coolant leak - or not

[Sandy]

I say I have a coolant leak. Well, I know I have - if I don't top it up regularly, I overheat. But my mechanic has pressure tested it twice now, and swears that he can find no sign of a leak. Yesterday, as I reversed out of my driveway, I left a nice water trail on the tarmac, which stopped as soon as I drove off. I tried to repeat this this morning, but no leak this time.
Am I going mad? Is my mechanic?
Can losing coolant be a consequence of overheating, rather than a cause?

[missfixit70]

If you have to top it up at all you have a leak. Stop driving it until you at least have a Coolant alarm fitted or it's going to cost you up to £1800 if you kill the head, which you will if it "keeps overheating", is it being bled as per the factsheets in the members area?
Get in touch with Haydn Callow on here & get some leak detector dye & a uv light, could be a pinhole on a hose or pipe somewhere or the waterpump, which can be a bugger to see.
It could be that your head gasket is on it's way, especially if it has been overheating, do an exhaust gas sniffer test on the coolant header tank.

[bigdaddycain]

You may have a leaking water pump...They tend to leak when cold. (i assumed the bongo was cold when you said you were pulling off the driveway). The water trail isn't to be confused with the water that can settle overnight in the tray below the engine...or the water that escapes with the aircon switched on.

[Sandy]

Very many thanks. My garage did an exhaust test a couple of months ago and everything was apparently OK, but I still have a wee suspicion about the head gasket.
That's interesting about the pump leaking when cold.
How I wish I was a mrfiixit!

[Sandy]

Right then - I have now (after a long delay while waiting for a UV light from China!) completed the final search for a coolant leak - using Haydn Callow's dye. Zilch. Nada. And I'm still losing coolant. So it must be getting into the cylinders, right? So can someone please tell me what should be my next step (bearing in mind that I am not a very techie person - I just need to know what to instruct my mechanic to do.

[haydn callow]

What you need is a GOOD BONGO GARAGE and from your location that may not be easy...It is vital though that whoever gets involved they know Bongos inside out

[Doone]

One of our members (bongalong), had a similar problem - the coolant was evaporating, so he couldn't see it where the leak was. (I don't know, but I'm assuming that leak detector dye might evaporate with the coolant? Haydn will know.) Bongalong's post about the leak is here.
Also, another member (Malcolm Whittington) had a leak from a hose under the drivers seat, behind the fan - it's a tricky one to see as it drips onto the engine tray, but it's worth checking if you haven't already. His post is here.
Also, if you park on a slope, leaks can sometimes show up when you park one way round but not the other (downhill/uphill).

[haydn callow]

The Dye will stain the area it escapes from...however fine a mist

[mikeonb4c]

The Dye will stain the area it escapes from...however fine a mist

I don't suppose it would survive the combustion chambers and leave telltale signs in the exhaust pipe would it? Worth checking just in case.

If its already had overheating episodes, you have to suspect possible head/gasket damage, and there are various tests that can be done (and any good garage should know them).

Keep in touch and keep us posted - and Good Luck. It will be interesting to get to the bottom of this one and lets hope its not too bad

[Doone]

I say I have a coolant leak. Well, I know I have - if I don't top it up regularly, I overheat.

How many times has it overheated?

The Dye will stain the area it escapes from...however fine a mist

Thanks Haydn.
I think it would be worthwhile looking in the places mentioned in the links above, especially as one of the leaks discussed is in a place where it's hard to see the hose, let alone a leak, and it dripped onto the engine tray.

[Sandy]

Thanks y'all. I am absolutely certain I don't have a leak (after two pressure testings plus Haydn's dye test) and that the problem lies with the head/gasket. I will press on with tests in that area.

[Sandy]

Well, all sad stories come to some sort of end. Just to wrap this one up, Having eliminated all other possibilities, I ended up buying a new cylinder head (£621 from Autohead Recon in Inverness) and had it fitted by my local garage (£764) - total cost £1385 plus the earlier garage bills for checking for leaks in the hoses etc.
All I can say now is - IT HAD BETTER BLOODY WORK!
Thanks for all advice - scanning down the list of Forum topics, us Bongo owners do seem to have recurring problems with overheating, don't we? (Wonder what VWs are like . . . .?)

[mikeonb4c]

Well, all sad stories come to some sort of end. Just to wrap this one up, Having eliminated all other possibilities, I ended up buying a new cylinder head (£621 from Autohead Recon in Inverness) and had it fitted by my local garage (£764) - total cost £1385 plus the earlier garage bills for checking for leaks in the hoses etc.
All I can say now is - IT HAD BETTER BLOODY WORK!
Thanks for all advice - scanning down the l;ist of Forum topics, us Bongo owners do seem to have recurring problems with overheating, don't we? (Wonder what VWs are like . . . .?)

Glad it is fixed and hope it stays so. Have you fitted a low coolant alarm - strongly recommend it if not so the next leak is spotted before overheating occurs. You only see the problems on here but many Bongos (including mine) are in service and proving highly reliable, though they don't like being 'cooked'. My brother has just bought a VW Westy in Canada and it overheated on their first outing simply - as far as I can tell - because it was asked to sit in traffic. Good luck with the Bongo and hope you are now able to enjoy the best of this great design.

[bikemunky]

I couldn't find a hole either, however there was a tiny hole on my inlet manifold pipe (apparently?), and that was enough. You have been lucky so far, mine kept overheating when the pipe was fixed so suspected a blown head gasket. Exhaust gas in the coolant confirmed the same. I coudn't afford the repair so I bought some Steel Seal (kill or cure!). This is a clear, yellow liquid that you mix with the anti-freeze, which, according to the blurb, guarantees to seal blown headgaskets, warped heads, cracked blocks etc PERMANENTLY!!! Tuff talking I thought, but at 33quid a bottle worth a punt I thought. It was that or the scrap yard so there you go.

I read the testimonials on the stuff, and managed to speak to a guy from Yorkshire who had done 4000 mile on the stuff!!! My Bongo doesnt do that milage in a year so I tried it.

600 miles later, no loss of water, no overheating. Result! How permanent the repair is I don't know, but, if you haven't the cash for a strip down and rebuild, it is worth a go.

The stuff contains no particules to block or gunge anything up, and once repaired, the remaining stuf becomes inert and dissapears in the coolant. How I don't know, but its worked for me. It doesn't work on hoses though... Stick Steel Seal in ur browser and check it out.

Good luck!