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Acceptable 328 oil pressure levels?

Discussion in 'Technical Q&A' started by rob lay, Feb 20, 2004.

  1. rob lay

    rob lay Administrator
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    Dec 1, 2000
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    I think everything is fine, just trying to learn a little more about my car.

    Low cruising RPM's the oil pressure is about 90 lbs, or just a little past the center 85 mark.

    Getting on the RPM's it goes up to the 3/4ths mark (looks to be about 135 lbs) at 5k. Pressure doesn't increase too much past 135 lbs 5k to redline, maybe just 5-10 lbs.

    I use Mobil One 15w-50.

    Thanks,
    rob
     
  2. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
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    The rule of thump is 10 PSI for every 1000 RPMs.

    And while my F355 has 80-90 PSI oil pressures at 3,000 RPM cruising, it tops out at 105 PSI. These pressures are the same with 20W50 and 10W40 oils.

    I would think 135 is a little high, but I suggest you verify your numbers, and then have the oil pressure sending unit checked for accuracy before looking at how to reduce the oil pressure.
     
  3. flyingboa

    flyingboa Formula 3

    Nov 27, 2003
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    As posted in a recent thread. my 328 behaves in a very similat way to yours. Manual calls for lower pressures anyway, as you well know.

    Ciao

    Eugenio
     
  4. flyingboa

    flyingboa Formula 3

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  5. f355spider

    f355spider F1 World Champ
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    Rob,
    My 87 328 GTS was recording the same pressures as yours. Changing oil weights had little effect. I consulted with my Ferrari tech, and he did some tests, to include attaching a mechanical gauge. He confirmed that my dash gauge was pretty close (reading just very slightly high). The WSM says oil pressure should not exceed 92 psi (or there about) at 6k rpm. My guy changed a spring that regulates the oil pressure. Now it does not exceed an indicated 95 psi.


    BTW, there is a TSB on this issue on 328, and my car was supposed to have the updated part, but still read high.
    http://bingo.cdyn.com/ferrari/328_bulletins.pdf

    See page 104. BTW, there is also a bulletin on the engine damper bolt...that it is now supposed to be installed with loctite. :) See page 98.
     
  6. rob lay

    rob lay Administrator
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    LOL, but only if the bolt is actually torqued down right. Otherwise a $1,600+ problem. :)
     
  7. f355spider

    f355spider F1 World Champ
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    Rob,
    As a preventive measure, I am having my mechanic remove the damper bolt, apply Loctite 242 per the service bulletin, and retorque to 145 ft/lbs....

    He said it is an easy job, and will only take a few minutes, though he has never recalled one coming loose. I noticed my car was produced before they started using Loctite on the bolt.
     
  8. Rick328GTS

    Rick328GTS Rookie

    Jan 26, 2004
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    Dave,

    What year or serial # did they start with the loctite? Just would like to see where my 328 falls in .
     
  9. rob lay

    rob lay Administrator
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    Just heard back from Norwoods, Ken put a mechanical guage on and my dash guage is accurate. The car is running 140 lbs. warm above 5k. That's a problem, I'll let you know when they find the root cause. I think they're going to look at the spring first.
     
  10. AEHaas

    AEHaas Formula 3

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    It is amazing to me how even Ferrari mechanics think that if your oil pressure is too high (most do not think that there is such a thing as too high) the cure is to decrease the oil pump output.

    The manual states the target pressure (usually around 10 PSI per 1,000 RPM) to aid the owner to select the proper oil wt. to use under the conditions that you drive and the condition of your engine.

    Oil is really the easiest thing to pick. Use the oil that gives you the appropriate pressure for your application.

    The worst thing you can do is minimize oil flow. Lubrication in engines is oil flow. More flow equals more lubrication. Thinner oils give better flow, more HP, better gas milage, less friction and lower engine temperatures. The lower temperatures alone decrease engine wear, and wear on rubber and plastic parts among other things.

    aehaas
     
  11. f355spider

    f355spider F1 World Champ
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    aehaas,
    No arguement, but the 328 had a known issue with the oil pump pressure, and they did change the spring value during the middle of production. My guess is that during use, the spring must have changed in value and that is why the went to a different spring later in production.


    AIRWOLF328, there is no VIN number stated, only production date. Those made from 8/87 on have the updated spring.
     
  12. rob lay

    rob lay Administrator
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    Ken just opened mine up and found the old spring. The new one is a whopping $4!
     
  13. f355spider

    f355spider F1 World Champ
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    Okay check this link:http://bingo.cdyn.com/ferrari/328_bulletins.pdf

    If you look at an early 328 recall (page 59), you'll see that when they recalled the oil cooler lines, they also went ahead and updated the "oil pressure regulating valve assembly" to the current production version. This new valve has "3 lateral holes to regulate oil pressure".

    Later, they made another production change (page 104) that did not include a recall to update earlier cars. This spring is "more flexible and slightly shorter".

    Not sure what all this means, but appears they are trying to lower the oil pressure some.

    My car was built after the first recall, but before the production change on the spring. My car was reading very high oil pressures, confirmed with a mechanical gauge. I don't know where my mechanic sourced the spring, but he found one that brought the pressure within the factory specification. (btw, I am currently using Shell Rotella T synthetic 5w-40 motor oil.)
     
  14. 4re gt4

    4re gt4 Formula 3

    Apr 23, 2002
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    They ARE NOT restricting oil flow with a new/different pump spring. The spring simply controls a pressure regulator. Full flow, it just caps the max pressure.
     
