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I have a 1974 Pantera which I've updated the cooling system using the example set in sticky #3 from this forum. Fluidyne Pantera radiator with dual sucker fans, condenser in front. Weiand waterpump, not modified, with a water pump reduction pulley.  Above 90 degrees ambient the 260 temp guage, with Pantera-Electronics compensator, appears to peg high at speed, as soon as it comes back to a normal cruise speed or idle it will read about 192.  To me this indicates an air pocket.

I'm purging the system again this morning with the real elevated,  13psi cap, ran it up to about 110 degrees and shut it down, purged the air and got minor overflow out the tube. Fluid topped off before running. Topped off again and ran until cooling fans turned on and shut down, purged and overflow was slightly more tha 1 quart.  Took temp reading on coolant and it was 150 degrees.  Ran test a 2nd time, holding rpm at 2000 for 3 minutes, purged and overflow close to 1 gallon, temp reading 190 degrees.  Also in the the past I have pulled the temp sending unit and water poured out.  I'm not familiar if that water coming out would be before or after the thermostat..

I'm stumped as 150 would not be opening the kool-flow thermostat it seems.  Perhaps the waterpump pulley should be returned to oem?

I'm open to suggestions.  FYI, I've tried in the past to loosen the water ports in the block with no luck, they are the square head plug not the socket head cap screw.

 

Last edited by maraudermike
Original Post

Has your motor been rebuilt? I have heard in the past with a Cleveland that refused to cool properly, after being rebuilt that the head gaskets were put on backwards and this caused cooling inconsistencies / problems.

I am sure there will be others that chime in and have a better understanding, but hopefully you can cross this scenario off your list. Good luck.

I thought that air pockets on the sender read low, not high. 

I’m sorry, but your description isn’t really clear as to whether the car is truly overheated or not. 

it sure sounds like a gauge or electronics problem to me.

 

if the temperature was pegging on a high speed run and then you slow down there’s no way your cooling system would instantly return to 190°

Are you burping fluid after you stop?

 

can you get someone to ride in the passenger seat with an IR gunand get temperature readings when the gauge is pegged and when it’s normal?

 

Good Luck -

Rocky

For a start, every Pantera owner should have one of these: 

https://www.amazon.com/WIN-MAX...591459348&sr=8-7

It's a vacuum filling device for your cooling system. It pulls a strong vacuum in your cooling system, then sucks the coolant out of your 5 gallon bucket, that's sitting on the floor beside the car, and fills your cooling system. No more spilled coolant and no more trapped air bubbles. It's a diagnostic tool too because it allows you to leave your system under vacuum for as long as you like, to make sure there are no leaks. Here's the best part. The very tool in the amazon link used to cost $155 at Summit. Snap-On also sold this exact tool for over $250 but now Amazon sells it for less than $50!  

Vacuum Device

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  • Vacuum Device

Good luck, Mike!

You might try and keep an eye on the voltage of your car during your high speed runs as well.  You can get one of those volt meters that plugs into the cigarette lighter, or hook a meter to the hot side of the fuse box. 

There are some threads around here on the temp sender resistance - I THINK it gets lower as the temperatures increase...  is it possible that the sender is shorting under the vibration of your high speed operation?

 Again, good luck!

Last edited by rocky

The gauge pegging at speed sure sounds more like a high voltage than erroneous reading. Normally cooling at speed isn't an issue with increase air flow through the radiator. Do you have the fans with an integral shroud? I have know cases where they become restrictive to airflow at speed, but that was in excess of 150 mph. Is it possible they are being spun by the natural airflow and acting as generators during high speed runs? I have also known fan blades to be on backwards or wired backwards as well, they can still push air at lower speed but not counteract the increased resistance at high speed.

Try driving in a lower gear at sustained high rpm to help determine whether it is an airflow across the radiator or water pump / coolant issue.

@davidnunn posted:

For a start, every Pantera owner should have one of these: 

https://www.amazon.com/WIN-MAX...591459348&sr=8-7

It's a vacuum filling device for your cooling system. It pulls a strong vacuum in your cooling system, then sucks the coolant out of your 5 gallon bucket, that's sitting on the floor beside the car, and fills your cooling system. No more spilled coolant and no more trapped air bubbles. It's a diagnostic tool too because it allows you to leave your system under vacuum for as long as you like, to make sure there are no leaks. Here's the best part. The very tool in the amazon link used to cost $155 at Summit. Snap-On also sold this exact tool for over $250 but now Amazon sells it for less than $50!  

Vacuum Device

That cooling system pressure tool is great for getting air pockets out of the Pantera cooling system! No more jacking the back of the car up and trying to force the air out and other issues. I recommend that kit for anyone that works on their Pantera.

