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Should I have to turn my electric fan on often?


olie05

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I run a themostatically controlled puller fan, and as stated by many it rarely comes on. Most of the time after the car is shut off. I have a second pusher fan wired to a dash switch, and it supplies peace of mind. If I am in stop and go traffic, I turn it on and feel better, and it is cheap insurance.

Bill

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I've heard about that optimum engine temperature for EFI before. And I've thought hard about it.

 

First: I got a carb. And a big motor where keeping it hot isn't a problem =)

 

Second: Engine temperature is controlled by the thermostat not by the temperature of water in your radiator. Thermostat reaches a certain temp and opens to allow the cooler water in the radiator to circulate. When it gets cool enough' date=' the thermostat closes again. The thermostat doesn't care what temperature the water from the radiator is. If anything the cooler water in the radiator will simply cause it to close sooner. Unless of course you have a hole drilled in the thermostat for constant circulation. You wouldn't do this if you had a problem keeping the motor warm, would you?

 

Driving your car at 40 mph in -10o weather with no fan at all will keep your radiator cooler than if you have an electric fan constantly running in the summer. But nobody warns you against this.

 

SO please tell me how my logic is wrong.

 

The constant draw on the alternator is a concern, but right now I have bigger fish to fry. I will eventualy get around to putting a thermostatic switch in.[/quote']

 

You live in Illinois, and you've never seen people put a piece of cardboard in front of the radiator? I've been running my truck with about 6 inches of radiator showing and it takes forever to warm up, but it will get there. I'm guessing that you might be 30 or 40 degrees colder than us in mid winter.

 

Here's how your logic is wrong. If you rely on the thermostat to regulate the engine temperature when it is 10º outside, then the engine is going to get to 195º and have a shot of -20º coolant blasted into it, then it will get back to 195, then get another shot of -20º coolant, then get hot again.

 

That couldn't possibly be good for any engine vs having a 30 or 40º difference in temps that you could get from blocking off the radiator. Ever heard that you should pour cold water on a hot engine? You're talking about injecting it INTO a hot engine. Seems back asswards to me.

 

Put a good temp gauge on your engine and you can watch the thermostat open and close in 80º weather, the temp swings down 20º then rises back up. I can only imagine what the temp swing is going to be in 10º weather. I'm sure the thermostat opens and the temp goes from 195º to 60º or something like that.

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You live in Illinois' date=' and you've never seen people put a piece of cardboard in front of the radiator? I've been running my truck with about 6 inches of radiator showing and it takes forever to warm up, but it will get there. I'm guessing that you might be 30 or 40 degrees colder than us in mid winter.

 

Here's how your logic is wrong. If you rely on the thermostat to regulate the engine temperature when it is 10º outside, then the engine is going to get to 195º and have a shot of -20º coolant blasted into it, then it will get back to 195, then get another shot of -20º coolant, then get hot again.

 

That couldn't possibly be good for any engine vs having a 30 or 40º difference in temps that you could get from blocking off the radiator. Ever heard that you should pour cold water on a hot engine? You're talking about injecting it INTO a hot engine. Seems back asswards to me.

 

Put a good temp gauge on your engine and you can watch the thermostat open and close in 80º weather, the temp swings down 20º then rises back up. I can only imagine what the temp swing is going to be in 10º weather. I'm sure the thermostat opens and the temp goes from 195º to 60º or something like that.[/quote']

 

I understand the point you are trying to make. However I don't think that the thermal shock is as severe as you are making it out to be. The cold water entering the engine also ends up mixing with some water that is already very warm. I live in a climate colder than both of you guys put together and I've never seen a engine cool off 135 degrees in a instant like you are suggesting. Maybe if you threw a hot engine into a cold swimming pool that would do it.

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Guest tony78_280z
You live in Illinois, and you've never seen people put a piece of cardboard in front of the radiator? I've been running my truck with about 6 inches of radiator showing and it takes forever to warm up, but it will get there. I'm guessing that you might be 30 or 40 degrees colder than us in mid winter.

