overheating

[CC'S95GT]

If the rad cap isn't holding pressure then it'll run hotter too. maybe not to the point of overheating

 

[toyman]

LOL. Rethink this statement, it is absolutely not BS. A radiator, or heating/cooling coil's ability to gain heat (or loose it), all depends on the velocity of the coolant. Read up on hydronics, system balancing to be specific. A thermostat makes that flow restriction.

I do not need to rethink the statement as it's absolutely true. Coolant rate of flow is not the determining factor. Rather it's the radiators capacity to transfer heat to the air flowing through the rad. The T-stat in this case allows the engine to come up to operating temperature more quickly than if it wasn't there. Look at the flow this way.In a closed loop, a given water molecule actually spends the same amount of time in the radiator, no matter how fast it is moving, as long as the water is indeed moving. If this is a difficult concept to understand, think about a race car on a track. If the track is one mile (5280 ft) long and the car is driving at 60 mph, the car will spend about one second in a 100 ft stretch. Think of the 100 ft stretch as the radiator. If the speed is doubled, the car only spends ½ a second in the 100 ft section, but it passes through that same section twice a minute, so it spends a total of one second in the 100 ft section per minute.

However, you are entitled to your position.

 

[RichV]

How did you come to that example?

I deal with hydronics in HVAC systems daily. Same rules apply here. If you look at a thermostat, it only allows like 25% of the line flow. It is a restriction and I'm pretty sure it was designed by someone smarter than both of us.

Also running my race car without a thermostat at high rpm caused it to heat up about 3/4 of the race. With thermostat it does much better. So that's my real word experience.

 

[RichV]

Wait, I have a goofy example...

If you run a mile then run into a air conditioned house, would your body cool off faster if you ran through the house at full speed, or slower?

 

[toyman]

We are talking about a closed loop system. Running through a house doesn't meet the criteria. Balancing the hydronics in HVAC system is a different matter. The fact is an engine will generate a certain amount of heat at any given load. The function of the radiator is to dissipate that heat. If the radiator can transfer the heat out faster than the engine can create it, yes the t-stat will start to close to reduce the flow to maintain the desired engine operating temperature. You are making the assumption that the reduced flow is what is cooling the engine when in fact it is the reduced flow through the t-stat that is allowing the engine to move back up to it's design temperature. And I would not assume that someone smarter than us designed the system but rather someone whose area of engineering knowledge extends into an area where our knowledge is limited.

So, I'll ask you, why is there a need for extra cooling capacity radiators and high flow water pumps if all you have to do is slow the water flow through the radiator for better cooling?

 

[CC'S95GT]

because it's a balancing act. the larger radiators and high flow water pumps are used on cars that produce more heat than the stock system can remove. Ie: turbo, superchargers, and larger displacement engines and tow rigs.
Actually the example above is pretty much right on.

 

[RichV]

OK, I kinda see your point.

Like CC said, it's a balance of everything. All your components have to be sized adequately. If the engine is making so much heat that the radiator can't dissapate it, it does not matter how fast or slow the water moves, it will not cool. It needs to be sized right. This scenario isn't anything abnormal, it's simply a stock motor that can't cool itself. So either there is too much heat being created, ie HG failure, or there is a flow issue, too much or not enough of water or air.

HVAC systems closed loop as well. Only difference is you want the coils to add or remove heat into the airstream that is being created for that purpose.

 

[97FloridaGT]

Wow, you guys just automatically assume the worse. Start out small and simple. How does your coolant look? Is it green and clean or is it dirty and muddy looking? How is the rubber seal in the radiator cap? Does it still look plush and able to do its job, or is it worn and leaking? A new cap is cheap insurance and it probably needs done anyways, so spend the couple bucks and buy on. Do NOT get a "lever cap" and make absolutely sure that it is the stock PSI rating. Do you know anyone with a laser thermometer? If you do, start the car and let it warm up then aim the thermometer in a few different places if the radiator. Also, put the t-stat back in....nothing special, just a stocker, and TEST it. I've been burned too many times with a bad t stat that I test them as soon as I get home. A pot of boiling water and a meat thermometer is your friend here. Lastly, check the fan's operation. Get the car warmed up and make sure everything is working good. If not, check for power at the fan plug using a test light or a multimeter. If you ARE, then your fan motor is bad and you need to swap in a T-Bird fan. (3000cfm ftmfw!) If you AREN'T getting power to the fan, check that you're getting power to the relay and if you are than chances are, it's a bad relay. Always use the KISS method and good luck.

 

[drewski92]

the car overheats in the cold still.. it was my waterpump but now with the thermostat out and a new waterpump the car still runs hot. it gets between halfway and hot. i have no idea what else it could be.

 

[rz5.0]

Put the termostat back in.

 

[Raffaelli]

I've replaced everything trying to get my 94 to run cool. Radiator, wp. T stat. New fans wired up consistantly on. Ect.

My timing cover was pitted in the waterpump backing part. Causing my coolant to aireate.

I've also smoked my rings and had to rebuild my motor because of a bad fan electrical connection.

I've had the worst luck with cooling in that car