Here's the trouble with my 95 Runner,

This morning I warm up the truck, drive about a mile and notice the temperature gague is almost peged. I pull over, pop the hood and there is a lot of steam and boiling. So i get a rag and pop the radiator cap . Blamo a fountain of coolent and watter everywhere (not so smart, but hey it was early) . So I get home after about 10 stops and starts and jump on Yotatech. After a search I decide to replace the thermostat as a starting point. After a PITA it's replaced and after a test run I get the same results. I boil the old thermo on my stove and it seams to work fine. So here's where I'm at now, overheating, top hose is hot, bottom hose coming from thermo not hot, cold air from heating vents even with overheating. What's up guys any Ideas?

Thanks

 

Any Help? Is there any way for me to know if it's the water pump?

 

Shouldn't be the water pump. I mean even if your impeller was bad or you snapped the shaft you'd get some kind of convection through the engine. This is blockage somewhere.

If you're not getting warm water out of the radiator bottom, I'd suspect something with the radiator. How old is it?

 

How often do you flush your radiator?
You may want to back-flush your radiator and force any debris or corrosion out of the system.

 

I wouldn't be so quick to rule out the water pump. I have seen this result from a bad water pump, though this isn't to say that this is your problem. I would feel for water movement by squeezing the hoses,(though it seems you have already discovered the result of that test). It does sound like some sort of blockage though, if not at the water pump. Post your findings, I'm interested in what you find.

 

Is this a V6? When you refilled your coolant did you pull the top hose and directly fill the block? Check your PMs Daryl

 

Well, I guess the normal thing to do would be to check for smoke coming out of the exhaust. Look under the oil cap for any milky substance.

 

I too wouldn't rule out the water pump. My 22re spun the impellor and I started to overheat, but it wasn't a toyota water pump, it was a cheap Autozone one (truck has 177K - 2 water pumps so far). Funny part is the pump never leaked. How quickly from a cold start does it take to overheat? If you start it with the cap off the radiator, you can usually see flow once the thermostat opens.

 

Scott 72

It overheats within about 5 minutes.

 

Hey 00flaw, I sent you a PM with my # in case you want some help with this. DarylD

 

Any updates ? Did you get it fixed?

 

My '88 did the same thing two weeks ago on my way home from work.
Daryl had me check the water pump and sure enough the impeller had frozen up.
Are you getting any smoke from the timing cover area.
My timing belt was trying to turn the water pump pulley and would smoke trying.

Let us know.

 

Well a friend and I tore into the engine this weekend and after 5 hours of a serious PITA we got the water pump replaced. But unfortunately we marked the timing belt with a grease pencil that promptly got totally smudged away. So as we were trying to fit everything together in the waning daylight we kinda winged it and once it was all together and I turned the engine over, no start, the timing obviously screwed. So I don't know, until I get in there and figure out the timing issue I will not know if the new water pump fixed the problem. I am worried though that it won't because the old one seemed to turned smoothly by hand:pat: .

 

Where in Seattle are you ? If you want I can help you get timing set back right. Daryl

 

Not to hijack a thread, but does anyone know an easy way to re-set a distributor that is "out by a tooth"?

 

I hope you left the distributor alone when you did this. There are timing marks on the cam and crank gears from the factory so line those back up and give it a shot. You should fire it up before you get all the timing cover and everything back together. Never use the belt as a guide to line up the gears, you always want to scribe a line on the gears and the engine block to know how to line them back up. Just an FYI for next time.

Hope you did fix the overheating problem.

 

Why is your distributor out by a tooth?

 

I had a very similar overheating problem after I flushed my coolant some time back. What I found was that, at least in my case, there is very little differnece between having enough coolant and too little coolant in there. This frustrated me to no end, you can find my panicked posts here if you look. Anyway, what I ended up doing was running the motor with the radiator cap off. When the fluid level dropped I would trickle more in there until it was full, over and over until it couldn't take any more.

As I look back on it, I think there was probably a bubble in there somewhere, and this method purged it out. Just something else to try, because your symptoms are exactly what I had.

 

Well for me at least the cause of the overheat is now pretty irrelevant. I took the runner in to a mechanic to have him give it a once over. He found a crack between my 1 & 3 head and the #2 cylinder is dumping compression into the cooling system. So until I can afford a new engine I am carless in the rainy season, in Seattle.:alien: