2003 S60 Fluctuating coolant level. (New coolant reservoir cap) Topic is solved

[veenee]

Ha! So it was just the cap - good for you!

[jonesg]

There's no milky or discolored oil OR coolant. There's no white smoke coming from the tail pipe. It's not overheating.
I replaced the coolant reservoir cap and it isn't "boiling off" anymore. I still plan on replacing the radiator since it seems to have a small leak in the front right corner of the car.

That could still be the gasket if the problem moved from the cap to the radiator.

You can pull the overflow hose from the bottle at the rad, submerge hose in a bottle of water and watch bubbles from a cold start ,
if bubbles follow engine speed up and down it's the gasket.
Had the same problem on my old volvo, it blew the rad too.

Blown head gasket will not result in coolant in the oil , or oil in the coolant.
Combustion gas will overpressurize the cooling system.

[RickHaleParker]

I still plan on replacing the radiator since it seems to have a small leak in the front right corner of the car.

If it is just a small leak. I would JB Weld it. Works just as good as a replacement, lot less work and money.

My S90 had a small leak in the radiator core.

• Drained radiator.
  Cleaned around the leak with a brush and Acetone.
  Placed some JB Weld over the leak, pressed it in with a penny.
  Left the penny in place and let the JB Weld cure.
  Refilled radiator.

Been fine ever since.