355 Let's Talk Oil Temps and Cooling Fans

https://www.ferrarichat.com/forum/threads/355-oil-temp.337082/#post-140806014

 

Have you checked that it moves freely inside the thermostat housing? Mine was stuck for some unknown reason. The tolerances are quite tight.
Also, what's the condition of the water rad in front? Is there a blockage or collapsed fins etc? (apols if covered in the other thread)

 

Or maybe your oil temp gauge is kaputt

Lots of worst case scenarios. At least it's not oil pressure.

Is Jeff seeing abnormal coolant temperature values? You would think that if the radiator was blocked, there would be less cooling with only one radiator working.

Since you have abnormal fan control, why not replace the NTC sensor? The fan sounds like it comes on way too early. An overreading sensor would also affect engine management.






Image Unavailable, Please Login

 

That's quite enough of your well-considered logic and sensible approach.
I'd say the problem stems from not having spent a minimum of 12k on your last service...

Oil flows around the engine, the tank and the rad. The thermostat regulates flow into the rad. The only 'moving' parts are the stat and oil pump. Assuming pressures are normal (ie oil pump working OK), then it's either the stat not doing its job, a blockage or the oil rad isn't cooling (check the condition visually).
Stating the obvious, is the oil level OK? V low oil will affect temps.

Oil pressure senders can be suspect (near the filter) but don't know if temp senders are prone to failure.

As for that fan, as above it seems to be getting an odd signal so maybe look at swapping that sensor. Slight bugger to get at and may need to drain the coolant, but far from impossible.

Lastly, to answer questions,
1. My RH fan cycles, but if the car has been thrashed and is hot (ie gauges vertical or just over and idling), both fans run continuously (I think)
2. If its been driven normally and temps are vertical, the fans cycle
3. When the stat was stuck, oil temp would be middle if gauge under normal driving but even short spirited driving saw it up to first mark past vertical and pressing on would rise to near second marker. Now, it barely moves past vertical and also warms up quicker...

 

Check the accuracy of the gauge. I regularly see incorrect oil temp readings. When changing oil I use an IR thermometer and see lots of incorrect gauges.

BTW. Modern high quality synthetic oil is good to a little higher that 300 degrees but a 355 should not go that high. Also the fan is pretty superfluous at running speeds. It is really only a contributor at low speeds or stopped.

 

OK. I'd try pulling the stat out of the housing and see how easily it moves up and down. If it's wedged in position, that'd give you the symptoms you're seeing. Just a thought.

 

Not sure either. The connectors can get contaminated with oil during an oil change, but that's more likely to increase the circuit resistance, making the displayed temperature drop.

https://www.ferrarichat.com/forum/threads/oil-temperature-sender-thermistor.672339/#post-148972223

Is there a reason why your car is idling at 1250? Also, your oil pressure seems a little high. What was the temperature that day?

 

What are you aiming the thermometer at?

 

Meaningless. And the 2 very different readings are proof of that.

Point it into the oil tank at the oil itself.

 

The temp gauge is showing like 230-240, I wouldn't be worried about that. I've seen as high as 250 on track in mine, above that and I'd probably go to a 50W oil.

 

The last hash before red? Looks like 265.

 

The first red would be 292.5 (though I doubt the gauge is that precise).

 

Can you recall at what temperature the RH fan came on? Did it come in early like before?

 

Sorry, was that water temp or oil temp?

 

You cannot judge whether the fan is coming "on" early (or late) by looking at the oil temperature as there is no relation between the oil temperature and switching the RH fan "on" (or switching of the LH fan for that matter). Both fans are switched "on" or "off" only by reference to the coolant temperature (the LH fan also by the AC pressure). So, if your RH fan comes "on" at about 190F (88C), it is coming "on time".

The oil temperature triggers, and is controlled by, only the mechanical thermostat. The engine ECU, which switches the RH fan "on", does not "know" the oil temperature but only gets the signal of the coolant temperature from the coolant temperature sensor.