Radiator overheating

[stefanovic]

My water tank was low so I topped it up this morning for my wife to visit her parents. I didn't add coolant which I guess I should have done. One hour later she had to pull in a lay-bye as the vehicle started making strange loud noises. She opened the bonnet and the engine had overheated and the water tank was empty. A mechanic happened to pass by and filled the tank with water and added some coolant and when she started it up all the water boiled-up and overheated again. She managed to get it to her parents house once the vehicle had cooled down and is now waiting for the mechanic to come and have a look, which will most likely be after 5pm tonight or tomorrow morning. Can any forum members offer any suggestions on what the problem may be on an otherwise fine working Bongo 2.5 diesel? What guidance could I offer the mechanic, if any.

Thanks

[francophile1947]

How low was the level in the tank before you topped it up? You may have got air in the system and it needs bleeding properly (see fact sheet in Member's Area).
Otherwise, it sounds like a head gasket or cylinder head gone

[stefanovic]

How low was the level in the tank before you topped it up? You may have got air in the system and it needs bleeding properly (see fact sheet in Member's Area).
Otherwise, it sounds like a head gasket or cylinder head gone

It was very low surprisingly.

[francophile1947]

With any luck, you've just drawn air into the system. Bleeding the Bongo cooling system is more difficult than most, so make sure your mechanic knows what's involved.
First though, where did you lose the coolant from? It's clear there must be a leak and it's no use doing the bleeding until you've found, and fixed, it.
It's well worth fitting a low coolant alarm, available from member Haydn Callow - your low coolant would probably have triggered this before air was drawn in.

[haydn callow]

Apart from coolant bubbling in the tank....how do you know you overheated ?? did the temp gauge go to HOT >>
Sounds as though you may have a bigger problem than just air in the system....whatever you do make sure the garage that looks at your Bongo knows about the Bongo cooling system...it is unlike most and needs to be understood.
Download the coolant bleeding factsheet and hand it to the garage,

[stefanovic]

Thanks for the advice so far.

The local mechanic fears the worse though he doesn't know the Bongo.

Is their a list of Bongo friendly garages available?

If it's a head gasket do you have any idea what it may cost to replace?

[Harry]

There is a list of Bongo friendly garages in the members only area of the main site.

Cylinder head gasket will cost around £500 inc parts but make sure the head is pressure tested and skimmed whilst it is off. You may also require a new set of cylinder head bolts.

New cylinder head fitting will cost between £1500 and £1800

I'm in the process of scrapping my van as beyond economical repair because my cylinder head is badly cracked.

Good luck

H

[Peg leg Pete]

My engine overheated several times until I sorted out the airlock, no damage to the gasket as I stopped as soon as it started to bubble up into the expansion tank, never fitted a low coolant alarm, never felt the need to just kept an eye on the level of the coolant etc, your choice of course. our bongo as run fine for two years since the overheating

[The Great Pretender]

Harry where are the cracks, are they around the exhaust valve area?

[Harry]

Spot on TGP

On one of the middle cylinders

H

[stefanovic]

The AA guy came this morning and said he thinks it's an airlock due to the fact that the top radiator hose is hot and the lower one cold. He tried to bleed the coolant guided by a print out from the members area but got stuck when he found a long time disconnected hose underneath the passenger seat which he thought was the air bleed hose. He is confident that it's not the cylinder head. Any advice for my local garage on how to proceed with removing the trapped air? I have booked it in for tomorrow.

Cheers to everyone for your comments so far.

[missfixit70]

When you say a long time disconnected hose, what exactly do you mean? can you see where it's disconnected from? Can it, or a new one be refitted? The bleed hose is a long hose that comes out of a pipe on the thermostat housing on the side of the engine, & it usuall bends back on itself wher it's clipped to the bodywork, without that, bleeding it ain't going to be easy, if at all possible, you may be able to do it with a vacuum system.

[stefanovic]

Hi Kirsty, thanks for your response. I don't know who disconnected the hose and when. The AA mechanic told me it's the air bleed hose. I can say that it's a black hose about a meter and a half long (a guess) with clips either side. It's located under the passenger seat. Why would they have disconnected it?

My bongo overheated two years ago and the mechanic said at the time that the problem was connected to the heater system. I had lost my front heater and he later fixed it but it was a bit of a bodge allowing me to only use it on setting number 4.

[missfixit70]

I hope you're not still using this guy, cos it sounds like he's talking excrement. Sounds like you had a problem with your heater fan resistor & he's bypassed it so the fan only runs on full? This would not have been anything to do with an overheating issue & can be repaired or replaced easily if you check the factsheets in the members area - of course it depends what he's done to it
I have no idea why he would have disconnected the bleed hose, he obvioulsy doesn't know bongos, there is a list of bongo friendly garages in the members area which may be of use.

[francophile1947]

The AA guy came this morning and said he thinks it's an airlock due to the fact that the top radiator hose is hot and the lower one cold. He tried to bleed the coolant guided by a print out from the members area but got stuck when he found a long time disconnected hose underneath the passenger seat which he thought was the air bleed hose. He is confident that it's not the cylinder head. Any advice for my local garage on how to proceed with removing the trapped air? I have booked it in for tomorrow.

Cheers to everyone for your comments so far.

I don't understand that If it was disconnected, why would it still be there? He wasn't expecting it to be connected at both ends was he?
It takes a long time to get the bottom hose hot, but the system won't fully bleed until it is - it only gets hot after the thermostat opens, which is not all that often in normal use at this time of year.