Hi, having overheating problem.

[CREWZIN]

" With the a/c off, running the heater full speed kept the car at the mid point on the gauge."

If your pretty sure it's not the head gasket....
I wonder if that could be a clue. Turning on the heater gives the water more places to flow and cool down, whereas the water stays in the block and radiator most of the time. If your water pump isn't working properly or radiator was clogged, that would cause overheating. Can you start the car, take the cap off (you might have to lower the water level a bit) and wait till it warms up to see the water moving around when the thermostat opens?

[Theophilus]

That is what I was just pondering. I'm going out and check for flow.

[Theophilus]

Here are my results. The thermostat open with, it seems to me, very slow flow. I reved and held it about 2500 rpm and got hot water spraying from the outlet. I couldn't really tell if it was flowing, naturallybecause of that. Sign of a blown gasket?

[CREWZIN]

Something to read....

WikiAnswers - What are the signs of a blown head gasket

[CREWZIN]

I was on one of the other PT forums and ran into an owner having overheating problems. Turned out to be the water pump. Here's the last thread.....

Here's the lowdown. I replaced the thermostat...no difference. I replaced the radiator cap...no help. Flushed and refilled with new coolant...no help. Replaced the water pump...bingo! Apparently, when these water pumps go bad, the shaft spins inside the {plastic} impeller and it doesn't circulate the coolant. When they are cold, the shaft spins the impeller...but once it's warm, the shaft spins INSIDE the impeller since the plastic expands more than the steel shaft. Hence the feverish croozr.

Anybody reading this: The above problem is why we tell everyone that's thinking about doing the timing belt to change the water pump (and a couple other things) while they are having the belt done because even though the water pump might have lasted till your time for the timing belt, there's plastic parts inside and they will eventually wear out and it's the same labor intensive job to get at the timing belt as the water pump. Might as well do them at the same time.

[Theophilus]

Thanks for the headgasket link and about the waterpump. That make sense about the impeller. I wouldn't have imagined they are plastic! I'm having none of the headgasket symptoms. My BIL is going to check out the waterpump, radiator and the headgasket at the shop he works at tommorrow.

[Theophilus]

BTW another symptom I forgot to mention is that even at high speeds, when according to what I've read, the fan doesn't operate, the temp will still not get low, it actually increases.

[CREWZIN]

The fan on either speed doesn't work (or turn on) above 35mph as you just mentioned. There's enough air coming thru the front of the car too cool it off, not make it cool but at least not let it get hot. If yours is still getting hot that's probably because the water pump isn't working as we are saying.

My fan burnt out in Orlando (90 miles from home). It overheated and blew the anti-freeze out the overflow tank all over the engine. I waited till it cooled off, filled it up (only thing I had was plastic cups of cold water from a 7-11) and made it all the way home because most of the way it was highway driving (fan not needed). When I got to my town I drove watching the lights and even stopped, then went through a couple of them so my PT wouldn't have to stand at one point and wait for it to turn green.

[Teekypt]

and made it all the way home because most of the way it was highway driving (fan not needed). When I got to my town I drove watching the lights and even stopped, then went through a couple of them so my PT wouldn't have to stand at one point and wait for it to turn green.

LOL! This sounds like when I had a Toyota Tercel and the fan wasn't working (before I bought Shugga Plum). I drove that little sucker for an entire month with the fan not working...as long as I was driving highway speed, it kept the engine cool enough. When I had to stop in traffic, I rolled down my windows and blasted the heat! It worked!!!!

[Theophilus]

So we dropped it off at the shop my BIL works at this am. They called and have determined that the radiator is clogged. I can believe that since the coolant did look like mud and I neglected to do anything about it when I noticed it over 2 years ago. I think that would explain the slow flow I seemd to be getting and the spitting. I think it would spit because the coolant isn't reaching the the water pump fast enough.

Anyway $400. I just wasn't going to drive the 40 miles round trip to get it from the shop then do it myself in the 90+ heat we're having. We received our dot gov cheese check so at least we didn't have to get into our savings.

Thanks for all the help. I'll let you know how it goes.