Smoke and coolant

[dovestar]

Hi All,

My wife's in a bit of a panic because the Bongo has started smoking just when she quit! After about 15minutes of driving smoke starts appearing from the bonnet which is not somewhere I'd expect to see it coming from even in the worst of situations.

I checked it over last night and found the oil was a little low but not drastically and the engine running smooth as anything so no worries there. The only thing of concern was that the coolant level was hovering at minimum when I'd just topped it up to max last week, although this is a problem, I can't see it causing smoke.

Does anyone have any ideas?

[Veg_Ian]

If it's coming from under the bonnet then I'm guessing steam not smoke and the coolant level dropping would confirm that. After 15 mins, the coolant system will be hot and pressurised and probably chucking out steam and coolant from a small leak. This may only manifest itself when hot and under pressure making it difficult to find. Have a good look under the bonnet at the hoses going into and out of the rad, the rad itself (core and frame), the expansion bottle and its hose. If you are running with an antifreeze mix (as you should be) you should be able to pick up tell tale signs of blue/white staining around the leaking area.

[dovestar]

Thanks Veg_Ian, that's a reassuring response; I can handle a coolant leak. I'll have a good look around for the staining and let you all know how I get on.

Dovestar

[scanner]

Yes you need to know whether it is smoke OR steam.

Not anything like the same thing and nothing like the same causes.

[Veg_Ian]

You should also be able to smell the difference. With the engine being mid mounted there isn't much to smoke under the bonnet apart from an electrical fault and I'm guessing you would have known about it in other ways if that were the case..............

[missfixit70]

Could it just be the pressure cap not sealing/working properly?

[dovestar]

The problems did seem to start after I initially topped up the coolant a week ago. The pressure cap hadn't been opened for the two years prior to that so I guess that could be the problem. However, something tells me that would be too easy!

My main problem at the moment is that I'm only going from what I've been told of the symptoms, I've not actually seen this smoke/steam/whatever myself. I'll give it a good run tonight so I can see for myself.

[missfixit70]

The problems did seem to start after I initially topped up the coolant a week ago. The pressure cap hadn't been opened for the two years prior to that so I guess that could be the problem. However, something tells me that would be too easy !
My main problem at the moment is that I'm only going from what I've been told of the symptoms, I've not actually seen this smoke/steam/whatever myself. I'll give it a good run tonight so I can see for myself.

Not necessarily, check the things you've played with first, first rule of fault finding

[scanner]

The problems did seem to start after I initially topped up the coolant a week ago. The pressure cap hadn't been opened for the two years prior to that so I guess that could be the problem. However, something tells me that would be too easy !
My main problem at the moment is that I'm only going from what I've been told of the symptoms, I've not actually seen this smoke/steam/whatever myself. I'll give it a good run tonight so I can see for myself.

Not necessarily, check the things you've played with first, first rule of fault finding

Yes.
When you topped up did you overfill slightly? and the surplus is now being ejected?

Why did you have to top up after so long without having to?

[dovestar]

It certainly wasn't over-filled. I had to top it up because when I checked it, it was low. I check all the levels every few months (I know I should more often), this was the first time in two years that I found it was low. This is why I suspect the problem isn't the cap I opened but that the leak came first.

[haydn callow]

How LOW was low ...when you topped it up ???

[dovestar]

A few mm off the low mark in the expansion tank.

[haydn callow]

No harm there then.

[dovestar]

Coolant leaking out all the way along where the core joins the top of the radiator. Will be calling Bongo Fury telephone order line in the morning for a new radiator!

[mikeonb4c]

And fit a low coolant alarm