Bongo Fury

Hi All
my v6 has started to blow the coolant out of the header tank,the problem started two months ago on a very hot day in cornwall, stopped for fuel coolant running out under the front passenger side of the van, rac man came did a pressure test, no leaks, topped it back up bled it and off we went, back home had it serviced and a good check of the cooling system revealed no problems, then heading down to the Looe bash on Thursday it did the same thing again but only while the engine was switched off, topped it back up and carried on all the way to buckfastliegh where the coolant alarm went off,coolant gone again, but his time you could see coolant all around the leisure battery tray and steam coming from the overflow hose on the header tank, no steam out of the exhaust so I figure not the head gaskets gone. the rac man came out and topped it back up and then followed me for a few miles he pulled me over as he could see the coolant steam coming out, the van is now being recovered back to contract mechanics to check out, the van will not be there until Tuesday, I was given a courtesy cay to get home in, that's a 500 mile 16 hour day !!!.
rgds Ian

What rotten luck.

redz79 wrote:Hi All
my v6 has started to blow the coolant out of the header tank,the problem started two months ago on a very hot day in cornwall, stopped for fuel coolant running out under the front passenger side of the van, rac man came did a pressure test, no leaks, topped it back up bled it and off we went, back home had it serviced and a good check of the cooling system revealed no problems, then heading down to the Looe bash on Thursday it did the same thing again but only while the engine was switched off, topped it back up and carried on all the way to buckfastliegh where the coolant alarm went off,coolant gone again, but his time you could see coolant all around the leisure battery tray and steam coming from the overflow hose on the header tank, no steam out of the exhaust so I figure not the head gaskets gone. the rac man came out and topped it back up and then followed me for a few miles he pulled me over as he could see the coolant steam coming out, the van is now being recovered back to contract mechanics to check out, the van will not be there until Tuesday, I was given a courtesy cay to get home in, that's a 500 mile 16 hour day !!!.
rgds Ian

Did they/you change the thermostat.

Hi
no thermostat change, the temp gauge has never been above half way until Thursday,top and bottom hoses on the rad are both warm and the heater is blowing hot, my thoughts are the rad maybe partialy blocked,rac man thinks water pump has lost a blade.contracts mechanics Simon is going to do a leak down test on each cylinder and work from there, the header tank cap disappeared a few moths ago, replaced with a 1.1bar cap.
rgds Ian

Hi,
Could try a basic thing like changing the expansion tank cap. Could be that's failing on occasions. Also check that the scavenger fan is working as the engine compartment temperature can get extremely hot when the vehicle isn't moving as there is no air flow over the block. And you do then have the heat being produced by the exhaust manifolds contributing. This may be just enough to push the temperature high enough to cause an issue, as especially as we have been having higher ambient temperatures of late. This is one reason why I have fitted a scavenger fan override switch, so I can switch it on if I think it necessary. The scavenger fan will run on after engine switch off if the engine bay temperature is high & then turn itself off as the temperature drops. The Stat for the fan is next to the hand break under centre consol. Quick way to test that the fan is free to run & not seized is to short the 2 wires together. It will run when you do this. You can check the thermostat by using a meter across the terminals reading in Ohms and then warm up the stat in water checking the temperature against Ohms. There is a section in the workshop manual on how to do this. It does sound as if the main state may be a possibility, or that the main electric fans aren't kicking in. Do you hear the fans running at all?

Cheers

Hi all
thanks for replies,the expansion cap went missing a couple of months ag0, I replaced it with one from a scrap bongo, the cap was marked up at 1.1bar, I like the sound of the scavenger fan override switch, my thoughts at the moment are to have the waterpump , thermostat and rad replaced, that's all the mechanical parts of the problem sorted, and a brand new cap on the expansion tank, in two years of ownership I've never seem the temp gauge above half way until last Thursday, luckily I fitted the low coolant alarm, it should arrive at contract mechanics garage tomorrow, I hope he finds the problem, my confidence in the bongo is dented at the moment, driving around listening for the coolant alarm is no fun.
rgds Ian

Out of interest, who did the bleed on the system and were they Bongo savvy? If not you could have an airlock.

Hi,

Bear in mind how expensive changing a water pump on a V6 is. Effectively its as much work as doing a cam belt change. If your going to consider doing it I would suggest that you should look at:- Cam belt change, cam belt tensioners replaced, oil seals on the overhead cams & oil seal on bottom pulley renewed. This would give all of the working parts on the front end of the engine a complete overhaul. Not cheap, but peace of mind for years to come.

Cheers

hi
the first rac man bled the system, no bubbles then, he works on plenty of bongos in cornwall , the cambelt was changed not long ago by the last owner, I think she would not have had the waterpump changed at the same time, when we first had the van we had the lpg serviced, they said the top rad hose had blown off while the van was ticking over, the van has now arrived at contract mechanics garage, simon will be on it tomorrow.
rgds Ian

redz79 wrote:hi
the first rac man bled the system, no bubbles then, he works on plenty of bongos in cornwall , the cambelt was changed not long ago by the last owner, I think she would not have had the waterpump changed at the same time, when we first had the van we had the lpg serviced, they said the top rad hose had blown off while the van was ticking over, the van has now arrived at contract mechanics garage, simon will be on it tomorrow.
rgds Ian

Good luck and keep us posted. V unusual for a v6 to behave like this

hi all
Simon has checked the cooling system out, pressured tested from the expansion tank the same way the rac man did I the first time it happened and no leaks, pressure tested from the rad cap backwards and coolant blew past the expansion tank cap, so it looks like the cap was the problem, also the expansion tank had a leak around the seem, this has been replace and a new mazda cap fitted, then he took it for a good long test drive including some motorway and all was fine, so fingers crossed.
rgds Ian

redz79 wrote:hi all
Simon has checked the cooling system out, pressured tested from the expansion tank the same way the rac man did I the first time it happened and no leaks, pressure tested from the rad cap backwards and coolant blew past the expansion tank cap, so it looks like the cap was the problem, also the expansion tank had a leak around the seem, this has been replace and a new mazda cap fitted, then he took it for a good long test drive including some motorway and all was fine, so fingers crossed.
rgds Ian

Excellent and lets hope that's an end to it. Fan over-ride switches are always a tempting addition regardless