Cooling Dilemna

Was the engine rebuilt recently, or has this been a problem only since a rebuild? Possibly the head gaskets were installed backwards.

Does it cycle up and down or does it climb continuously?
Will

quote:

Originally posted by garth66:
Was the engine rebuilt recently, or has this been a problem only since a rebuild? Possibly the head gaskets were installed backwards.

Not a recent rebuild. The problem seems to have gotten worse when the cooling system was upgraded. Backward head gaskets are always a possibility but they've been on the motor for the past 20 or so years. Its probably our last resort check.

quote:

Originally posted by 4NHOTROD:
Does it cycle up and down or does it climb continuously?
Will

It's a continuous climb once the driving starts.

Pipes under the car clogged?

Hmmm...clutching at straws here, but how about the fans wired in the wrong direction so that when the car is stationery they move air through the radiator but when moving they are fighting the air flow.

Just a thought here,
On my car the same thing happened. After it costing me an engine, it was narrowed down to the top radiator hose inner lining breaking down and de-laminating (or whatever) resulting in not enough fluid flow through the system. Discovered it by a fluke after the engine was out for a rebuild as it looked normal from the outside.
Steve

The coolant is not flowing because the stat is stuck or the water pump is not working properly.
I'd replace the stat first. The fans and rad are obviously new so it's probably at the other end. Is there alot of heat being pulled from the rad at idle and when you're revving it at a stand still?
Will

Thanks for the think tank work guys! The thermostat has been changed twice and the water pump removed and inspected. The hoses are all new. The fans have been checked for orientation and operation and are OK. Just about the only thing that we haven't done is check the pipes but we have good flow at the surge tank and the radiator gets hot. I guess that the pipes could be partially clogged allowing some but not enough water through.

I know you replaced the stat twice, but you could try running without a stat. If it runs dead cold always, then you have a flow problem.
Will

You said that you replaced the hoses so this most likely is not the problem, especially on a Pantera. I had a mustang that did the same thing I found that the bottom radiator hose would collapse when driving the car. I know that the hose entering the water pump on a Pantera is fairly small but it does have a bend and just maybe it could be doing the same. Any way it does seem like you are not getting coolant to the engine at higher speeds. When I had a bad thermostat it even got hot at idle then even more when driven, but my radiator was cool to the touch.

...Is the Coolant Mixture 50/50 Distilled Water to Anti'Boil'? This can make a Difference...

Dennis,
I assume you have verified the right thermostat and brass bypass?

Also when I replaced my radiator I talked to Jerry @ PI Motorsports and asked him about it and he said he does alot of reversels back to the original standup configuration because of overheating. If you look at the area behind the radiator you will see that the under side has an angle to the sheetmetal to deflect the air down and under the car. If you laydown your radiator then the air is directed straight into that body panel and confused/not free flowing, this also creates a problem at speed as the air is confused and needs to be forced threw the radiator with a fan, standing up the air goes threw as designed and the fans shut off. Anyways check this out: http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/4670077164/p/1
I used the Mirah Fans and puller fans, no problems since, even at 160+ continues runs inthe Desert.

Mark

quote:

Originally posted by MARLIN JACK:
...Is the Coolant Mixture 50/50 Distilled Water to Anti'Boil'? This can make a Difference...

Distilled water is the worse thing that you can introduce into a cooling system. This is from my No Rosion/Hypercool manufacturer:

While it certainly is true that distilled water’s purity prevents electrolysis and scale/deposit formation, it unfortunately comes with a potentially very damaging side effect. During the distillation process, water is vaporized into it’s gaseous phase, so all impurities are left behind. These impurities include a number of minerals, including calcium and magnesium – the two components of “hardness.” The water is then condensed back into it’s liquid phase, so the resulting liquid is pure water – in fact, some of the purest water on earth. The problem is that when water is distilled, or “stripped” of impurities, the resulting solution is composed of chemically imbalanced “ions.” This leaves distilled water “electrochemically hungry,” so it will actually strip electrons from the metals in a cooling system as it attempts to chemically re-balance itself. As it chemically removes electrons from the cooling system metals, it does damage that will eventually lead to leaks and system failure."

Even when using additives like antifreeze the distilled water will strip what it needs from the additives shortening it's life.

Pipes were verified clear and the car has been run without thermostat. One member suggested a leaking head gasket. He says that on his Ford Bronco, he had a similar problem and it turned out ot be a very small leak where the combustion chamber was heating the water jacket in the head. We were also thinking backward head gasket(s). He's pulling the heads just to check it all since we're running out of options.

ever think of a bad guage? iam going thru almost the same thing right now . idle no problem ,run goes to red. changed everything. tapped on the temp guage kind of hard it dropped almost 20 degrees then climed a little. waiting for weather to run it with the guage in may hand to see what happens sonny4233

A thermo gun should be your best tool. Check temp differences between the inlet and outlet and if ok you can eliminate the cooling side of the system and concentrate on the engine. Check for temp fluctuations between the front and rear of each head as this may locate spikes to determine a problem. If the temp is the same through out I would focus around the bypass section and that the donut and proper thermostat is correct, there is a special thermostat for a cleveland and I think that has been mentioned. Also just a guess and not sure how this will effect just make sure that the rad hoses flow the coolant through the rad in the proper direction as I think the coolant flows from the bottom of the rad to the top, someone correct me If I am wrong. JMO, Derrick

We checked the gauge, added a mechanical water temp gauge for testing and also used a laser thermometer.

Running out of the obvious solutions, he pulled the head to check the orientation of the head gaskets and also to see if there was a head gasket leak heating up the water passages. The head gasket looked good but he did find that his intake gasket was leaking big time and sucking oil into his combustion chambers. His valves were oil crusted. He had been losing quite a bit of oil prior. Could this be the cause of overheating? Loss of vacuum or hot oil heating up the gas charge?

Are you sure it's the correct thermostat? I bought a thermostat for my pantera not knowing the 351 Cleveland uses a unique thermostat.

Yup, we know that it is a specific one and even changed it twice to make sure that it wasn't defective

The intake leak could be causing a lean mixture at RPM (driving) which will produce extra heat.

As mentioned earlier, closely check the 90 deg hose that attaches to the water pump inlet. This hose can collapse as the flow of coolant increases with engine RPM, especially with a high volume water pump. This is the reason that some molded radiator hoses have a spring inside. You might go to your local auto parts store & buy a hose (of the same diameter) that has a spring in it. Remove the spring & insert it into the Pantera hose.