Anyone had Success with Auxiliary Fan?

[Snibbor]

Was wondering if anyone has had success with an Auxiliary Fan in helping cool down the radiator?

[TJ Hopland]

It depends on when and what problem you are trying to solve. If its underway or in traffic I would say no, you need to figure out what the real issue is and solve that. 

If your problem is hot restarts then ya maybe. Before I went EFI on my 73 Eldo I ran an electric fan in front of the radiator tied to a mechanical wind up timer.  I would set it for 10 mins or so anytime I shut the car off and that solved my restart issues. 

I found that was my issue because I could actually hear and if I opened the hood see the fuel boiling out of the carb when shut it off.  While trying to observe that one time I opened the hood before I shut the engine off and it didn't do it.  Turned out opening the hood let enough air flow that it just barely kept the temps below the boiling point.  That got me thinking that maybe I just needed to move a little air and that's all it took. 

My problem only happened if I ran gas with ethanol in it but at the time I didn't have any practical options to not run ethanol so I had to find a way to work with it.  Back then I didn't have working AC either so the condenser wasn't there to add heat or slow down the airflow.

[Snibbor]

OK. My '67 overheats slowly as I drive and does so increasingly when I idle. So I thought and electric fan might help mitigate the overheating somewhat...

[The Tassie Devil(le)]

Me thinks you should invest in an aftermarket gauge and plumb it in and read what the actual temperatures are getting to.

It is a simple task to fit an electric gauge, and run the wire through a suitable area in the firewall without having to drill any holes, and observe the readings whilst seated behind the wheel.

If the actual temperature is slowly climbing and climbing and not stabilising, then I would be looking for some sort of blockage, in the coolant flow, be it a collapsing bottom radiator hose or a faulty thermostat.

Bruce.

[TJ Hopland]

Ya I would be going through everything.  If you go electric you can't just slap one up front and call it good.  It would be a custom job where someone has to design the whole system with the fans, shroud, and likely bypass flaps.  You would also likely end up needing to upgrade the alternator and regulator which would require at least some wiring upgrades so its really not a simple or cheap change.  Since you didn't deal with the original problem it may not have gained you anything either.   

[dn010]

On my 1957, I removed the mechanical water pump mounted fan and installed on the outside of the radiator a 16" 3500 CFM electric fan controlled by radiator probe. I have an alternator, no shroud, and the air it moves is amazing compared to stock. I don't have AC (condenser) to require or hinder air flow so that would have been a challenge to overcome. Extended idling or any engine labor, my gauge will not go past half in the hot Florida weather, so these fans do work. But I'm also running a recored radiator, engine rebuilt (flushed/cleaned) and hoses/lines all new. I didn't dump the original fan due to problems, I did it so I had fewer moving parts stressing the water pump and peace of mind knowing the fan is more than capable of cooling.

However, like the rest of the posts here suggest, you're seeking a bandaid for a more serious problem. I would not stick a fan on it and hope for the best. You have an issue you need to take time to diagnose. Could be anything from a pinhole leak in a hose somewhere that you just don't see while diving, to sludge built up on your cylinders in your water jacket. Has the system been flushed? What came out if so? Can you see any chunks when your radiator is low? Have you or your mechanic put a pressure tester on the radiator? How long did it hold pressure for? etc. etc.

Can you tell what color the coolant is in the radiator after it has run?

[Snibbor]

Bruce,

It is in fact a slow progression upward (temp-wise). But looking in the radiator the "flow" looks good. But that would not rule out a blockage huh?

[V63]

Also verify your timing (too far retarded) and VACUUM leaks. Lein mixture equals over heating. Bypass All body vacuum circuits for diagnosis, check vacuum advance.

[Jeff Rosansky CLC #28373]

One thing I will ask on electric fan questions is; how are you defining hot? A lot of people are trying to fix something that isn't broken because they want these to run at 180. That just isn't realistic.
Just pointing that out.
Jeff R

[dn010]

James has another thread where he is actually overheating and "spewing coolant." That thread ends by saying the problem was the clutch fan, so I'm guessing that didn't exactly fix his issue.
https://forums.cadillaclasalleclub.org/index.php?topic=168556.0

One thing I will ask on electric fan questions is; how are you defining hot? A lot of people are trying to fix something that isn't broken because they want these to run at 180. That just isn't realistic.
Just pointing that out.
Jeff R

[bcroe]

The plan here is to go with a fully equipped late 70s style cooling system, big fan with shroud, coolant recovery, radiator size upgrade.  Yes temp gauge is a must.  Some think it is OK if the temp wanders around, but that just tells me it is out of control.  Mine stay anchored at whatever the thermostat is. 

That might be enough, I have used a pair of electric fans in the front.  Wire them in series or parallel for 2 speeds.  The AC condensor up front might got hot in slow traffic and no fan, so a sensor detects this and runs the fans half speed.  An increasing engine temp does the same.  If the engine gets hotter yet, they run at max, and will continue in this mode after shutdown, until the engine cools some.  I never expect an electric fan to replace the belt driven fan, since it could never generate the 5hp of the latter.   Bruce Roe 

[Snibbor]

Thanks for all the input. I am putting the new fan clutch in next week but anticipating it not solving the slow temp progression problem. If it does not I will look towards the vacuum issues and timing...I HOPE the fan clutch is the fix.

[The Tassie Devil(le)]

James,

You have to remember that with any car cooling system, with the conventional system with the radiator mounted in front, when driving at any speed above around 35 MPH there is sufficient air flowing through the grille and radiator to maintain the correct temperature.   The Fan is only there to maintain air flow when driving less than 35 MPH, as in slow traffic and stop/start motoring, plus when following too close to another vehicle, as in the slipstream.

I have proved this many times with my Hot Rods.

Bruce.

PS.   The Water Pump is there to move the coolant through the radiator, and the makers found it convenient to install the fan on the end of the pump.

[E Masters]

On my 67 I found the heat would increase with speed. After many years I noticed in the workshop manual a picture of the thermostat. It had a wide opening which was larger than the standard ones. I checked out some high flow ones but they still had a small opening. After finding a large opening thermostat the issue was resolved.

[TJ Hopland]

You also need to make sure that all of the little deflectors and flaps are still in place around the front of the car.  I don't know what a 67 was supposed to have but by the early 70's there were like 7 different rubber flaps around various places under the hood and radiator.   Just one of those missing could change the way the air flows and be causing the issues. 

[Snibbor]

TJ Hopland, Can you be more specific about the "rubber flaps" you are referring to??

[TJ Hopland]

I don't know about a 67 but a few years later there were several different rubber like pieces in various places under the hood.  I originally thought they were just splash guards to keep water from getting on the engine.  Over the years they get removed and not reinstalled as a result of other repairs or they just rot out and fall off.

These flaps are in various places like between the bumper and radiator.  Sides of the radiator and condenser.  Above the control arms where they poke through the wheel wells.  Some cars also have one that just hangs down in the front.  You also want to make sure your hood is dropping down all the way so its sealing in the cowl area.  All these seemingly little things all add up to how all the air flows in and around the engine especially at highway speeds.   

[Snibbor]

TJ, I had not really though about that. Good information.