Radiator fan engineering
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Radiator fan engineering
Recently I had a broken radiator hose on my 1984 5k and of course the engine became very hot. When I opened the hood I noticed that the radiator fan was not running. I found out from my Audi mechanic that the fan won't come on if there isn't water in the radiator. This seems like dumb engineering to me. I need the fan to cool the engine even if my coolant is low. Are other cars designed the same way? My mechanic told me next time to turn the A/C on and that will force the fan to run. Well, that's great if your A/C compressor happens to work, which mine doesn't at the present time.
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It doesn't matter if your A/C compressor...
..works or not. When you turn your A/C on it will activate the fan for the evaporator. It runs all the time for the evaporator regardless if it need to or not!!
You're just not going to get any cold air though...oh well!!
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Andrew
95 90Q
91 90
You're just not going to get any cold air though...oh well!!
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Andrew
95 90Q
91 90
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Without coolant traveling through the engine, I don't think...
...the fan could cool things off efficiently enough to do any good anyway. You really need the internal cooling from the coolant coming from the radiator.<p>Charles
2000 Nissan Xterra SE V6 4x4
'98 A4 2.8 Q-Tip (employer owned)
2000 Nissan Xterra SE V6 4x4
'98 A4 2.8 Q-Tip (employer owned)
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From: Dallas TX
Re: It doesn't matter if your A/C compressor...
Andrew, you are referring to the condenser unit, right in front of the radiator, which needs the constant air flow and the reason why the fan motor always runs when the a/c circuit is energized. The evaporator is in the black box under the black plastic cover behind the firewall on the p/s.
You are correct about the compressor, just to check, I disconnected the electrical connector to the clutch and turned on the system, fan still came on at slow speed. This is a good check to determine if the fan motor or temp sender is bad in an overheating situation, assuming you did not loose coolant.
Ken, this coolant temp sender is below the lower radiator hose and energizes the fan when the coolant reaches a pre-set temp. With no coolant in the radiator, the sender cannot close the circuit and energize the fan.
hth
Tom Serrago
85 5KS Avant
99.5 A4 tqms
You are correct about the compressor, just to check, I disconnected the electrical connector to the clutch and turned on the system, fan still came on at slow speed. This is a good check to determine if the fan motor or temp sender is bad in an overheating situation, assuming you did not loose coolant.
Ken, this coolant temp sender is below the lower radiator hose and energizes the fan when the coolant reaches a pre-set temp. With no coolant in the radiator, the sender cannot close the circuit and energize the fan.
hth
Tom Serrago
85 5KS Avant
99.5 A4 tqms
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Yeah Tom....
..Thanks for pointing that out. I just wrote the wrong thing, my fault. Like Tom pointed out I meant the condensor, and not the evaporator!! I guess I should take more time to proof read when writing responses!
Thanks for correcting me Tom.
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Andrew
95 90Q
91 90
Thanks for correcting me Tom.
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Andrew
95 90Q
91 90
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Re: Radiator fan engineering
I got to thinking about this problem after I wrote the message. I guess it only makes sense that the fan really doesn't have anything to cool down if there isn't any water in the radiator because it is mostly the water that facilitates the cooling of the engine (unless you have a VW).
I had to drive my 1984 5K about 5 miles to the mechanic without much (or any) coolant in the radiator. I drove it as fast as I could (also watching for cops) until I got there. The temp gauge was at the half-way mark until I got within a half mile of the shop and then it went to 3/4 hot. I got caught by a couple of traffic lights, so I had to slow down. Fortunately I made it there without a problems. So, I guess Audi's can be air-cooled too (at least over 40 m.p.h.).
I had to drive my 1984 5K about 5 miles to the mechanic without much (or any) coolant in the radiator. I drove it as fast as I could (also watching for cops) until I got there. The temp gauge was at the half-way mark until I got within a half mile of the shop and then it went to 3/4 hot. I got caught by a couple of traffic lights, so I had to slow down. Fortunately I made it there without a problems. So, I guess Audi's can be air-cooled too (at least over 40 m.p.h.).
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my radiator fan will not stop spinning
My 1985 audi coupe recentley started to over heat so i decided to replace the water pump, thurmostat, and hoses. It was running fine but all of a sudden my radiator fan will not stop working even after i turn the car of and remove the keys from the ignition. I thought it was normal, but it drained my battery that night. Now every time i stop the car i have to disconect it and it is a huge pain. Can anyone help?
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