Pantera overheating!!!!!!!!!!!

[bearphoto]

Pantera overheating, I know, the words pantera and overheating are pretty much synonomous, go together like hand and glove, bat and ball ect.

But here is the problem: My buddys pantera, we are trying to fix it up so he can drive it on the Power Tour. I am taking my GTA. Pantera's have had heating issues since the car was made, but in Joe's case, we jumped in with both feet to fix his hotter than desired operating temperatures, we replaced the water pump, theremostat, and the "hat" piece directly under the thermostat in the intake manifold, had the radiator rodded out and cooling fans replaced. Of course, all hoses, belts and a number of other things too.

Another big problem with those cars is getting the air out of the cooling system. Remember the radiator is in the front and the engine is in the back, with long hoses running back and forth under the car. Lousy design i know but thats for another discussion. So we need your help in trying to figure out why the car can idle one day with good temps then the next day it overheats just idling in his yard. We also live at 7000 feet so even yesterday it was only about 50 and overheated while idling. Today we were to take it on a run with the corvette club and dont you know the car did'nt go 5 miles before overheating and Joe turned around disgusted and went home wishing he was driving either a Chevy or a Pontiac, especially a Pontiac.

Anyway, there is a small possilibilty there is still some air in his cooling system but joe has burped out most of it over the last month and was able to replace the air with 3 qts of coolant. But, again he did not get 5 miles today. So, what else can it be? I have asked him to go to the auto parts and get one of those "strips" to test for exhaust in the water incase he has a head gasket issue. but no white smoke in the exhaust or oil in the water so he is going to do that. Second, he has not checked his timing "ever" but the car does run well, well except for over heating. He has not checked the carb or the idle screws or anything for running lean. that needs to be done yet.

So, mechanic guru's, help ole Joe out so he can take his pos Pantera on the power tour! After the power tour if his car can make it, i think he will buy a Pontiac or maybe a chevy. Oh, I'm too funny. He will be mad at this but he is madder at his car right now so i can get away with it.

Thank you for any help you can offer.

[TheSilverBuick]

Re: Pantera overheating!!!!!!!!!!!

My first question/clarification is what method are you using to determine it's overheating?

If there is a problem getting all the air out of the cooling system an air bubble could be spiking the temp gauge when the true temp is lower. But at the same time if an air bubble reaches the water pump it'll be tough to move water and could simply be a purging the air issue.

I've seen tons of Pantera's run the Silver State race, I don't know what they are doing for cooling though :-\

[Leon]

Re: Pantera overheating!!!!!!!!!!!

I've heard there is a problem with the sensors on that car, I'd use a good gauge or infrared temp monitor to determine if it really is overheating. I've used one of those to determine if the coolant was actually flowing in a system like I thought. Valuable tool.

[cstmwgn]

Re: Pantera overheating!!!!!!!!!!!

I think I would start with a pressure tester - autozone here will loan them to you for a $75 deposit.
What brand thermostat?
You might want to test it in a bucket of water to see if it is working properly - just because its new doesn't mean it is good.
Does he have a purge valve in the system?

Tell Frenchie here are some links that might help - sorry if you have already been to these sites.

http://www.mtco.com/~pantera/problems.htm

http://www.spkorb.org/panrad.html

http://www.pim.net/TurnkeyCooling.html

[joe_rocket45]

Re: Pantera overheating!!!!!!!!!!!

I find that if the initial is high (even locked out) I can idle around longer, always try to run a large albumin rad and generally no thermostat. I don't mind 140* temps and it gives more leeway to work with when you have to do a lot of idling. as long as the oil comes up to temp it's all good.

of course npthing works if there is air in the system, be sure to get the front end way up high and burp it with the engine running, don't be scared to rev it up to dislodge any stubborn air pockets either.

[Eliteman76]

Re: Pantera overheating!!!!!!!!!!!

Dude, NO NO NO, must run a tstat in a clev. Got get the robert shaw 180 degree tstat from summit racing.
Make sure you run the donut plate below the tstat, in the 351c that is part of the bypass for the coolant.

Seriously, I don't know everything, but in screwing with 70's torinos that run stock or mild 351c's, a good t stat is a must.

Unless you like crap like accelerated bore wear, and other issues.

