So last night I threw a little coolant in my radiator because it seemed a little low. This morning I pulled in my school and one of my friends points at my truck and says its smoking. Sure enough it was. I popped the hood and it was the radiator so I figured it must be leaking right? I mean why else was it low last night? So I pulled of the skid and I dont see any sign of leaks. I pulled of the top radiator hose and an a*s load of steam came out. I'm letting it cool down now, but I'm at a loss. Could I have over-filled the radiator IDK I'm at a loss here. Quick response would be much apreciated!



Heres the underside of the radiator. As you can see its bone dry. Ignore that bit on the hose, that was me

Bump. Come om guys. Anything?

If it's smoking out the exhaust, bad joojoo. Blown head gasket. Best case is a pinhole in one of the hoses. Check the passenger floor board for moisture, blown heater core.

Yeah headgasket is fine, that was the first thing I checked for. Thanks, I'll look. In the meantime, any more suggestions would be greatly appreciated!

Would a blown heater core cause my engvine to overheat?

Well, a bad heater core will leak coolant out onto the passenger side floorboard, and with an ever decreasing amount of coolant, your engine will overheat.
But you would likely notice the heater core leak. You might not though, if the leak is still small. Fill it back up for right now, and put everything back together. Do you have a sweet smell in the cabin?

Run the truck with coolant at its max limit. See if you overheat, or if your just still losing coolant. How long has it been since you've replaced your water pump?

As far as a heater core is concerned, I felt the floorboard and it is dry. If by "sweet smell" you mean a coolant type smell then yes, I most definitely smell coolant in the cabin. I think I will drain the radiator and refill it with coolant and water. Also how much coolant and water should I put in the radiator? Thanks

Edit:

I do not know when the pump was replaced. How would I check that?

What I would do:

1) I would go and either get coolant from your local dealer, the red stuff.
Or go get some 50/50 coolant, which has coolant and water pre-mixed.
2) You can fill the radiator to its limit, and then fill the reservoir to about halfway. (This helps avoid overfilling)
3) Start the truck up, and let the engine get to normal operating temperature.
4) Shut it off and let the truck cool back down for awhile.
5) Re-inspect the radiator for its fill line, as well as the reservoir. Fill the radiator back up and filll the reservoir to the MAX line.
And then I would keep an eye on it daily.

As for the water pump, if the vehicle doesn't have a maintenance record, then your best bet is to physically inspect it. Failing water pump gaskets, that seal the water pump to the block, can dry-rot and start leaking. The worst part about a failing water pump/gasket is that they don't show too many symptoms, other than disappearing coolant. You will smell a sweet chemical aroma. The engine burns the dripping coolant before it can reach the ground, so you don't see spills underneath your vehicle.

Also, you can get the coolant system pressure checked at your dealer or local mechanic. This way they can take the guess work out of it all. They could tell if its your water pump, radiator, head gasket, etc.

Good luck!

So I started pouring coolant in the radiator. I only had one gallon so I used the water hose to fill it up (I was going to go straight to autozone) anyways the damn radiator doesnt fill, instead it stats pouring (and I mean pouring) out from underneath the car. WTF! So I followed the water. It leads up to the back of the engine. Right under the manifold. There is a hose that runs into the block and the contecting peice seems to have coroded. Have any of you had this happen before? I have never heard of this problem on the 4runner. Help!

Pic of water running out of the truck:

I found your problem.
Well, I was going to tell you to put out some cardboard to find the leak...

Make sure that the hose is the culprit, and not something above the hose, leaking down onto it. Have someone pour water through your system, and diagnose it that way, so your not wasting coolant and polluting. Good call on just using the water. Thats one helluva leak my friend. Is there a physical hole in the hose?

Follow the entire hose and tell me where it starts to finish. Your going to want to fully remove the hose, and track where the factory ran it through. You'll want to reinstall it the same way. This is because of hot components in the bay, it might burn a hole straight through the hose if its ran incorrectly, and sits on a hot surface. So follow the experts.

Take the hose to your nearest auto parts store, and they should have a roll of various hose sizes in the back. Get the same diameter, obviously. The Advance Auto by my house has Goodyear rubber for their hoses, so I trust it. Just get the identical length and replace it. Get new clamps for the hose as well. I'm sure their rusted up, or at least insufficient at this point. Get some metal hose clamps that screw tight, like these:


Check for a waterfall underneath your vehicle, and then go from there...

Isn't that the coolant lines running to the rear heater? You should be able to bypass those easily so you can fill it up right away, see here for pics Rear Heater Lines

Well I figured out what was going on. You guy were somewhat right. The heater was leaking but it wasnt the hoses. This is really weird: the place where the hose pugged into is coroded. So basically I need an entirely new manidold. Im gonna have it towed to a shop tomorow. Im gonna go cry myself to sleep now

Aw man, I'm sorry to hear about that. I was hoping it would only be the hose.
Well, you can always save yourself some $$$ and attempt the job yourself. There are many knowledgeable people on here to get you through it.

Exactly, try it yourself. There are a few threads that show how to do the valve cover gaskets. That gets you 90% of the way there.

Damn, sorry dude. Arm yourself with some new parts, an FSM, and some brews and wrench away.