Need help ! When cold, at 2000 rpm I see 3 bar... goes up to 4 at 3000 rpm At 90 C water & 70 C oil, the pressure remains lower, gets to 3 bar at 5000 rpm Is that 'norman's ? If not, what's the right value ? And why is it low now ? Thanks in advance, regards Marco
Defiantly lower than mine. What kind and weight oil are you using, I use Mobil 1 synthetic 15-50. Also how many miles on your engine? The owners manual gives a min oil pressure. Sorry I can give more specific answers but I'm not at home now to look it up.
The later 400i series had an oil pressure gauge going up to 12 kg/cm^2 and 6 was considered to be the "proper" oil pressure at, say, 4,000 rpm. The owner's manual lists a minimum oil pressure of 4.5 kg/cm^2 (64 psi) and a maximum of 6.5 kg/cm^2 (92.5 psi). My 400i used to run half a needle under 6 most of the time although sometimes it would be right on the 6 while running at highway speed. At idle and warmed up, it was typically around what I would think was the 5 area. I used Mobil 1 15W-50 in my car summer and winter. IIRC, the earlier 365GT4 had an oil pressure gauge that went up to 10 kg/cm^2 and centered on 5. Usually gauges are set up so that "normal" operation is in the middle of the range. I don't know if the 365GT4 had a lower "normal" oil pressure than the 400/400i. Note that all of these oil pressures are higher than what we might be used to in other cars. For example, 6 kg/cm^2 translates to something like 85 psi.
Marco - that's definitely not correct, and not enough - if the gauge is reading correctly! At the temps you quote, the pressure should be around 5 bar at anything above idle speed - however, there are possible reasons for a low reading. Firstly, fit a mechanical gauge to check the operation of your electrical sender and dashboard, if it reads the same you need to further investigate. Secondly, have you changed oil brand ie has the pressure always been this low or is this a recent occurrence? Thirdly, the oil pressure relief valve is adjustable and easily accessible on the left hand lower part of the engine's front cover - it would be worthwhile seeing if screwing in the adjuster has any effect (and it is a possibility that the relief valve itself is at fault, with dirt on the seat). An oil and filter change might also be worth a try, but certainly some investigation is required as low oil pressure may mean big trouble if ignored! Fingers crossed, Howard.
Thank you all... you confirmed my concern (unfortunately !!!) and the need to take action. I'll follow the course of action indicated by Howard, will feedback Re the oil I'm using, it is an Esso mineral, not modern synt that weren't available in the 70's... it's abt 2 kmiles old Cheers, Marco
Forgot to say that my 365 is now officially 'Targa Oro' by Automotoclub Storico Italiano', that is the official Italian certification body, after analysis and verification. Three years of sweat and tears, but eventually mission accomplished
I'm pretty sold on AEHaas's research on motor oils/viscosities: http://www.ferrarichat.com/forum/technical-q/136052-motor-oil-all-chapters-inclusive-copy-save.html Bottom line: Low pressure=high flow, high pressure=low flow! Lower viscosities flow freer. I remember him recommending 0/30 from Renewable Lubricants years ago, using it in a # of his cars. Since I've lowered my viscosities, my engine is running cooler both oil & h2o, & pressure is down. Minimum pressure for engines=10psi/1000rpm!
The guy who built my racing engines always told me that the volume of oil and how freely it flowed through an engine was more important than the absolute oil pressure.
John, Racing engines are my weekday job, and I agree with your engine builder up to a point - but you also have to consider that when your engine was designed and tested, clearances and pump capacity would have been aligned with oil grades available. Obviously, as time goes by and we've learned more about oils and pumps etc, we can re-invent some of this stuff - but in a lot of cases it's not really necessary as the original spec works fine. Just my twopennyworth Marco, Congratulations, that was worth the effort - car looks terrific!! Jealous now. Howard.
Marco, Please check the oil pressure sender. I have replaced mine recently because of low pressure indication as well. My 365 was still fitted with the original sender, for some reason it failed. Cheers
kliko, haven't seen you here in a long time, hope all is going well with you, if you ever make it up to EIL let me know.
It is definitely the sender, which looks like the original one ! It ttok a while and a lot of patience to remove it, we tested with a mechanical and pressure is ok !!! this is really good news... on the other hand, I couldn't find (yet) a replacement, so I'm investigating on repairing this one... it seems as though ther is still soemone able to do the job will keep you posted
Marco, that is indeed good news - and well done for persevering! Every time I watch the oil pressure gauge go to the middle I think of you... Howard.
absolutely Howard, it's really a bad feeling... like Doomsday has come... and you think of all the thousands parts in the V12 that would remain without the fundamental help from oil... and what would happen to them... fortunately enough, I should come back to a more relaxed life quite soon; you can imagine my face when I've seen the test gauge going up, in the right zone !!! I'm in Oxford today, but just for a few hours... will tell you when I come next time, maybe we can meet again and share experience... how's going with your F ? hope everything is good Bye for now Marco
I could not find any new sender with the right pitch... I'm not an expert, fortunately enough the mechanic found a small company in Turin who could do the job... a bit expensive (at 200$), but I'm told organ be cheaper now that they know what to do If anybody is interested, I can ask
