F355 Cooling Fan Issue

I don't know if it's normal or not but mine does the same thing? Once to temp. on for a few sec. (not sure how many) then off for a few then right back on over and over till I'm moving and its getting air. My car has never overheated and I drive it with the a/c on in 110+ degree weather. I just thought it was normal.

 

I believe this is normal. Mine does it as well. I asked a local Ferrari mechanic and was told it was normal.

 

Perfectly normal----mine does the same thing....

 

Brendan - this is not normal. I had this problem as well. My LH fan would cycle on and off too quickly, and my RH fan had a mind of its own. It would decide for itself when it wanted to cycle on and off. In traffic I would run hot, but once I started moving, things would cool down.

Now my car is normal. When my fans come on, they stay on until the proper temp is achieved. It's a matter of time until you're stuck in beltway traffic and you start running hot, and you got no where to drive to cool things down.

Simple + cheap fix, and trust me, if i can do it so can you.

Here are some instructions on changing it.
http://www.ferrarichat.com/forum/sho...nt+temp+sensor

The part you need for RH fan is:
http://www.ricambiamerica.com/advanced_search_result.php?keywords=125769

Piece of cake. While you're at it make sure your LH fan is coming on and off properly. Good Luck.

Bobby

 

Going on and off is normal ....... going over 190 is not ............ replace the thermal switch on top of the LH radiator ...... that is what triggers when the fan sould come on and off ........... it seems the rest of the circuit is fine. They are cheap insurance and available through Ricambi ............. !

http://www.ricambiamerica.com/product_info.php?products_id=203958

 

Yeah, your post was too long ........... .................... use redline water wetter ............ that will improve cooling efficiency ........ and keep it from going over 190.

 

My driver's side was not coming on at all awhile back----replaced the temp sensor at top of driver's side radiator. Now it comes on and off and cycles like you are describing. My mechanic said this is normal and as long as it is working and cycling it is fine. My temp does not go over 190.... Sounds like you checked everything and replaced what needed replaced. Not much else to the system to check or replace. Fan, hoses, relays, fuses, sensors--If they all check good and the car does not get above 190---Why are you still considering a problem?

 

I have a 348, so not totally familiar with your 355. But IIRC, on the 348 the temp gauge sensor is on top of the engine, so it's measuring engine temp (which is what you want to read), and not on the radiator. So if you're looking for 180 deg. on your dash gauge, it may not read 180deg. when your radiator itself reaches 180deg and shuts off. Just thinking this may be part of what you're looking for.

 

+1 ........ well said ......... the thermal switch is in a different location than the water temp gauge sensor ......

 

The manual is not the best to go by--Lot of errors in that thing....I trust the judgement of guys here before the manual any day of the week..

 

The 355 has 2 water temp switches 1 on top of the left rad and 1 near the oil filter on the cross over tube. The 1 on the LH rad is for that fan on that side, the signal from the 1 on the engine goes to the ECU than to the RH fan. Try adding some fluid to your over flow tank(sometimes the level can look deceiving and be a little low), the sensor on the LH rad is at the top of the system may not be reading(ie; because it is low) the coolant properly. Even if the tank looks full try a quart at first, gravity will sometimes do its thing and the system will take the fluid and cover the sensor.
Also the system on the 355 is self bleeding so the air problem should not be a problem, especially since you changed the small hoses. You should use a silicon hose for those 2 anyway you will need to replace them often if you don't.

 

Am I right in thinking the fans also run to cool the A/C Condenser? if so I suspect it's the pressure switch on this system causing the cycling ie on/ off for short periods.

 

+10-----Dave helms sells the small ones in MilSpec silicone

 

I think that these cooling fans should be on all the time to help cooling the engine. The 355 engine generates so much heat around the radiators that if these cooling fans were on all the time the benefits will surpass the expenses of changing cooling fans every 2-3 years. I would say that if you upgrade the battery to a higher current battery and find a good quality fan that can run all the time, most of the other issues of heat will be resolved.

 

Actually, if the fans ran all the time, you would need to have a higher output alternator, basically upgraded per the Ernie and other threads started here. But fans running constantly would be annoyingly loud, and completely unnecessary while underway beyond 30mph.

 

BUMP

My fans work exactly like the OP stated. After 12 years, is there absolute consensus that this is normal? The replies suggest that this is the proper behavior, but clearly, this is contrary to what the WSM states:

Does anyone have a car where the LH fan cycles between 190 and 180, and the RH fan comes on at 203'.?

 

There are too many variables to make a judgement. Did the OP have his airconditioning on? It was summer.

Do you mean gauge readings or temperatures at the sensors (which most people are not looking at)?

 

I am looking at my scanner gauge taken from the ECU NTC temp sensor,

This is my point. All but Bobby355 say OP behavior is normal.

 

The WSM doesn't specify if the temperature is scanner temperature, gauge temperature or radiator temperature (with respect to the LH fan). I assume it's based on the radiator thermoswitch characteristics (which we have no reading of).

Perhaps Miro or someone can comment on the latency of this specific switch. If the fan cycles off after only 5 seconds, the OEM switch either doesn't have any latency or there is something else causing the rapid cycling. I can't see the coolant flowing through the radiator dropping 10 degrees in 5 seconds just by turning on the fan.

 

According to the Eurospares website, the 348 and 355 originally had radiator fan switch 140314, 85/76 C (185/170 F). While my 348 still had this switch, I noticed that it would take very long for the fans to go off due to rather low off point of the switch of 76C (engine temp about 80C). This was obviously unnecessary as the switch off at engine 80C was even below the thermostat opening temperature.

This radiator fan switch was, at some point, superseded by 158655, 88/82 C (190/180 F). When I bought the fan switch for spare, I noticed that what I received was an 88/82 C switch, higher and narrower switching range than the original 85/76 C. After some time, I installed it as I did not like the extremely long "on" to "off" period of the original switch.

The 88/82 C switch works much better as it does not unnecessarily bring the temperature way down like the orig. one. However, this switch will initially cycle on-off in short intervals with rather short "on" (ambient temp. abt. 32C). After some time (a number of short cycles), the "on" period will get longer and the cycling will be more like "normal". This is probably due to the heat soaking more into the engine (and transmission) which requires longer "on" time to bring it down.

Anyway, it appears that the 88/82 C switch operates with rather short on-off intervals. It does it initially even though the ambient is 32C and I can imagine that at 10C ambient it would do it not only initially but all the time. So, if you have an 88/82 C switch, short on-offs seem normal. It would be good to do another observation during the summer, on a hot day.

 

Perhaps I'm underestimating the cooling effect of the fan, but considering the mass/volume of water in the system (11 litres/11 Kg), I still can't imagine the temperature would change so quickly. I guess, as you say, a non-heatsoaked engine has less resistance to its temperature being changed.