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Discussion in 'Technical Q&A' started by marinelo, Aug 10, 2005.
What does your oil pressure read at idle at normal temperatures and also at rpm?
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At idle mine is around 40----While driving it is around 70.
Mine reads fairly low at idle maybe 20. At 75 mph it reads around 80-85. I've been concerned about the low pressure at idle myself. Hope this helps
Just remember what you're seeing is not an accurate reading, what you have is an electronic sender unit sending a signal to an electronic guage - any worries with oil pressure then you should start checking readings with a master / manual guage.
Max pressure should be no more than 92-95 psi. If it reads higher, then get it adjusted, there was a TSB on this from Ferrari. Check the archives, many threads on this problem.
I have had this same issue especially when it is 90+ out and the oil temp is at max. I have disscussed with my mechanic. According to him if you have good oil pressure at start up when the oil is still cold then you are in good shape as the oil sending system on 308 / 328's is notoriously inaccurate especially as the age of the sending unit and guage increases.
He said it would be about $150 to $200 to replace the unit / guage so maybe next time I am in for service I will have it done.
The pressure on mine reads about 85 at start up. After it warms up it's still at 85 while on the gas. Drops to around 40 or so, sometimes a bit less at idle. I just replaced my sending unit also. I was getting some crazy readings before that. I was considering putting a small manual guage between the sending unit and the housing but didn't get to it. Something I'm still considering in the future.
There is nothing like a Ferrari, there never has been and never will be!
My 78 308GTS suddenly started having high oil temp readings...all other gauges read normally. A new Veglia oil temp sender fixed it. $14 for the part, and about 10-15 minutes to change out (have to jack up the car).
Running Mobil 1 0w-40 and outside temps around 90 - 95, I get just under 3 bars (around 40 psi) at idle and it increases to 6 bars (90 psi) by 2,700 rpm.
Mobil 1 is synthetic-correct? I was told not to use synthetic! Yes or no?
Yes, full synthetic. I have had no problems with leaks running synthetic oil. The prior owner used synthetic as well during the time he had it.
I've heard of leaks happening after a car has been run on regular oil and then switched to synthetic. See this thread, the majority running sythetic oil in their cars have seen no adverse effects, but a some did notice more leaks after switching.
Synthetics are best. I am using 0-40 Mobil 1. My guage is inconsistent , but it always shows good pressure at idle. Dave Helms says as long as it moves, don't worry.
$14. for a oil pressure sending unit!!??? The best deal I could find was $136. Crazy. Was it made of plastic? Mine was so tight that I had to take off the whole casting, took it to the shop where I was getting the new sender, the shop owner then put it in a vise and removed it for me. Thank you A.T.D in Portland OR. (shamless plug) I hadn't mounted a vise to my bench yet so didn't do myself. Allthough there is one there now! Used it to tighten the new one in the casting before the install. Only 3 nuts to remove the casting so it wasn't too awfully difficult. Took about an hour though. Not like I was trying to set any records. It was fun. I use Castrol 20/50 in the Dino. It's what the previous owner used and what RTGT recommended. I don't care for the synthetic oils myself. I know they are supposively better and all, but are prone to find any little place to leak they can. We change our oil so often that the longevity you get with the synthetic is really a moog point. But what the hey. Everyone has thier favorite brand. Hope you get the problem sorted out. Seems your not alone. Which is allways good to know.
There is nothing like a Ferrari, there never has been and never will be!
Turns out I am getting some dripping from the studs on the oil pan [happens when the gasket gets pinched during pan installation]. In any event I told my mechanic to replace the sending unit when he does the gasket since the unit needs to be removed to get the pan off. Should happen next week so I will post before and after numbers.
oil TEMP sensor, not pressure. Synthetics have many more important advantages than longer service life....but that is for another thread.
Give a look here..
Be aware that early 328 have two seperate oil pressure bulletins, and a further one for cooler hoses.
There is a different length spring for the relief valve, and also an improved shuttle for the relief valve that reduces the oil surge on start up.. that can cause oil lines and/or coolers to fail.
I'm sure somebody has a scan/link to them. I only have paper copies.
Here is the link.
I've had the spring replaced a couple years ago and my pressures are generally lower. However, lately I've noticed my idle pressures to be 20-25. This seems too low. I'm not worried about it too much because the gauge is moving and goes up to 60-70 under use. Just something to inspect I guess next stay at Norwoods.
The Owners Manual (US) page 58 says:
The normal oil pressure is between 71 and 85 p.s.i. with engine at 6000 r.p.m.and oil temperature at 212 F.
When engine warm and at idle condition, an oil pressure lower than 64 p.s.i. is to be considered normal.
In the Specifications page 20 is says:
Oil pressure (warm engine) between 4.5kp/cm2 and 6.5kp/cm2 (approx. 60 and 91 psi).
I interpret these figures as limits, whereas the page 58 numbers are the normal pressures.
Mine is at 6kg (84 psi) at cruise and never below 1.5 (20 psi) at warm idle.
That's good enough for me.
Anybody ever seen the warning lamp go on???
'88 3.2 here - 80psi at 3,500 rpm warm, 40psi at idle while warm.
Three brief points:
1. Synthetics tend to be marginally less affected by temperature than non-synthetics, so, if you're experiencing low pressures at warm idle it's likely worth trying a synthetic.
2. That said, synthetics do tend to leak more if the car was previously run on non-synthetic oil. They don't actually cause leaks, rather, where seals were marginal before the synthetic will tend to sneak out past the seal where a non-synthetic may not due to different viscosity and chemical properties. Said another way, the cause of the leak is a weak or marginal seal - the synthetic oil just tend to make this condition more apparent.
3. If you're getting crazy readings then definitely check the sender. Also, check that the ground strap from the engine to the chassis is free of corrosion. I had crazy readings and traced it down to a corroded ground strap.
On first start-up it goes right to just to the left of the 85 mark. Stays there while running, only once have I seen move right on top of the "85" and I was doing 120 mph for about 30 minutes at the time. On warm idle it drops to around 40. When having the car serviced at Tim Stanfords, he said that was normal.
My oil pressure reads about the same as most of you. I did ask my mechanic about the "low readings", 60-80 during normal or heavy driving. He said those gauges can't always be trusted. He said, "you are fine unless the red light comes on, the red light doesn't lie". I have never seen my red light so I guess I'm o.k.