308 radiator fan question

Depends - are you flying down the highway at 90 mph, or are you in stop-and-go traffic?

When my fans stopped running (loose wire connection to the radiator thermo switch), my temps would rise as the car slowed. Many times, the temps would almost peg the meter and the car would need to be shut down.

High speeds compensate for problems in the cooling system - speed dumps lots of air through the radiator and into the engine compartment, so I'd never see problems until I stopped for a red light or heavy traffic.

 

if the fans don't turn on by 220 or 230 degrees turn off the engine and fix the fans. put a jumper across the thermal switch at the right bottom of the radiator to start, bad switch very common. see vw replacement part in prev thread by the esteemed dr. tommy. o/w you'll need to start with fuses and then check continuity. unlikely both fans are bad. good luck jon s.
p.s. unlikely to warp heads if engine is at idle but if you get it really hot you're pushing your luck.

 

I think you would probably run into problems in fairly short order. You should be able to run it at freeway speeds for a while but as soon as you stop, the temp will start climbing. In my experience with most cars, once you hit the upper regions of water temp, things can go bad pretty quickly. I don't see any way that just the pump and radiator could keep up unless it's very cold outside.

My short answer to your questions is: I personally wouldn't drive a 308 very far in traffic without having functioning fans.


I can tell you though that if your car won't run, even in very hot weather, without overheating there is a problem. After re-doing my water pump my car now runs prefectly within temps. Took a three day trip recently and drove through at least half of the first day in 100+ degree temps. The car never overheated or puked any coolant. Perfect.

 

In 80 degree weather, my fans stay off while I'm moving at 10-15 mph. However, once I've been driving for 10-15 minuites, I hear the fans come on well before lights change. I suspect that w/o them the engine would overheat in stopNgo traffic, & am not sure it would recover enough between lights to keep from overheating.

In 90+ degree weather I'm fairly confident that it wouldn't recover between lights, & would slowly creep into overheating.

Haven't noticed them coming on on highway at 40=70mph, but also haven't done much long distance in 90+ degree weather.

In 50 degree weather, I don't remember ever hearing them come on.

 

I can also tell you that in 80+ degree conditions cruising at or above triple digits the heat will climb to the point that (I hope) the fans will come on. I really couldn't tell because it also gets a little noisy at that speed in a GTS with the top off!!

 

fans do little at speeds above 15 to 20 mph (I have seen some studies at 35mph depending on the air intake size) since the intake air is now more than the fans would push, I wouldn't pull out of the garage, even in winter, w/o BOTH fans working, infact I am going to upgrade to Hayden's and a alum rad and vw switch later this summer just to ease the stress on me worrying about the fans

 

robert: my fans never turn on below 200 but they do keep the temp from rising much above that at idle or heavy traffic crawl. when i bought the car the thermal switch was dead and the previous wholesaler/dealer had jumped the switch so the fans ran whenever the engine was on. i replaced the switch and also put a rocker switch in parallel under the dash so i could turn on the fans regardless. as always if you fry the heads in slow trafffic you become very sad . good luck jon s.

 

In that situation, you will need the fans, no question.

 

I was working on an A/C wiring problem on my 308 today and noticed that the RH fan is always on when the A/C is on.

So if you suspect the fans aren't working and the car is overheating, a quick fix to get you home could be to turn on the A/C at minimum temperature. This should turn on one fan independent of the thermal switch but keep the A/C compressor from cycling.

Of course the other choice is to use the two other radiaters (heater cores actually). Turning on the heat to them and using the ventilation fan will get you toasty, but can drop the water temperature by quite a bit. Your choice, hot toes or an overheated engine.

Regards, Kerry

 

They are MANDATORY if you are sitting still. They are just there to blow air thru the radiator when you are not DRIVING THRU the air.

 

dr. tom: speaking of radiator fans, did you ever do the rewire so both fans go on with the a.c.? jon s.

 

I have always carried a couple "jumpers" made from 12 ga wire (about 4 inches long) with male spade terminals on each end. You can use these to jump the thermo switch on the radiator and leave both fans always running. It has literally saved three different people on various Ferrari group trips I have been on. I have never needed them myself, but always carry them...and have even given them out to others, "just in case".

 

I noticed this as well and made a fix for it. I bought a nice new temp switch, and soldered 12" "pigtail" wires to it, then put connectors on the pigtails to connect to the wiring harness. Now the connectors are tucked up out of the way where they are not exposed to as much heat to oxidize them and the actual connection to the thermoswitch is soldered. Haven't had a problem since.

Like Dave, I also carry a "jumper" for emergencies!

Birdman

 

i have the autozone 180 switch. see the parts thread i started for all of the switch numbers and decide which one you want. the 160 VW switch is supposed to be the best, but the fans will run all the time. this may be of a concern if you do not have Birdmans new fuseblocks. the constant draw on the older fuseblocks may cause a fire or other problems. my fans are always on at 180, i can hear the relay click on and off when i am not making noise with the right pedal.

gt4 runs much cooler, it appears to have the VW 160 switch, but the gt4 also has the wide opening in the front hood which MUST provide better cooling than the old style GTB bonnet.

 

please understand i am no expert, but 2 out of 3 308's i have owned have had cracked and partly melted fuseblocks. the GTBs original blocks had heat damage at the headlights, a/c fuse and the L/R radiator fan fuses. its just my opinion that the cooler switch "may" cause a problem with a higher, constant amp load. perhaps one of the ferrari techs ( the um real mechanics) can help better explain this.

i hate fire, and i would not want to cause you to burn up your car. i think the Dino has a VW switch in it though, as the fans kick on really early and the car stays very cool, even in the current Georgia 100+ heat and humidity.
my Dino has the orginal blocks, and everything seems to work ok, for now.

feel free to pm me if you need any more help, as i have had both current cars apart and back together a few times . Michael

 

I have the VW switch ( I own 3 sciroccos ) and my fans don't run all the time. It works fine in my car and has for nearly 8 years.

By the way, it's not really a "VW" switch exactly. It's just the same one they use too. My 82 Alfa Spider has one also so if VW bothers anyone just call it an Alfa Romeo fan switch if you want.

 

If you're worried about your stock fuse block, here's a temporary fix that will improve it's connectivity for quite a while:

Remove the fuse block & tighten up all of the rivits by backing them up with something hard & flat, & tapping the other end with a punch that's the same diameter as the rivit, or slightly larger.

The impact will break thru the built-up oxide in the connections & it will take it quite a while to re-form.

As long as your contacts haven't been over-heated & weakened, a permanent fix is to solder the rivits as is described in the old fchat archives. Just search body of posts for:
[ solder fuse block ]

Of you can buy a Birdman Block...

 

good to know. i killed both of my cooling fans today on the GTB. now i am looking for Sparco / Lucas fan blades. the motors are fine, the blades are ferrari part # 110916. started another thread...