[markqv]

I had a nasty fright yesterday. Whilst waiting in traffic the oil pressure warning light illuminated. The oil pressure guage was showing just below the "42.5" PSI indicator. Increasing the engine revs only slightly brings the pressure up immediately and at normal engine revs the oil pressure if fine.

The car has only 30K miles on it and at a servcie only some 1500 miles ago by a renowned Ferrari specialist, the oil was replaced with fully synthetic. When the engine has been allowed th cool, the oil pressure is fine once more. Logic would suggest the oil is thinning at temperature.

Do I change the oil to a 20/50 or panic...

 

[Pete04222]

I wouldn't panic. 42 psi is fine at idle. There are differing thoughts on oil for the Ferrari. Some swear by the synthetics, others swear by the petroleum-based oils. I am of the latter. The petroleum-based oil will cause the rubber in the seals to swell, if you change to a synthetic, the seals will shrink and leaks will develop. I change my oil religously and I use 20W/50 oil made by Valvoline. I also add a quart of Lucas Oil Stabilizer at each oil change.

Since you did not have this problem before switching to the synthetic, I'd go ahead and change the oil to just straight 20/50.

 

[senna21]

As much as I like Pete I'm one of the Synthetic guys. I've never seen any proof of the "reverse swelling" effect that is claimed. A synthetic will protect your engine better than anything else. I run 15w-50 Mobil 1 in my turbo. I wouldn't run anything else. Trust your mechanic.

What weight are you running? Is it one of the new Zero weights?

 

[enjoythemusic]

Hi,

What il was used? Have Amsoil 20-50 2000 Racing Snyth in the 308 and works fine. As for the 4.? oil pressure, that is actually fine as i recall. Should max out at around 6 to 6.5 when the oil is hot and you are running 5,000rpm on upward... at least that is how the 1985 QV 308 "works" here and i would presume a Mondial is about the same.

 

[Stradale]

All modern high performance and high value cars from the factories use Synthetics. Ferrari, Porsche, BMW, Mercedes all use syntetics. Ask yourself, is there a reason why thaese manufaturers use them? Then decide what's good for your car.

 

[4kids3fish]

Stradale, as you say the current cars mostly use synthetic lubes. What I'm not sure about is whether the designers of modern engines, etc have had to take that into consideration when designing the seals & gaskets of the engines. In other words, are oil seals from the 70's made from different materials that are not as compatible with synth oil? I'm not a mech engineer so I'm unsure whether certain properties of the oil are "required" by older components, & are these properties missing from the newer oils? I'd be very interested in any responses on this.

 

[enjoythemusic]

Oil seals and other bits are fine with synth. The real situation is that you are using DECADES OLD seals so during the next major service have as many seals/gaskets replaced/updated as your wallet allows. The 1985 Euro spec 308GTS QV here does not drip ANY oil, does not have ANY coolant leaks, etc.

Of course it never hurts to have deep pockets and a GREAT mechanic

 

[markqv]

Thanks for all the advice!

I'm pretty comfortable about the oil pressure now - as for the oil pressure warning light, before I drop the oil I'm going to fit a replacement oil pressure warning light sender and see if that changes anything. An oil pressure check by a pro will follow also.

With respect to the urban myths about synthetic oil and seals etc, I can't say I was ever too concerned about that - but I was concerend about the tolerances of such an old engine being suitable for the viscosities of synthetic oils.

My daily drive is a Honda S2000 and the specified oil for that is a semi-synthetic. With a 9K redline, presumably Honda have thought through the lubrication issue pretty thoroughly - and it's interesting fully synthetic isn't the oil used.

I'll post my findings once I've fitted the new sender!

 

[4kids3fish]

Discussed this issue with the head mech at Sydney's Ferrari dealership yesterday. His opinion is that for 80's cars with a decent mileage either a mineral or "blended" oil is best. Not because of any seal compound issue but just because the synthetic viscosity is so much lower it will find more places to leak from!

He is putting a blended formula into the Mondial 3.2 (not blended by him - it comes that way!). I will try to find what brand, etc it is. BTW he also recommended a particular Agip oil as best for the older gearboxes to help with selection notchiness, & said the boxes were designed for that oil. I will get that info as well.

 

[markqv]

Great news! - the new low oil pressure sender has now been fitted. The light stays out even when the engine is hot and idling.

Oil pressure on the gauge is c. 85 psi when cold and 40-ish psi when hot - although it does fluctuate. Now that my nerves have calmed, I feel sure the problem is down to this car having such little use over the last 10 years - the low oil pressure warning light sensor may simply have just become sticky. I'm probably going to replace the oil pressure gauge sender too and may well have the engine oil pressure tested "properly" for good measure.

Thanks to everyone for the advice.

And with the temperature nudging 28 degrees here in England today, a good fast run hasn't thrown up any further issues.