Oil Pressure doesn't hold

[KalamazooJohnny]

Just installed the instrument cluster and started the car. The oil pressure goes up if I rev the engine, but goes right back down. Doesn't seem to be holding. What does this mean? What should I do?

[Fiatmonkey]

That was why Fiat took out the oil pressure gauge. Americans didn't like how low the oil pressure got. If you have any pressure at all you're probably fine.

Start the car let it run for 15 seconds turn it off, and the take off the oil cap. If the cam tower has oil in it then you are fine. Fiat Spiders are just weird cars.

[bulldog4444]

Hey Johnny,
It all depends. What do you mean by "up" and "down"? My experience (depending on the weight of the oil, 20w50 runs higher pressure then 10w40, etc.) is 15 to 30 psi at idle and 50 to 70 psi at 3500 rpm's and higher. A cold engine will show a little higher pressure because the oil hasn't fully warmed up and thinned out.

Everything could be fine but if you are experiencing excessive clacking noises, maybe you would want to do an oil change and install a new filter. Sometimes the filters get plugged and the pressure relief valve in them are bad. The fact that the pressure increases with RPM indicates your pump is working. Keep us posted.

Bulldog

[KalamazooJohnny]

Ok, this is sitting in the garage in neutral, as I have no seats or doors installed so I can't drive it.
I start it, and rev it up and the needle on the oil pressure guage jumps, at idle or around 1000 rpm according to the tac, oil pressure reads 0. At 2000 rpm, oil pressure reads around 10, up around 3500 oil pressure shows about 30. Let off the accelerator, it drops back to idle around 1000 and oil pressure reads 0. Oil pressure needle seems to be sticky between 0-10, like it doesn't want to let go of 0. I am using 5w-30 valvoline. Its what I use in all my cars. I recently changed the oil, like a month ago and start the car once or twice a week, but have only ever driven it a few hundred yards a few times in the last 2 years. I removed the oil cap and I can see oil on stuff inside there, and dipstick shows clean and at the full mark.
Any comments from anyone? Thank you.

[majicwrench]

Zero is not enough, esp cold. Get yourself a mechanical gauge and check the oil pressure with that.

Most of us use a thicker oil than 5w-30.

[124JOE]

trust that it IS GETTING oil
it may be lose conections
bad gauge or pinched line
mabey?

[bulldog4444]

+1 on the oil being a tad light. In California I used (and I believe recommended by my mechanic) 20W50 weight Castrol in the summer and 10W40 in the winter. Since I moved to Ohio and only drive my spider in the summer, 10W40 has been my go to weight. I would try a heavier oil first, a new filter just in case yours is bad and see/hear if there is any clacking coming from your engine.

[azruss]

the pressure gage sending unit has an extremely small hole that can clog with time. find an appropriately sized drill bit and clean it out. will help with gage consistency as well.

[Sunracer]

It should move up and down with engine speed, not hold unless you are cruising at a steady speed. When the sender goes it will work a bit when cold then hardly at all once the car is warm. If this is the case once you're driving it then time for a new sender. If the low oil pressure indicator light doesn't come on when it's running at normal idle speed when hot you are ok. Your oil choice is too thin for an old style motor that is probably somewhat worn. 20-50 is a better choice unless you are driving in very cold conditions.

[KalamazooJohnny]

I'm curious as to what other Michigan Spider drivers use for oil weight. I think there are like 4 or 5 Spiders in Michigan still right?

[Adam]

Can' seem to find a 20w50 with a high zinc content in my neck of the woods? As a result, I've run rotella 15w49 for the past few years without issue. I drive the car from april through the end of november as long as the fun is shining.

[Sunracer]

Can' seem to find a 20w50 with a high zinc content in my neck of the woods? As a result, I've run rotella 15w49 for the past few years without issue. I drive the car from april through the end of november as long as the fun is shining.

Comp Cams, Lucas and STP all make zinc additives, I add half a bottle at each oil change. PB : )

[bulldog4444]

I run Mobile 1 High mileage 10W40 and add the Lucas ZDDP zink. Add about 4 oz. to the Mobile which already has 1,000 ppm to give a safe 1,600 ppm. I just passed 330,000 miles so good oil does make a difference.

[ORFORD2004]

Just found Valvoline VR1 20W50