I have just bought one of those vacuum systems from Amazon as recommended above.  However no instructions came with it.  Hope I'm not being daft but can anyone tell me the best way to use it on the Pantera.  

Also I think my temp sender fitted in the block maybe incorrect.  I fitted a temp probe directly into the coolant filler bottle and temp never went over 190F but on the Veglia gauge it was showing 220F, to high for comfort.  Switched the fans on and it came down and settled at 180F on the probe and approx 210F on the gauge so my readings on the gauge seem to be around 25/30F too high.  

Any sources for the correct sender or do I need a resistor on the back of the gauge.

Horace

The Veglia water temperature gauge and the Ford  water temperate sending unit were never a correct match. I have never heard of anyone that has been able to locate the correct sending unit for the Veglia gauge that is used in a Pantera. I know someone that tried a Ferrari sending unit and it didn't work. The Ford dealers would sometimes install a resister in the line between the water temperature sending unit and the gauge and that would reduce the indicated gauge temperature. If you want to maintain the look of the Veglia water temperature and oil pressure gauge, there is a company in New Mexico that can install Stewart Warner gauge internals and a matched sending unit. I have a friend that did it to his Pantera and he is totally happy with the results. He has the original Veglia gauge look and with accurate readings.

FWIW, I installed the Pantera Electronics Temperature Gauge Compensator when I installed a 260-degree gauge in my Pantera. After installation, I periodically checked the coolant pressure tank temp until I was satisfied the gauge reading was accurate. I don't think Jon produces a compensator for the 230-degree gauge, though. 

Temp Gauge Compensator

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  • Temp Gauge Compensator

After years of trying to get this right I accomplished it successfully. 

Started with a system virtually full and went through all cooling system procedures again.  I've ran in some several mid 90 days here in Michigan and the guage reads about 192 consistantly.  This is using the Pantera-electronics compensator and a regular Ford sending unit from a 73 Mustang 351c 4v sending unit. 

Don't know what has made the difference this time, perhaps angle of the rear end raised but it had worked, even with the a/c running.

.Thanks for all the responses, much appreciated.

GOPR0026...First, Waterpump "REDUCTION" Pulley?? That would be a LARGER Pulley on the WP. If You have the SMALLER WP Pulley, That is a OVERDRIVE (by 11%) Pulley on the WP. If that is Your case...Leave it There! It is one of the Best Improvements You can do for the Cooling System.

You will have the Greatest Success, Bleeding Air, AT THE TOP CORNER of the RADIATOR! Leave the CAP On the TANK, Heat-Up and Pressurize the System, Loosen and remove the LITTLE SCREW at the Top, a Rush of Air will come out, like Your 'Filling a Tire', when Only Coolant Comes Out, Install the Screw Back in. Remove Cap at Tank and Top-Off Coolant. Ofcourse, Put the Cap Back-On and Take Car for a Drive, come Back Repeat if Necessary. If the system is NOT Boiling-Over into the Expansion Tank, there is No Problem, In My Opinion!

Read about My Exploits in the Desert, Last Summer, 90 MPH for Hours, 118F Degrees Ambient, I Didn't Have a Problem, I had the Sacc-Resto Overdrive Pulley on the Pump. The Highest the Veglia Gauge read was 189F.  'The Best by Test'!

Zoom-In on the Photo. This was a Stop at Idle, to take a Picture, Just on the Outskirts of Shoshone. At My right knee is the Temp Gauge with the Needle Pointing at 158F. Yes! It Is Reading Low! By Approximately 30F Degrees. That would put it at 188F. The Gauge has read Low since the Day I Purchased it and drove it Home.  I run a 180F RS Thermostat for 351C. Ambient Temp Here, 115F. We are Stopped Engine Idling. 3 Fans Going on the Rad, a Oil Cooler Fan Running at the Rear Grill.

MJ

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Last edited by marlinjack

Thanks for all the replys guys. 

I have contacted Jon at PE to ask if they do a compensator for the 230F gauge.

Marlin are you saying replace the stock WP pulley with the OD unit from someone like Ipsco.  I have the Flowcooler water pump fitted and there was a new core fitted in the rad last year.

I have bled the coolant system several times as you describe, doubt there is any air in the system now  though I am going to give the vacuum system a try now I have bought it.

No the system is not overheating but I would prefer all the gauges including the temp to give accurate readings.

Horace

FYI; the SACC water pump pulley is an overdrive pulley.

For those people who now have a vacuum filling device; it's not a bad idea to pull a vacuum in your cooling system, then leave it like that for a few hours before you fill the system with coolant. If the vacuum drops, you have an improper seal somewhere. It might be so minor that it probably wouldn't leak coolant but it's still worth investigating.   

Last edited by davidnunn

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