 

Here's how your logic is wrong. If you rely on the thermostat to regulate the engine temperature when it is 10º outside, then the engine is going to get to 195º and have a shot of -20º coolant blasted into it, then it will get back to 195, then get another shot of -20º coolant, then get hot again

 

Every car ever manufactured (least all I've heard of) uses the thermostat to regulate engine temperature. Cardboard is not sold stock on any vehicle regardless of EFI or Carb or engine size and heat requirements. And in no owners manual does it tell you to put a piece of cardboard in front of your radiator to get it to optimum temperatures in the winter. If it was necessary for "Optimum Engine Operating Temperatures" It would be included. Although, putting cardboard in front of a rad does work, it is primarly used for vehicles with a problem warming up. Those with large radiators for summer workloads, or a stuck upen thermostat.

 

My sister, with the bran new saturn, runs her car at 40 mph down the road in -10o weather. She gets the same temperature shock blast each time the thermostat opens without the fan that my car would get with the fan. At 40mph the fan is going to make NO difference in the amount of air pushed through the radiator. Period.

 

I'm simply not buying into this cold shocking the system theory. And a fan can not ruin your "optimum operating temperature". Realy you don't need a fan over say 25 or 30 mph. Enough air is being pushed through the radiator at those speeds. Ever have your fan die on ya? Your good as long as you are moving. At a stop light, and watch that temp raise.

 

I doubt we get much colder than ya'll in Seatle. We are floating around 31-45 this week. Maybe your thermostat on your truck is sticking open. You should look into that.

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Every car ever manufactured (least all I've heard of) uses the thermostat to regulate engine temperature.

 

What about the old Volkswagons? :confused:

 

Seriously though, I don't think there is a need to argue here, I think the moral of the story should be that if you run a electric fan you should not "ghetto rig" your Z.. Control it with a thermostat, c'mon don't our Z's deserve better than that? If you need to drive it with the fan blasting all the time while you are waiting to get thermostat parts then fine, I'm sure it won't hurt anything. I remember last year when I pulled my Z out of storage the first place I drove it was to my buddy's place to fabricate a new exhaust. I had just put in a new rad and for some reason I can't remember I didn't have the fan. So I drove it without one.. It was still quite cool here and I knew that there was no way it was gonna overheat in a short trip. Of course I installed the fan while the exhaust was being done.

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question for you all. I just ordered a fan on ebay(taurus 2 speed) and I will get the thermostatic switch. My car has been heat soaking. If I let it sit for an hour after I drive it fine, if I let it sit for 5 min fine. But if I let it sit for 25 min then it starts up like crap and the temp is way up right after start up. So since I can't seem to find out why, I thought the electric fan would work. With that being said, the thermostatic switch is placed in the radiator fins. With the car off will this fluid raise in temp or is it fluid in the block that is getting hotter? I want the fan to come on for a few minutes after I stop the car like new cars. Also, with a stock 78 will the alternator hold up and for how long can the fan run after the car is turned off before the battery drains? I have a new radiator though and the car runs real cool when driving or in traffic.

 

Thanks all,

Kyle

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If your engine is fully warmed up when you shut it off, the temperature will RISE. This is normal as the water pump has stopped pushing the water. Ever noticed in a FWD car (most all of them have electric fans) that when you shut the car off you can hear the fan start up as you are walking away from the car. The electic fan will continue to run until the coolant in the rad is cooled back to a proper level. This usually only takes a minute.

In your case Innerware, I think your engine gets hotter after it sits a short time and gives you starting issues. A electic fan MAY solve this problem. Make sure you have the main feed for the fan coming from the battery and not from the ignition or accessory. This way your fan can run for a minute or two after you walk away from the car. As for your alternator, I think it will be fine. If your battery dies after a few minutes of running a electric fan then it's time to get a new battery anyway.

