Who's been drinking my anti-freeze?

Weird things are going on with my 87 4Runner's cooling system. I seem to have to add a quart to the radiator about every 2-3 days.

Were is it going?

There are no puddles underneath. No visible leaks in lines or hoses. Thermostat is new. Radiator has just been replaced (two days ago.) Heater core appears to be fine. No coolant smell or steam in the cab. I don't think its a head gasket. The oil in the pan and valve cover (I looked when I did the thermostat) are clean, no milkshake.

So were is my coolant going? The only thing I can think of is I over filled the puke tank, forcing out the extra fluid when it heats up. But, again, no coolant is visible in the engine bay, and I see no steam when I lift the hood.

Any ideas, tips, or tricks? I'm sick of having no heat.

Air bubble in the system?

Try turning the heat off, if it stops leaking the leak is in the heating system, if you don't smell coolant, probably a heater hose that stops leaking when the system cools or drops enough to stop circulating.

Pressure test it. I've had a few cars come in the shop with mysterious leaks. They only leaked under pressure so there was no puddling and little visible evidence.

Going out the exhaust is the only other option if there IS no external leak and you're certain it's not getting into the oil. A quart every few days isn't fast enough to be noticable in the exhaust.

On the other hand, it's also slow enough that it could be burning off before it hits the ground.

What engine is it?

This is the same thing that's been going on with my Cherokee for the last..... 3 years.

Go find a quiet backroad and pull through the first 3 gears to redline, pull over and look for spraying. If this doesn't find the problem, pull the plugs out and look for a white one.

22RE is the engine. I worry that it might be dumping into the exhaust. I had a shop I trust pressure test the system. That's why I replaced the original radiator. There was a pin hole and the phosphorescent green color of a dying brass radiator.

BHG. They do that. Mine went at 200K, but had been going through a cup or two per oil change for about 80K before that.

And put metal timing chain rails in there while you are at it.

I agree with Boost, pressure test it. Dont forget to check the rear heater core if it has one. Hope it isnt a hg, test strips are readily available to ease your mind about that though.

Mine was doing that and it was the head gasket. Leaking from the water jacket into the #4 cylinder.

P.S. lets see some pictures of the runner!

Head gasket, probably not a large failure, but more of a seepage. My former neighbor's '88 did that for awhile before it finally failed.

I need to go back into town and see if it is still sitting at the house of the guy he sold it to. I wouldn't mind having that one.