A few coolant questions...

[85db]

I checked my level for the first time in about a month and it was way below the minimum level, the car was stone cold when i checked. I topped it up to just above the minimum and went for a drive checked it when i got back after the car had warmed up and it is now reading just under the maximum.
So when is the best time to check hot or cold? If i'd have filled to the max when it was cold then it looks like it would be reading way over maximum after it warmed up.

It's got toyota long life coolant in there but i've nearly ran out, however i did find an bottle of motul inugel with quite a bit in it, is it ok to mix them? They're both red but the motul is a bit more pinky/orange.

[Dyn-Evo]

It should be filled to max when cold: after a run, it should be above max (about an inch?)

When it cools down to cold again, it SHOULD read max (where you filled it to, basically)   s:D s:D  

It could take a few top ups to settle fully after a drain / refill, but if you constantly need to keep topping up, it will mean you have a problem somewhere.......

Obviously re-check the bleed points (heater matrix, radiator) to verify you have no air-locks!

Radiator, loose hose somewhere, heater matrix, head gasket, in that order.......

If you have a slight leak (loose hose clip, etc), it may leak only when up to temp / pressure, allowing some coolant out when driving.
When it cools down again, it may suck air back into the system, rather than the intended suck-back from the expansion tank..?

Now depending on where this leak is, over time, it can sometimes lead to an airlock / coolant system failure due to the steamy air expanding in the air pocket: this can prevent coolant circulation and cause a sudden overheat, or more likely, the nearest hose clipped connection  to pop...!   s:( s:(  

So check all your connections: but monitor it for a while before worrying about any of these........!  s:wink: :wink: s:wink:

It may just need to settle?   s8) s8)

Re: the coolant itself.
Personally, I would top it up with water until youre 100% you have no leaks, etc....

Summer is coming, so you can easily get away with a weaker mixture now, anyway...!  s:wink: :wink: s:wink:  

Ambient temp is up by around 15 degrees over what it was a month ago....

[roger]

Should perhaps add, that my water level goes up and down like a yo-yo, probably an air bubble or something, because i never have to fill it up.

On this basis, keep a daily eye on it (both hot and cold) and see what happens. In theory as long as the expansion tank has got at least the minimum in it should be OK. Don't keep topping up if it stays fairly constant when low, because you may well just be blowing it all out when it gets hot.

Though as Dyno said, also make sure you are looking for leaks. You never know. The advantage of the red stuff it tends to show up quite easily.

[Deadmanwalking]

Hi

I had a lot of this, see here:  l viewtopic.php?f=11&t=36877&hilit=coolant+reservoir l

Mine just settled down after a while, drove me mad in between.

[85db]

Cheers, i'll just keep a close eye on it for now, i don't think it's leaking when stood still, i would have noticed a puddle on the driveway i'm sure. But if it is leaking a bit when driving that could be a bit tricky to track down where it's coming from, seems to be quite slow if it is losing some so hopefully it wont get any worse.