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Every car ever manufactured (least all I've heard of) uses the thermostat to regulate engine temperature. Cardboard is not sold stock on any vehicle regardless of EFI or Carb or engine size and heat requirements. And in no owners manual does it tell you to put a piece of cardboard in front of your radiator to get it to optimum temperatures in the winter. If it was necessary for "Optimum Engine Operating Temperatures" It would be included. Although' date=' putting cardboard in front of a rad does work, it is primarly used for vehicles with a problem warming up. Those with large radiators for summer workloads, or a stuck upen thermostat.

 

My sister, with the bran new saturn, runs her car at 40 mph down the road in -10o weather. She gets the same temperature shock blast each time the thermostat opens without the fan that my car would get with the fan. At 40mph the fan is going to make NO difference in the amount of air pushed through the radiator. Period.

 

I'm simply not buying into this cold shocking the system theory. And a fan can not ruin your "optimum operating temperature". Realy you don't need a fan over say 25 or 30 mph. Enough air is being pushed through the radiator at those speeds. Ever have your fan die on ya? Your good as long as you are moving. At a stop light, and watch that temp raise.

 

I doubt we get much colder than ya'll in Seatle. We are floating around 31-45 this week. Maybe your thermostat on your truck is sticking open. You should look into that.[/quote']

 

All of this is true. I have a brand new thermostat in my truck BTW.

 

All I can say is get a good temp gauge and you'll see the temp drop when the thermostat opens. And I wasn't kidding when I said I can see a 20º drop when it is 80 degrees outside and the thermostat opens. Carbed or FI, the engine is designed to run at a particular temp. You're right that cars don't come with an accessory option of a hunk of cardboard, but there is a reason why so many people do that. And aren't we all here because we know better than Nissan did in the first place???

 

EDIT-- One more thing. Don't we all pick a radiator that has a large enough capacity to cool our engine in the hottest weather it might see? Doesn't that lead you to believe that it might have too much capacity in the coldest weather you might see?

 

Technically you're right, but I'll keep my cardboard handy...

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Jon,

What brand of truck do you have? I used to have a 1970 Ford F100 that had a 302. When I replaced the thermostat I noticed that it had a bleed hole that allowed a small stream of coolant to flow even if the thermostat was closed, does yours have one of these? Maybe thats part of why it takes so long to warm up. That truck was the most cold blooded thing, took forever to warmup even in the summer.

I now have a 1988 Ranger which had a plugged radiator when I bought it. At first I didn't know this and took a 150 mile trip during the summer. It gets pretty hot in south eastern WA and I had to run the heater to prevent the thing from overheating, but the point I'm trying to get to is that when this happened it forced the thermostat into a locked open state and I had to replace it. I pretty sure thermostats are setup this way because the thermal properties of the spring changes when they get to hot and then they don't work as advertised.

You guys who are either not running a fan or manually control them may find that your thermostat gets put into the locked open position if the engine gets too hot but doesn't overheat. Just something to keep in mind when your engine won't warmup correctly.

 

Wheelman

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It's a Toyota with a 22RE, and it does have a bleed hole and a brand new radiator.

 

I've seen the thermostats that you're talking about that have like a barb on them so that if it gets over 220º or whatever it will be stuck full open. I think that is not the norm because I've never seen a factory stat set up like that, but I have seen them at the auto parts store.

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The ones I've had in both my Ford trucks have had those barbs. Of course I can't say whether they were OEM or not. I haven't pulled the stat in my LT1 yet but when I do to replace it with a 160 degree unit I'll see if it has them as well.

 

Wheelman

Don't forget, the LT1 takes a special thermostat :wink:

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Guest tony78_280z
Don't we all pick a radiator that has a large enough capacity to cool our engine in the hottest weather it might see?
I'm running the Z stock radiator. It's only 3 years old, but it's not the biggest and baddest. My temp stays at 195o in all weather. =)
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