White residue on rad cap

[MudSurfer]

Hi all

Took the rad cap off tonight in preparation for coolant replacement and new stat, and there was some white residue on it, that looks and feels like limescale - there were a few blobs of it on the top of the outlet too - is it limescale or something more serious????

[dave.j.robbo]

Could well be limescale, I suppose. Need to use softer water when you refill in future!!

If it was a mixture of oil and water, the white goo would be more like mayonaisse than limescale.

[laser_jock99]

.... there was some white residue on it.... is it something more serious????

Yes- your car's got secret cocain habit!

[MudSurfer]

That would explain why it's taking so much money off me.......

[joker??]

That would explain why it's taking so much money off me.......

ask frank !!!

[kitesurf_phil]

I used antifreeze and distilled water in mine. No lurgies yet.

[sledge]

try your dip stick see if thats got the same cream on it!

[AuldNick]

It's dead, oil + water = cheese! Burn & claim doomed DOOMED.....or mibbi it's nowt

[Taliesins]

Hi all

Took the rad cap off tonight in preparation for coolant replacement and new stat, and there was some white residue on it, that looks and feels like limescale - there were a few blobs of it on the top of the outlet too - is it limescale or something more serious????

sounds like dried coolant to me mine has the same

[MudSurfer]

its got a kind of gritty consistency - which is why I think its scale, rather than emulsified oil/water - dip stick is oil only, oil filler cap doesn't have any goo on it either..

[M35A2]

Nothing to worry about mate. This happens on all the trucks I've ever owned. I think its where the coolant seeps out slightly then dries on the very hot metal. It usually happens around the rad cap and on the edges of the rubber hoses where coolant has seeped out.

DONT use tap water to fill the system. You can use a hose and tap water to flush system thru, but buy distilled water to fill the system. This should stop the limescale.