Mysterious coolant loss.

[Andy H]

On mine there was a hairline crack right on top of the radiator plastic side tank.When under pressure it fired a fine spray straight at the underside of the plastic thing that runs across the top of the radiator.Took me ages to spot that!

I had exactly the same thing on my first Omega.

I have had the plastic tank split after entering a car park and bumping the spoiler on a ramp that was steeper than it looked

The other sources of leaks that haven't been mentioned yet are corrosion of the ally plate that the oil cooler lives under, the coolant transfer pipe, the core plugs at the back of the heads and (finally) the head gaskets........

[Bigron]

Thanks for all of your suggestions, gents; I will follow them up closely tomorrow.
A slight aside: in previous posts, there was mention of a way of eliminating/confirming the HBV from suspicion, but I can't find it. Is it heater on Hi or Lo to stop a leak?

Ron.

[Doctor Gollum]

Thanks for all of your suggestions, gents; I will follow them up closely tomorrow.
A slight aside: in previous posts, there was mention of a way of eliminating/confirming the HBV from suspicion, but I can't find it. Is it heater on Hi or Lo to stop a leak?

Ron.

Both. Depends where it's cracked

[Pmacca2000]

Maybe Thermostat housing ?
The first I knew was a coolent warning, turned out half the coolant was in the middle of the V6 between the heads.

[TheBoy]

250ml per 50m is probably approaching point it should become quite easy to locate.

I've had to replace rads in both my Omegas in last 9 months, both had hairline fractures on the hot side of the rad. MV6 was right at very top, TBE was just below top temp sensor.

[BazaJT]

Must admit once I'd found the leak I "repaired"mine.Keyed up the top of the tank with some wet and dry,cut a small piece of plastic from a "loyalty"card that Maureen used to have keyed that in same way and stuck the two together with two pack epoxy.

[Lizzie Zoom]

Must admit once I'd found the leak I "repaired"mine.Keyed up the top of the tank with some wet and dry,cut a small piece of plastic from a "loyalty"card that Maureen used to have keyed that in same way and stuck the two together with two pack epoxy.

Blimey, I bet that was a right poxy repair!

Sorry, couldn't resist

[Bigron]

Lizzie, your "joikes" are worse than mine!
Anyway, I have found my leak and it's just where some of you have said - at the top nearside of the radiator. As a quick bodge this morning I used some 2-part superglue from Poundland; sprayed the aerosol part onto the cracked area and squeezed the gel part over it. It bubbled and hardened, and I drove off after about 10 minutes!
Ok, having read Baza's repair method, I will upgrade mine in similar fashion and cross my fingers..... 

Ron.

[Doctor Gollum]

A word of caution... it will eventually fail as such substances are heat sensitive

[STEMO]

A word of caution... it will eventually fail as such substances are heat sensitive

Everything will eventually fail 

[Bigron]

Ain't dat de troof, STEMO! 

Ron.

[Doctor Gollum]

A word of caution... it will eventually fail as such substances are heat sensitive

Everything will eventually fail 

Except death and taxes

[Sir Tigger KC]

If you've located the crack, you could try a 'plastic weld' by melting the plastic back together with a soldering iron or hot screwdriver. 

[Nick W]

Modern aluminium radiators with plastic tanks are consumables. When a new one is about £60, is it really worth trying to patch one up?

[Bigron]

Nick, on MY pension - yes! Iwould also have to pay someone (Serek) to fit it for me, so not just £60.....

Ron.