Air bubbles in radiator

Pops_20

Hi All, not asking for myself but for a friend.

Do tiny air bubbles in the radiator mean a blown head gasket?

I tagged along to a viewing recently with a friend who is selling his car.

The potential buyers gave the car the once over, a quick spin, and then spent 10-15 minutes revving the car at 2-3k rpm with the radiator cap off (:eek:), and then promptly diagnosed the car as having a head gasket leak, with only a matter of time before it blows altogether, and then offered half the asking price.

Their reasoning was that there were tiny air bubbles in the coolant in the radiator, and that the coolant top hose went soft and then hard intermittently.

The car does not overheat, it actually runs cool most of the time, which we suspect is due to it having a larger radiator than factory (thicker core, aluminium unit).

There is no mayonnaise in the oil cap, and the dipstick doesn't show any signs of mixing with the coolant.

My friend had noticed a very small drop in coolant over time (half the reservoir capacity dropped over a month or so of constant driving), but other than that the car drives perfectly.

Does this sound like an imminent head gasket failure?

rex-x

Its possible, coolant level shouldnt really drop much ever, its going somewhere

biko

Bubbles in coolant doesn't automatically mean there is a headgasket that will blow soon. Particularly if they were revving car like mad.

But together with car losing coolant, particularly if there is white sweet smelling smoke on startup, I would say it is possible.

Does coolant look fresh and clear?

Pops_20

Coolant looks fresh and a good clear red/green colour as it should. It was completely flushed and refilled in October and the car has done about 3,000 miles since then and it still looks fresh.

There is a very small amount of crystallized coolant around the thermostat housing where both the coolant hoses attach to the engine, so maybe that is where it is leaking from, but very slowly.

My main concern really was that the potential buyers were revving it to create the symptoms of a problem in order to get money off. The car has been running cool from day one and never ever overheats, which I would expect it to do with a HG on the way out and 3,000 miles of driving.

biko

Yeah, I'd agree it was a possible way to get price down.
Try revving your own car the same way and see if bubbles start appearing