All, I have noticed that the oil pressure is taking longer and longer to register when starting the car. I do believe the gauge too as you can hear a slight difference in engine note when the oil starts to flow. Not talking 10 mins but perhaps 3 seconds once the engine fires. It seems to be getting worse too but this could be due to hotter weather/thinner oil? During normal operation, the oil gauge reads exactly what the manual specifies at 6000rpm and at idle, so this is good and suggests the oil pump is healthy. I am using Shell Helix 5w40 changed about 1500 miles ago and I keep it topped up to max. Is the oil draining back through the pump when the car is not being used? Does the oil system contain a non return valve to keep it primed and this is stuck. Cold oil viscosity too thin? '82 Euro QV Any comments? Thank you!
The gauge is in simple terms....trash. Don't spend too much time worrying about any information derived from it. If in fact it does take 3 seconds (I bet it doesn't) you really have nothing to worry about. If you want a base line install a temporary mechanical gauge for a couple of days driving and see what it really does. The fact that Ferrari for most of the companies history has used instruments that even Trabants would have been ashamed of using is to me a bigger black mark on the company than the sticky black crap on the plastic parts. Harbor Freight sells better instruments.
Odd that he is noticing a difference... But may be it's slightly imagined now attention is focused in that area? Mmm tough one. I'm always inclined to think that peoples instincts are usually correct when someone notices something like this. Sorry not much help, but I would make try for some comparative data. Regards Bell.
With warm weather I would expect it would build up pressure more soon. When colder the oil is more thick and being cold it takes a bit to get into all the oil passages in the engine. Usually the check valve is in the oil filter. Could be a wacky oil filter where the check valve is not working and if it is a Fram... they are already wacky when they come out of the box. I ruined a cam with such filter in my Alfa QV. I have no other words for it then that they are junk. Now I don't know actually if the check valve is in the oil filter or in the engine... it is either way. I would try another oil filter as it unlikely that it is the oil and you changed both I assume
Yes both oil and filter were both replaced. The filter is K&N. I hadn't noticed the increase in priming time after the filter was changed, I have probably done 1500 miles since and thought I would have noticed before. I am an mech engineer and understand the importance of this sort of stuff, so my eyes are glued to the gauges! Bit of a strange one. I might investigate the NRV a bit further. Perhaps replace the filter if it has one but leave the oil in. Thanks
I have found out that the filter currently on the car does have an integral check valve. Since this is all i can think of at the moment, and that it is cheap, i am going to swap it. Ill let you know.
Please consider using a UFI or Baldwin oil filter. Other filters have caused engine issues on their own. Fram filters are not made for the very high cold oil pressures and can burst. Not sure I would risk a $20k engine on a K@N oil filter. You are smart enough to be concerned about the build up time of the pressure, please consider a proper filter.
Mine is exactly the same, and yes as you say you can feel the difference as the gauge registers. What you really want is a longer cranking time to allow pressure to accumulate but they start so well from cold. You won't cure it so keep away from the throttle and enjoy. Nick
These valves inside the oil filter are more often called an "anti-drainback valve" (but they are so simplistic in construction that calling them a "valve" is almost too generous -- and they are known to fail). Almost all oil filters have them, but for your inverted mounting situation you want an anti-drainback valve AND an internal standpipe to give minimum average time to pressurization -- get the Baldwin or UFI (or, IIRC, there's either a Hastings brand or a Mann brand oil filter in your part of the world that also has both -- if you do a search using "anti-drainback valve standpipe" you should get many prior threads)...
All, I can confirm that the problem was caused by a faulty filter drain back valve. The filter has now been replaced by a Mann unit. It now takes around 1s only to register pressure. I have returned the original filter to the manufacturer, i was going to get a can opener to it but wanted the money back! See what they say Ant
Good to see Antwan! Got a Mann as well. Good filters! Next I will try a UFI for a change. That'll be soon as I am close to have driven 10,000km for an oil change.
None of my cars has ever needed much oil pressure to begin with. Let me start with my 1965 Corvair Monza convertible. I put Mobil One in it back in the early 1980's and at idle the oil light would come on. I think that was 5psi. So I added some STP and after that used 40 weight and the light never came on. But here is the thing. I knew that engine was worn out when I bought it due to all the blow by. However, it ran ok so kept driving it figuring on an overhaul someday. That was thirty years ago and probably 45,000 miles. I would change the oil every year or two, and it needed a quart at about 500 miles. And I drove the bejeezus out of that car. Last year finally got round to an overhaul. Every last one of the rod bearings were exactly the same, and every last one of them was at the high end of new. Did not need even need an oversized bearing. Two of the pistons had previously been replace backwards and had broken rings which accounted for the blow-by and oil use. Also back in the those days I bought a 1984 Camaro Z-28 and man did I ever drive the bejeezus out of that car. Probably hit 7,000 rpm on my fastest 1/4 mile run after dumping the clutch at 4,000 rpms. Many many times. My experiment was to use synthetic oil and only change it every 15,000 miles. That was less then Amsoil claimed which was 24,000 miles. Anyway, after 120,000 miles it had no blow by and used no oil. Pretty much the same with my 1991 Supercharged Lincoln Mark VII. Ran it dead stock with 8psi and did not ever spare the throttle. It would cruise 130 mph at 3,000 rpm. After 190,000 miles it had no blow by, did not use oil, and ran like a scalded dog. Did not even leak oil. So I do not much concern myself with oil matters. PS: I could not run 8 psi with the standard torgue converter and 3.20 axle ratio. Just too wicked. So I installed a low stall speed truck torque converter and 2.73 gears. [Two seventy three]. Even so I could smoke the tires at the drag strip with a bit too much torque braking. God I miss that car. Wish I had never gotten rid of it. Swapped it out for that Corvair overhaul. AND it got 26 mpg at 60mph and never got less then 21 at any speed. Until I replaced the stock O2 sensors with modern Bosch units. Big mistake but the old ones were gone and replacements from Ford were like $500 so I paid for the gas.