Go talk to the guys at the 335 forum.

http://www.network54.com/Forum/119419/

Just trying to help man!

**edit, sorry, forgot the t-stat, here it is-

http://www.summitracing.com/parts/BRA-333-180/

I would love to see your Pantera out on the PT.
Awsome cars.

[bearphoto]

Re: Pantera overheating!!!!!!!!!!!

He has a new t stat in the car, dont remember brand, could be from napa but he has the "hat" as they are called in the intake below the stat. there is no purge valve in the intake but we did talk about trying to put one in. What are we basing his overheating on? His temp guage. I have told him he should verify they are correct by using an infrared but he feels his guages are accurate. They appear to work and the fans come on at the correct temps as shown on the guages, radiator has been bored out and cleaned, dual fans have been worked on and are working correctly. Joe should be coming on here this evening and can work through some of this. Keep those ideas coming, thank you.

[bearphoto]

Re: Pantera overheating!!!!!!!!!!!

So here is another question. I have told him he needs to replace or be able to check his radiator cap. I have the snap on cooling system tester kit but it wont work on his cap as its covered with a billet cover over the cap which prevents me from testing it based on how it fits with the billet cap. so i'm thinking perhaps if his cap is only holding 8-10 lbs when its designed for twice that, could that contribute to his heating issues? He can idle the car for a day, no issues. the next day does the same thing and it overheats. today he drove less than 10 miles, no issues. we meet up for a cup and then leave and before he gets 5 miles the temp guage is up to 260 degrees.

Maybe a grenade would help some?

[TheSilverBuick]

Re: Pantera overheating!!!!!!!!!!!

A bad cap can definately do that, some cars/engines are more sensitive to caps than others.

[tedly]

Re: Pantera overheating!!!!!!!!!!!

How would a weak radiator cap cause intermittent overheating? I'm not saying it won't, but wouldn't it just cause coolant loss? I know that this would lead to overheating when enough has been sprayed out, but you would be able to see the pattern left by the leak (right?). Forgive me if it's a dumb question, just trying to understand it. :-\

[Scott Liggett]

Re: Pantera overheating!!!!!!!!!!!

How would a weak radiator cap cause intermittent overheating? I'm not saying it won't, but wouldn't it just cause coolant loss? I know that this would lead to overheating when enough has been sprayed out, but you would be able to see the pattern left by the leak (right?). Forgive me if it's a dumb question, just trying to understand it. :-\

The pressurizing of the system allows it not to boil out with steam. The cap has a pressure rating that it's supposed to keep the system at. Often the wrong pressure cap can cause the same problem.

Check the gauge first. Why spend hundreds of dollars on parts if you're not even sure it's overheating?

[tedly]

Re: Pantera overheating!!!!!!!!!!!

The pressurizing of the system allows it not to boil out with steam. The cap has a pressure rating that it's supposed to keep the system at. Often the wrong pressure cap can cause the same problem.

I understand the relationship between pressurization and boiling. If the problem is the cap, there should be obvious coolant loss and a spray pattern around the cap (right?). Also, the problem would be constant instead of on and off (right?). Again, just trying to understand... :-\

[Scott Liggett]

Re: Pantera overheating!!!!!!!!!!!

I understand that. My friend Carl and I are trying to figure out why he keeps losing water out of his engine while no water seems to spraying, dripping, leaking, or anything else. It's just evaporating and we can't find out why. It's not overheating either.

[Eliteman76]

Re: Pantera overheating!!!!!!!!!!!

On the 351c, there have been a lot of issues of companies like Stant mixing 351w and 351c thermostats at parts stores.
I would do two basic things.
1. get a basic mechanical temp gauge, and screw it into front port on the block.
2. $24 for the correct robert shaw 351c-specific thermostat, and a $3 gasket.

Just trying to help man!

[joe_rocket45]

Re: Pantera overheating!!!!!!!!!!!

what does that stupid by-pass do? by-passes the rad. lots of radiator hose and restriction, makes it worse. no need for it IMO, this is a "hot-rod" not a turn the heater on in 2 minutes ride is it? I'd remove it and run a water restrictor too:

http://www.summitracing.com/parts/MOR-63440/

you can also cut the center out of an old t-stat to test with, it will make burping ALL the air much easier.....