  15. AEHaas

    AEHaas Formula 3

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    If you decided to use 90 wt. motor oil you would probably hit 90 PSI at 1,000 RPM. If you set it to pop off at 90 it still does not make it right. You will not get excessive pressures but you will get little oil flow.

    If you rub oil between your fingers common sense tells you that thicker oil is better. If this is true then put 90 wt oil in there.

    I am trying to help people here. Only one person so far is listening. It is amazing to me that after all the data I have posted over the past year to educate the public only one person is absorbing anything. I have quoted multiple oil manufacturer chemists including race oil manufacturers as Redline, 2 - FNA head technical experts, Ferrari owners manuals, SAE and ASTM as well as API documents. I have given examples ad nauseam.

    Nobody has given any solid evidence that thicker is better, only "so far no problems" whatever that means.

    aehaas
     
  16. rob lay

    rob lay Administrator
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    aehaas, I'm on board with you, but maybe you were counting me already. :)
     
  17. AEHaas

    AEHaas Formula 3

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    Rob,

    Put your pump back the way it was. Change the oil to 0W-30 Mobil 1 and give us the pressures at various RPM (at operating temperature). If it does not work right I will pay you $50 for the oil.

    When you change the oil make sure you disconnect the oil pipes to get a real, full oil change. Also, make sure you are putting in the newest SL rated Mobil 1. There is still some of the older, SJ rated stuff on some shelves.

    ali

    Edit - Do not be afraid of the darker color. The two oils I am using, Pennzoil dino and Mobil 1 both went from an almost clearish color when SJ rated to a darker color when SL rated. Documents state the color is from new additive packages. The Shell Helix is the most clear motor oil I have ever seen. The last time I checked it was still only SJ rated. SL is a significant improvement when I look at the numbers. I liked Helix before but would not use it until they spec it to SL.
     
  18. 4re gt4

    4re gt4 Formula 3

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    Huh?? Nobody said anything about using ultra thick oil. With any *reasonable* weight oil, the pressure regulator in the oil pump will limit the max pressure. 0W30 or 15W50. It won't matter as far as the regulator is concerned. The thinner oil might take a few more revs to hit the max.

    Changing the regulator spring has NO influence on oil volume.
     
  19. Dave

    Dave F1 Rookie

    Apr 15, 2001
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    An old timer once told me...
    Son, when it comes to oil pumps,
    you want high volume, not high pressure.

    The things in life we remember.
     
  20. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
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    I was wondering if it was you or I
    or
    whether the sum of both of us only counts as 1.
     
  21. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
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    In my case, the thinner oil did not reduce the max pressure*, the typical idle pressure, or the RPMs required to achive max pressure. In fact, when leaving the track after an extended run, the idle oil pressure was HIGHER with the thinner oil because it ended up at LOWER temperature than the thicker oil.

    *Within the accuracy of the guage
     
  22. 4re gt4

    4re gt4 Formula 3

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    What seems to be overlooked here is that the original post stated that Rob was getting pressure that was WAY too high. Regardless of what oil you are using (within reasonable bounds), the regulator *should* limit pressure to some preset value.

    My mechanic has seen the regulators in 3X8 series cars stick. They don't function. Pressure then rises nearly linearly with rpm and doesn't level off. Also, apparently some cars have an improper spring that causes too high maximum pressure.

    Thinner oil may help Rob's issue, and I won't argue that it may be the preferred choice. But point in fact, the pressure regulator isn't working correctly.

    These engines (at least when healthy) have pumps that put out lots of volume and potentially lots of pressure. I'd be VERY surprised if you don't still see an overpressure situation with thin oil. My car would hit the regulator (90psi) at about 2000rpm with 5W30 Mobil 1 with temps in the normal range. With cold oil, it was there at idle.
     
  23. AEHaas

    AEHaas Formula 3

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    At start up my 575 oil pressure max's out at around 135 PSI yet when up to temperature it max's at 100-110 PSI. I keep meaning to call Adam Rowley at FNA and ask him but I keep forgetting.

    My theory is that the blow off pressure is temperature dependent. This makes sense. When the oil is cooler it takes a higher pressure to get flow whereas at operating temperature less pressure is needed. It cuts off sooner to minimize engine drag. More flow may just not be needed.

    aehaas
     
  24. 4re gt4

    4re gt4 Formula 3

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    Hmmm.... The pump/regulator system in the V12s may be different. My V8 reaches a max of about 90lbs hot or cold. Maybe 5lbs variance max. When hot, you can rev the engine and the pressure needle rises rapidly and slams to a halt at the 90lbs mark.

    I had some oil press sender probs a while back, so I put on a mechanical gauge to check. Same behaviour.
     
  25. f355spider

    f355spider F1 World Champ
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    AEHAAS,
    I hope you don't think I am arguing with you, only stating that Ferrari knew they had some oil pressure issues with the 3.2 328 motor, and both a recall and production change were made to address it. Even so, it appears to persist on some motors. My car read close to 100 psi (warm) at idle with Mobil 1 15w-50, and switching to Shell Rotella T (synthetic) 5w-40 had no effect. Perhaps Mobil 1 0w-30 or something else may have helped a bit, but based on the Shell experience, I wasn't betting on it, and went ahead and had the pressure regulator adjusted.

    I guess I am not fully understanding of how this pressure regulator works. I was under the impression that it only controlled pressure, not flow, as Hans was saying. Is this not correct?
     

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