Coolant level keeps dropping

[Dav81]

Hello everyone

I've noticed the coolant level keeps needing topping up - especially in this hot weather and normally after the car has been standing in traffic. The engine isn't overheating, and I can't see any obvious leaks. I've checked the engine oil, and its not milky (so I'm guessing the head gasket isn't blown). Both fans work when the AC is on, but I'm wondering if they aren't working properly to cool the radiator. Any suggestions/advice/tests I can do will be much appreciated,

thanks folks

Dav

[steveo3002]

any white powdery marks anywhere near a hose join ?

otherwise you can get dye kits to add to the coolant and a special torch highlights it , or a pressure test kit which would force it out of the leak

[Dav81]

Hello Steve, thanks for the reply.

I replaced the expansion tank as that was leaking, but it doesn't seem to have solved the problem. I haven't seen any obvious white powdery residue around any pipes. Might invest in a pressure kit though, see if that reveals anything. Cheers Steve

[Dav81]

Could anyone recommend a pressure testing kit please? One that will fit onto the expansion tank?

thanks

[imagineifyeswill]

What Make and Model of car.

[Smiljan]

A pinhole in the radiator or weep from the water pump are both common leak areas that are hard to spot on many different models of car.

[PositronicRay]

Dav81 said:

Could anyone recommend a pressure testing kit please? One that will fit onto the expansion tank?

thanks

If you Google it you can make your own. I dropped the pressure on a spare tyre and used that. Connected to the expansion tank/rad return pipe. This way it tests the pressure cap too.

[GreenV8S]

Dav81 said:

Could anyone recommend a pressure testing kit please? One that will fit onto the expansion tank?

thanks

They're widely available and not expensive. The one I use is branded Franklin but I doubt they make it and I'm sure there are dozens of other brands just as good.

[Heaveho]

I thought I had a similar problem a few years ago on a car I've owned for a long time now. Kept noticing the coolant level seemed low and would periodically top it up to the max level mark on the expansion tank, only for it to have dropped to minimum again when next checked. I came to realise after a while that it's probably blowing a small amount out of the breather and just finding it's own level. I stopped topping it up, and it never drops any further than just above minimum, so stopped worrying. The level in the rad is always at the top when I take the cap off.

This is on a 2003 Evo 8 for reference. The situation above has been the same for many years now without a problem. Unless you get to the stage where there is visibly no water in the tank, or you know that what it's currently doing is unusual to that vehicle, it's something you could try?

Edited to add......is this on a Toyota or Lexus by any chance?

Edited by Heaveho on Tuesday 6th August 16:55