Fan Clutch

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NicolasB
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Re: Fan Clutch

Postby NicolasB » Tue Jun 29, 2021 6:10 pm

Update: So I was able to get the radiator fixed and cleaned at a shop and got a new lower radiator hose, as well as two dual 12” electric fans as pushers, installed. I’m still having an issue with overheating regardless. When I drive uphill for several minutes I can see the temp gauge climbing and reach 230 degrees, even with the fans on. It only cools down if I coast downhill. The electric fans are 1650 cfm each. I burped the system, but still didn’t help. I also checked the thermostat and it works. Any suggestions?

Note: Outside temperature is 90 degrees today.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Tue Jun 29, 2021 6:16 pm

I just opened the vent on the radiator cap and coolant and air went into the overflow tank. So does that mean that there’s still air in the system? The cap is rated at 16 psi.

Schurkey
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Re: Fan Clutch

Postby Schurkey » Tue Jun 29, 2021 8:38 pm

NicolasB wrote:I just opened the vent on the radiator cap and coolant and air went into the overflow tank. So does that mean that there’s still air in the system? The cap is rated at 16 psi.

Some possibilities:
1. Residual air from the recent cooling system work.

2. Combustion chamber pressure leaking from the cylinder to the water jacket via a cracked casting or failed head gasket.

3. Leak in radiator, failed rad cap seal, cracked or improperly-clamped hose from overflow tank to radiator. Air is coming into the radiator when the vehicle cools off.

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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Wed Jun 30, 2021 4:59 am

When you opened the cap, was the engine cold or hot?

If it was hot, the coolant probably just turned into steam after the release of pressure.

The boiling point of your coolant increases 3 degrees for every pound of pressure. That means the water in your radiator could be 260 degrees.

Does the overflow reservoir level rise when the engine is hot and come back to the original level when cold? Are you experiencing a loss of coolant?

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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Wed Jun 30, 2021 5:07 am

230 degrees isn't unusual or detrimental.

Does the car exhibit driveability problems when the temp climbs to that level? If not, I wouldn't worry about it.

My '72 Monte Carlo used to run at about 230 degrees all the time. When I took steps that lowered the operating temperature, it started running like crap. It just ran best at that high temp.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Wed Jun 30, 2021 8:59 am

The only way for the overflow tank to rise is if I open the vent in the radiator cap. After that, it typically lowers when the temp drops. If it goes above 215, the car feels like it loses power and gets a bit sluggish. Anything above 225 would make it feels rough and want to stall. It seems like the sweet spot for it is between 180-215.

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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Wed Jun 30, 2021 12:50 pm

Either you have the wrong type or broken radiator cap, or the cooling system is venting somewhere else and drawing air in.

When the engine is hot that tank should rise an inch or two. Make sure the overflow tube isn't clogged and that its tight on the filler neck nipple.

Make sure your cap has this poppet valve and two seals - one for the top of the filler neck and one that seals the radiator form the overflow tube.
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NicolasB
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Re: Fan Clutch

Postby NicolasB » Wed Jun 30, 2021 6:38 pm

So I was able to talk on the phone with our mechanic and he said that it’s mostly likely not the head gasket, but could possibly be that there is some type of blockage somewhere in the engine, like around the freeze plugs (or that the freeze plugs are bad). I’m going to take it to him on Friday so he can see the issue in person. Hopefully the fix is not that complicated.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Thu Jul 15, 2021 12:45 am

Quick question, I checked the thermostat and it’s a 160 degree one. Should I opt for a higher temp one? I heard that too cool of a thermostat can actually make the car overheat more easily.

Tuco
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Re: Fan Clutch

Postby Tuco » Thu Jul 15, 2021 6:10 am

I normally use a 180 thermostat. The theory is that a cooler thermostat allows water to flow faster thru the radiator before it has a chance to cool. When we were kids we would take the thermostat out of an overheating engine thinking that would cool it faster but it was actually was creating a bigger problem. There has to be some resistance.


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