Fan Clutch

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NicolasB
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Re: Fan Clutch

Postby NicolasB » Tue Mar 09, 2021 7:44 pm

Ah okay, then the previous owners changed it in the past to a non-thermal since mine has A/C (even though it doesn’t work now). I’m honestly not sure what GM installed on these from the factory, maybe the Chassis Service Manual provides some insight. The reason I asked about this is because I had to wait in traffic for a bit more than an hour on a day where the temperature was about 58 degrees F and the temperature gauge rose to 235-240 degrees F. The car started to surge and sputter so I turned it off for a bit to let it cool. Now this happened a few days ago and haven’t been in the same scenario since, but so far I replaced the clutch, added more coolant, and checked the water pump (it still works). I haven’t changed the coolant yet but I will when I have the chance and try to use those additives that clean the inside of the radiator from rust and dirt.

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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Tue Mar 09, 2021 9:22 pm

If the old clutch wasn't engaging, it very well could start overheating in traffic, even on a cold day.

For future reference if that ever happens again, turn your heater on full blast. Since the heater core is basically just a smaller radiator, the heater fan blows cold air across it to remove heat from the water and heat the car. It won't be comfortable but you'll see the gauge drop.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Wed Mar 10, 2021 1:20 pm

Only if my heater was working haha. Before I took out the instrument panel the blower motors and heater worked, but after putting it back in they both stopped working. The chassis service manual doesn’t help since the heater/AC unit they have in the diagram is different from mine. I also asked the forum a couple months back but it seems like no one was able to figure out the issue.

Direct wire it to the battery and see if it works. If it does, just trace all the wiring. Probably a broken/brittle wire or bad connction.

orphage
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1986 Oldsmobile Firenza Coupe
2004 Jaguar Vanden Plas

Re: Fan Clutch

Postby orphage » Fri Mar 12, 2021 9:46 pm

You should have a thermal fan clutch. My 69 Toro is a non A/C but has HD cooling and shows the correct OY code as per the service manual :

69 Service Manual page 6K-8.jpg
69 Service Manual page 6K-8.jpg (89.17 KiB) Viewed 16705 times


Here's a picture of my fan clutch:

OY Fan Clutch.jpg
OY Fan Clutch.jpg (392.5 KiB) Viewed 16705 times

Schurkey
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Re: Fan Clutch

Postby Schurkey » Thu Mar 18, 2021 6:30 pm

To my knowledge, NO OEM ever used a non-thermal fan clutch. The non-thermal clutches are strictly an aftermarket "cheapskate" option; for folks who won't spend the money to fix it "right".

There's a thousand reasons an engine might overheat at idle. Lack of airflow through the radiator, and lack of spark advance being two common ones, but certainly not the only reasons.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Wed Mar 31, 2021 9:13 am

Update: So I did a radiator flush yesterday on the Toro and the coolant was pretty bad. I used two bottles of Prestone Flush Plus Cleaner to remove some of the crud that is in the system. I know it’s not going to completely resolve the issue since the radiator is pretty rusted inside, but should improve the cooling temperatures. I haven’t driven it in the day or in traffic yet, but after driving it for 100 miles last night I did notice an improvement in that area. Before the flush, the gauge would read about 210 degrees Fahrenheit when driving at night at around 65-70 mph, and now it reads 200 when I go 70-80 mph. At 65 it would stay around 190-200. Now to truly test it I would need to drive in traffic during the day.

Did I have to turn on the heater when I did the flush? The heater and blower motors don’t work so I didn’t have much of a choice.
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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Wed Mar 31, 2021 10:46 am

Normally you want to clean out the heater core, too. You can disconnect the heater hoses at the core and blow out the core with air and/or flush with a garden hose.

NicolasB
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Re: Fan Clutch

Postby NicolasB » Wed Mar 31, 2021 1:25 pm

In that case would I have to drain the coolant again if I flush the heater core alone?

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Otto Skorzeny
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Re: Fan Clutch

Postby Otto Skorzeny » Wed Mar 31, 2021 4:29 pm

No. You can clean it out and flush it independently of the engine. You can disconnect the heater hoses at the heater core and connect them to each other and bypass the core altogether. If you think there's crap in the core that's going to contaminate the water in the block then you should do that anyway.

NicolasB
Posts: 261
Joined: Sat Apr 25, 2020 9:27 pm
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Years Owned: 1969 Oldsmobile Toronado

Re: Fan Clutch

Postby NicolasB » Wed Mar 31, 2021 6:23 pm

Ah okay, I’ll try to do that. I took it out right now on the streets and the temperature went up to 205 degrees. Is that fine? It’s 87 degrees where I am and drove it for twenty minutes. While I did that I drove to PepBoys to check their electric fans, but the smallest size (10”) doesn’t fit in front of the radiator. I want to get some extra cooling to be safe, but want to keep the clutch fan as a backup (my dad did that with his ‘66 F-85 and it works perfectly). There are smaller sizes (6”-8”), but am not sure if they would fit. If room allows, could it be possible to install one in the back of the radiator while keeping the clutch fan or is that a bad idea? I’ve talked to my dad about it and he’s saying to just go all electric.


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