me through the week, see if that helps. Its a pain in the rear losing coolant as I have to buy yet more antifreeze, had we have been in the summer I wouldn't have worried temporarily. I will post back here to let you know the outcome.

Cheers & thanks again for your help
Stuart

[karena]

Sorry to chip in with a dumb question.Is it possible that by-passing the rear heater matrix radiator you could increase pressure on the front one - i ask because within a week of having by passed ours, the front radiator started leaking.
We are replacing the front ASAP, but were going to leave the rear one until we get better weather and physical help, but i dont want to blow another if thats what the cause was.

[waycar8]

Sorry to chip in with a dumb question.Is it possible that by-passing the rear heater matrix radiator you could increase pressure on the front one - i ask because within a week of having by passed ours, the front radiator started leaking.
We are replacing the front ASAP, but were going to leave the rear one until we get better weather and physical help, but i dont want to blow another if thats what the cause was.

Hi Karen, if you have by passed the rear one then (if it was blocked or leaking) wouldnt cause the front one or the rad to fail, the presure will be the same with or without the heater matrix in place if your front rad is leaking then I would get a replacement, the seal around the top where the seam is inbetween the core and the plastic top generally goes due to age ect.

[missfixit70]

Sorry to chip in with a dumb question.Is it possible that by-passing the rear heater matrix radiator you could increase pressure on the front one - i ask because within a week of having by passed ours, the front radiator started leaking.
We are replacing the front ASAP, but were going to leave the rear one until we get better weather and physical help, but i dont want to blow another if thats what the cause was.

I don't think so, I suspect yours had already been subject to severe temps (possible low antifreeze concentration?).
Some bongo's come without a rear matrix at all.
By bypassing it (rather than removing that element of the cooling loop completely, as I think it would be with no heater fitted as standard ), you're actually probably reducing the system pressure.

[haydn callow]

Please .... make sure you bleed it properly after fixing...

[sdemmery]

Hi Haydn

Just reading the section you wrote for the coolant fact sheet. Can you tell me when I am doing the rev cycle & ensuring the funnel level does not drop should the expansion cap be on or off? You say replace the rad cap but dont mention the expansion. I did it without the expansion cap on last time & coolant was flowing out of the expansion at a fair rate. Is this right?

Cheers
Stuart

[haydn callow]

Tank cap off...you shouldn't get coolant overflowing from the tank unless you are overfilling the funnel....If you have a LCA fitted it will tell you every time the level gets a bit low...then raise the funnel

[sdemmery]

Thanks Haydn.

Yet another reason for me to get a coolant alarm. Your right last time I had the funnel to high for too much, I was doing more "seeing" than "sawing"

Anyway bypass fitted, all refiled & seems ok so far, will keep a very close eye on it over the next few days.

Thanks everyone for your help, as I said before this forum is great & perhaps the main reason I still have a bongo

Cheers
Stuart