Antifreeze boiling over and Engine overheating - Please help

[samuel]

Had the same problem. And i thought i had sufficient anti-freeze on board. On the school run the engine temperature just shot up, pulled over immediately and switched the engine off. It occured to me immedialtely that i had suffered an ice block due to freezing coolant. Topped up tank and got home where i drained the system and filled with new anti-freeze.

It is so important though to get the system bled properly. Both heaters need to be open on High and don't forget that when they are done the air conditioning is switched on as well to get the air out of the air con radiator.

All seems well now A lucky escape me thinks and hopefully this all you have suffered.

Tim

[Aunt Trumpet]

If you don't get the stat open (bottom hose hot) you "could" have air trapped in the bottom of the rad and bottom hose....A ticking bomb.....take the fan fuse out whilst bleeding.

Fair point but I've sat on the drive for ages in decent warm weather trying to get it hot. I only managed it by taking it for a drive and putting the engine under more load, extremely difficult to achieve whilst static in my experience.

[missfixit70]

Heaters don't need to be on, the coolant flows through them all the time, whether they are on or not.
Turn them on to check they are getting warm, then turn them off again, or it'll take forever (if at all) to get the system hot as it's just sucking the heat out via the two heater matrixes.
Turning the heaters on just directs the air over the matrixes at whatever speed the fans are blowing mixing cold air with the hot to get desired cabin temperature.

[mikexgough]

Heaters don't need to be on, the coolant flows through them all the time, whether they are on or not.
Turn them on to check they are getting warm, then turn them off again, or it'll take forever (if at all) to get the system hot as it's just sucking the heat out via the two heater matrixes.
Turning the heaters on just directs the air over the matrixes at whatever speed the fans are blowing mixing cold air with the hot to get desired cabin temperature.

and make sure the heaters are really hot before moving on to the bleed process.......... my bottom hose doesn't get hot just warm, just how it should after passing through the radiator......my Rad Fans rarely run (other than with air con)...but that is another topic for another day.....

You have to be patient when bleeding a Bongo.........I usually consume a brew or two...

[haydn callow]

the air conditioning is switched on as well to get the air out of the air con radiator.

How does that work then ?


Agree with Kirsty about switching the heaters off once warm air comes out.

[missfixit70]

the air conditioning is switched on as well to get the air out of the air con radiator.

How does that work then ?


Agree with Kirsty about switching the heaters off once warm air comes out.

In this weather( ie around zero degrees & below) I reckon it's going to be virtually impossible to get the system up to temp if you have the heaters on during the warm up process, it'll be sucking the heat out as quick as it goes in IMO.
I also reckon you'll struggle to get it hot on the bottom hose with out taking it for a run when you're bleeding, but I ain't going to go & try it to prove it
maybe worth having a heater helping it along underneath? (bear in mind any elf & safety implications if using electrickery when there's water splashing about - common sense & all that)

[mikexgough]

I only have the flaps open set to hot but no fans blowing across them............force of habit from other cars I have owned that have valves for the heater matrix....

......and it obviously will take a wee while longer to get hot with the current ambient temperatures.....took mine long enough when the ambient temp was 32C in July here.........

as for Aircon.......another separate circuit....

[haydn callow]

Bled one yesterday.... -3C outside where we were...took the fan fuse out and it took 40 mins......about the same as normal.
Went out in ours, and a trip that normally gets the temp on the TM-2 up to 90C ...we only managed to get up to 82/83C

[missfixit70]

Bled one yesterday.... -3C outside where we were...took the fan fuse out and it took 40 mins......about the same as normal.
Went out in ours, and a trip that normally gets the temp on the TM-2 up to 90C ...we only managed to get up to 82/83C

Can't argue with that

[PisceanJoy]

To Ipswich Guy - I used to live there and used to use Deben Vechicles off Bramford Road Didn't have a Bongo then but they were always very helpful and reasonable priced

If you took the instructions from here i'm sure they would be able to sort it

[mikexgough]

..took the fan fuse out

I just turn them off....

[haydn callow]

Radiator fans ??

[mikexgough]

Radiator fans ??

Haydn, sorry I didn't twig, as I said in a previous post on the thread......my Rad Fans, like quite a few other owners who have indicated the same on the recent Cooling System Thread, rarely run.....even in the summer....they never did when I bled my system last summer after I changed my Radiator (when the plastic/metal came apart as they do with age) and all the air was out of the system....
Obviously if a Bongo runs it's fans reasonably frequently then indeed you might feel the need to "kill" the fans from operating when bleeding the system.
Now some folks may read from this that there could be/is an issue with their Bongo but, I am not a scaremonger and no one should be in a state of fear just because other folks Bongo's rad fans rarely run, but their own Bongo's fans cut in and out more frequently - (Obviously this will happen as a matter of course with the A/C switch on but that is a different subject)

Hence the current work to find out how the ECU's work and when & how the fans are programmed to switch on...to link in with the Cooling System thread to provide the techie people as well as the not so techie with a "dummies" guide as to how the complete cooling system works...not just the water based side of things

[mikeonb4c]

Went out in ours, and a trip that normally gets the temp on the TM-2 up to 90C ...we only managed to get up to 82/83C

But if the sensor is surface mounted could the lower figure be due to increased surface cooling at v. lower air temps and the engine core temp might not be much different from normal. In theory, good engine design would aim to keep engine core temp steady over a range of outdoor temperatures.

[eoptio]

Hi

ref the aircon being on for bleeding the coolant, is this required and if so why? Just changed radiator/hoses/coolant on on ours a few weeks ago (before the snow...) not seen instructions on having to switch on the aircon for bleeding?

K