View Full Version : radiator to overflow bottle question

06-26-2006, 01:16 PM
quick question. (car is an ST162 3sfe/S53 - check it out in members ride at your leisure :bigthumbu )

The hose from my radiator to my overflow bottle should let coolant out of the radiator and into the overflow bottle as it heats up, no? And then suck it back into the radiator as it cools down?

I ask cos I've got no flow into my overflow bottle at all when the car is warmed up.

The car isn't overheating (temp gauge sits under half way all the time, even in traffick) I was just wondering in case I'm at risk of blowing a hose or something cos the pressure isn't being released as it builds up.

06-26-2006, 01:55 PM
It should yeah... I've run my celica for hours and hours without any runoff. If you're really worried, replace your radiator cap.

06-26-2006, 03:06 PM
I had a mysteriously empty coolant overflow until I realised what it was. The head gasket was allowing exhaust into the coolant and so blowing out of the overflow bottle taking any coolant with it.

Have you heard any strange exhaust noises when the foot is down?

Have you taken the radiator cap off when the engine is cold and running?

What does the coolant smell like?

It may be another cause but it is worth checking the above.

06-26-2006, 03:45 PM
the head's okay I reckon.

I was trying to see what the coolant was doing from cold to operating temp when I realised the coolant isn't overflowing into the bottle as the engine warms up. At half op temp I thought "this is weird, lets take the cap off and see what's going on." I copped a warmish/hot spray of coolant. I was careful takin gthe cap off so any excess coolant could travel into the bottle as cap came off. None did.

I'm just making sure I'm not and the overflow bottle is just for looks. I'll get a new cap (thanks 4thgen) and see if that fixes it. I'll also poke a stick down the connection to make sure there's no sh!t in the way. Cheers guys.

Hey Nobody, gonna be up to watch the Aussies take on Italy?

06-26-2006, 04:13 PM
What time and channel is the game on? I'll be heading down to the folks house where they have Satellite and HD. WOOT

06-26-2006, 04:48 PM
sbs, kick off at 12:30AM. This is of course for people in Australia.

06-27-2006, 01:02 AM
Ok, hold up.
The tube feeds excess coolant into the reservior, but only when the pressure in the system exceeds the spring in the cap.
So if you have a 12 psi cap, fluid will only flow when the cooling system is above 12 psi.
Which won't happen while it's warming up.
It takes a long time.
Now if you drive for an hour, stop, and let the car run for say 10 min, and you have nothing in the reservior [actually, you should have some to start anyways], then you have a problem.

06-27-2006, 02:35 AM
okay, I'll give that a shot. Thanks Jeremy.

I never fill the overflow bottle when I fill the radiator. Do you reckons that's bad? Like I said before, the car doesn't get hot but it has been losing a little coolant lately.