Good afternoon, I took the 355 for a ride today; I was driving on the highway around 3500 RPM & noticed that the oil pressure gauge was pegged to max. I got off the gas & let it idle in neutral & it went back to 70. The moment I touched the throttle; the gauge quickly went to 140. No codes were thrown related to oil pressure, etc. I turned the car off & tried again. Same thing. Idle around 70 & 140 when I hit the gas. Most likely the oil pressure sending unit? Thanks Image Unavailable, Please Login Sent from my iPhone using FerrariChat.com mobile app
Car is running perfectly. No smells. Nothing besides the gauge indicates an obvious issue. Thanks again. Sent from my iPhone using FerrariChat.com mobile app
High resistance in the oil pressure wiring means higher pressure indications. I would clean the oil pressure sender electrical contacts and check their tightness before changing the sender. The sender can be a bit of a pain to remove sometimes. An extra large spanner* and a lot of torque is required. Apply heat and penetrant as required. *24mm
I notice that the water is not even up to temperature (yet), so I suspect the oil is still way below 'nominal' temperature. When my car was newer (20K miles) it would cold idle near 70 PSI, so there is nothing <particularly> wrong with that data point. What I was told by the Ferrari dealer was that you should never "hit the throttle" until the oil had reached 180ºF. It is OK to drive around as that warms the engine faster than idle, just don't use more than ½ throttle. a) we don't know the temperature of the oil at startup, or the ambient temperature. b) we don't know the oil weight-grade in use. (a) if the oil was "pretty cold" then 140 PSI might be seen at 3,500 RPMs with a 15W50 oil (or heavier) It could be the sending unit, or someone could have added a shim in the oil pressure blow off valve to make the oil pressure look higher when the engine is hot, or thee could be a problem. We just don't have sufficient information.
The car was running for 40 minutes when I noticed the pressure gauge. It has 10w 40 oil. Should I be concerned about the temp gauge? Thanks Sent from my iPhone using FerrariChat.com mobile app
Yes, dirty contacts are the most common cause of high oil pressure indications. This happened to my 550 years ago where the sender is located beneath the engine and near the undertray vent louvers making it prone to getting wet and dirty. After you clean the contacts, protect the assembly with a a Maranello Skunkworks boot available from Ricambi America... Image Unavailable, Please Login I put one on my F355 Challenge too,,, Image Unavailable, Please Login
A good practice would be to remove the sender and install a oil pressure gauge setup and read the actual pressure to compare to what the dash gauge was reading. Chances are that the problem lies in the sender, but it's nice to know what the pressure really is.
