Oil pressure guage reading...Need Help! | FerrariChat

Oil pressure guage reading...Need Help!

Discussion in '348/355' started by PA Charles Ferrari F355, Apr 3, 2010.

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  1. PA Charles Ferrari F355

    Apr 3, 2010
    74
    Chester County
    Full Name:
    Charles B.
    #1 PA Charles Ferrari F355, Apr 3, 2010
    Last edited: Apr 3, 2010
    I just purchased my first "entry level" Ferrari after 5 weeks of research from Drive Line Performance Cars out of Jacksonville, FL. Great honest father and son team who were excellent to deal with right from when they picked me up at the airport at 10pm. I settled for a 1997 F355 Spider with only 11,977 miles, all carbon fiber interior including door sills, tubi exhaust, 2 years left on the engine out service, great clean car. Steve from Omega Motorsports did my PPI. It was delivered by Intercity which I would highly recommend with a great driver named Steve who helped show me how to angle it in my tricky drive.

    My question is as I drove it my first day yesterday after it was delivered, I noticed that on my drive home after joy riding it for an hour was the oil pressure guage was riding at 3/4 of the way to the end. I calculated it to be at 105 psi. Is that normal? Also I drove it a short distance today and it seemed to be only at 35psi(2 bars) and when it idled it was at only one bar...17.5? Since my mechanic does not have weekend hours I wanted to know if I could drive it safely tomorrow for 2 hours on a trip an hour each way and feel secure I will not screw up my engine. I figured I would check engine oil levels tomorrow after letting it warm up as the manual states to do to make sure I have enough oil. Any guidance would be appreciative!
     
  2. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
    18,221
    Twin Cities
    Full Name:
    Tim Keseluk
    There are quite a few variables involved including oil type and grade, operating temperature and engine RPM that will influence indicated pressure.

    It is possible that your pressure gauge (and sending unit) is less than perfect, this is not uncommon.

    I suspect you are okay but a comparison to a mechanical gauge of known accuracy would be useful.
     
  3. AceMaster

    AceMaster Three Time F1 World Champ

    Feb 6, 2009
    34,777
    Ontario, Canada
    Full Name:
    Mike
    First off, congrats on your acqusition of the lovely 355.

    Although the pressure you are seeing is a lower than normal, what Tim mentioned makes sense.
     
  4. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    9,732
    On my 95 with 60K total miles and 5K track miles on the clock:

    My first oil pressure sending unit would send 105 PSI on new oil and 100 PSI on oil after a track day (high speed shearing has taken place.) On my second sending unit, this reads to 90 PSI on new oil and 85 PSI on scalded oil. This is to be considered normal oil pressure over 3K PRM (wihtin the accuracy of an uncalibrated sending unit).

    On 10W-40 oil, I idle at 40 PSI, 30 PSI if I'm comming off the track scalding hot.
    On 10W-30 oil, I idle at 35 PSI, 20 PSI if I'm comming off the track scalding hot.

    The old rul of thumb is that you need 10 PSI for every 1000 RPMs for adequate FLOW (not pressure: flow).

    So the trick is how quickly you get up to the pop off pressure. In my car afte full warmup (oil temps = 200dF) my oil pressure guage reaches 85 PSI by 2800 RPMs. When the engine was way newer, It reached this pressure by 2000 RPMs. I suspect rather stongly, that if it reaches the pop off pressure by 4K PRMs, there is little to worry about.
     
  5. intercity

    intercity Karting

    May 5, 2009
    106
    PA Charles Ferrari F355,

    Thank you for the kind words, we really appreciate your business. Glad to hear your F355 Spider arrived safe and sound with Steve. If there is anything we can do for you in the future please feel free to contact us.

    Thanks,
    Jim
    Intercity Lines
    www.intercitylines.com
     
  6. tashier

    tashier Formula Junior

    Sep 8, 2008
    573
    Oregon
    Full Name:
    Sean
    I had erratic readings on mine. Pulled the Instrument Panel and tightened wires on oil pressure guage. Problem went away.
     
  7. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,045
    USA
    #7 f355spider, Apr 5, 2010
    Last edited: Apr 5, 2010
    +1, the figures are within what might be consider "normal" as the gauge is not super accurate. More information would help...such as what weight oil is in the car, and is the car fully warmed up when you get these numbers? As mentioned above the mechanical gauge test would confirm your readings.

    Do read the owners manual thoroughly, and take note to not exceed 4k rpm until the oil temp reachs 170 degree F or there about (in the manual ;) )
     
  8. pyroguy

    pyroguy Formula Junior
    Owner

    Dec 20, 2006
    669
    Minnesota
    Full Name:
    Steve
    +1 on what Tim (2NA) said. I have a 1996 355. Usually sits around 70-80 (plus/minus) but will creep up to 105. Usually at idle, warmed up runs around 35-40. Woulds be nice to compare to a mechanical gauge but unless i run some plumbing into the cockpit that will be unlikely!

    Steve
     
  9. PA Charles Ferrari F355

    Apr 3, 2010
    74
    Chester County
    Full Name:
    Charles B.
    #9 PA Charles Ferrari F355, Apr 16, 2010
    Last edited: Apr 16, 2010
    I appreciated all of my oil pressure advice. As the adage goes we all learn something new every day to help others in Ferrariville. Had the car in last week to my non Ferrai dealer shop at CB Foreign Cars in the Kutztown, Pennsylvania area, well worth my 1 hour 15 minute ride each way. My Ferrari mechanic/proprietor for life John who is very knowledgeable, looked the car over and will be replacing my pressure sending unit which is giving out inaccurate readings on ocassion.

    Also, John at CB Foreign Cars taught me a inexpensive fix/trick for the convertible top that if it was taken to the Ferrari dealer, would have resulted into a major exuse to charge me a high repair bill.

    When opening my top for the first time in PA just as the manual stated, it was having difficulty opening the entire way. After a few times trying and fearful of the beep sounds I thought I was in for a major repair. John stated over the phone not to sweat it as he would share his simple trick to fix it when I bring the car in for him to check my oil pressure concerns.

    THE TRICK: You need to follow the same opening steps as the manual. I play it safe in that I move the seats forward and open the windows before hitting the top button. When you get to the part where you unlatch and open the top until you hear the beep and BEFORE you hit the convertible top button..............you push the underneath portion of the top "slightly" up with your fingers. This allows the bow to fold in better before the folding actually starts, thus preventing it from having problems closing, not to mention the stress you have by hearing the beeping noises of failure. Information like this surely can't be found in a Ferrari manual or from a Ferrari dealer without a costly repair invoice. Hope this inexpensive lesson learned can help other like it did me.

    Anyone looking for a knowledgeable, honest Ferrari mechanic in the Pennsylvania area surely should consider CB Foreign Cars at 610-683-5777.
     
  10. stevew3765

    stevew3765 Formula Junior

    Oct 27, 2012
    716
    Tulsa, Oklahoma USA
    Full Name:
    Steve Wool
    Yes. My 97 f355 spider is having issues such as this. It had a major done at 30k in 2004 and it currently has 39k on it. So, I am having a major done in a month or so. My oil pressure reads 20 to 30 at 3000 rpms so my mechanic told me to stay out of the car until we do the major and we would take care of all that stuff. Interesting that this issue seems to be a characteristic.
     

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