DBJoe996

Huh??? Well, whatever.....one cannot measure engine oil pressure at the oil filler cap.
This is the quote from the other thread:
Alright, so- we ran through the basic mechanical stuff because it was ~quick. Then we gave up and decided to check the oil pressure. To do this, I ordered a spare oil filter cap/lid, and drilled and tapped a 1/8" NPT hole in the old one. Not a bad trick if anyone else out there needs to check their pressure without tearing everything apart. - That'll be saved in my bin of "special tools".

jim010

Interesting. Worth a discussion. I wonder if Peter got it to work then. Pressure is force exerted in all directions equally in a fluid in a closed system, so you'd think that pressure could be measured anywhere in the system? I'm just brainstorming here.

Lol, now I want to try it just to see if it works.

Imo000

I know that and that's why I've asked. You should try keeping things in order when replying. You are now quoting a totally different thread.

Imo000

As suggested by others, you should check the pressure where the sending unit is.

DBJoe996

Yes, as I said, from the other thread...the one Jim posted ^^

Mike Murphy

That only works when fluids are not moving (static). As soon as the fluid moves, pressure differs everywhere along the path traveled (infinitely).

jim010

Hmm ... I can see that with a gas, as a gas can be compressed, but a liquid is not compressible regardless of movement? I am not trolling, just brainstorming, by the way.

Don't worry, I am measuring form the spot you all say. But I want to try this out just for giggles.

Quadcammer

Yeah but pressure is just resistance to flow, so in a narrow oil galley pressure will be different than when it floods into lets say the oil pan or even in the large pick up tube

jim010

But resistance to flow is viscosity and not related. Pressure is force over surface area and does not change within a closed system. But if the fluid is separated into different closed systems, then pressure can be different in each system.

Mike Murphy

Gas or liquid, same thing. It’s the difference between static pressure and dynamic pressure.

Dynamic pressure is used to calculate forces when a fluid is moving.

Think of a garden hose that’s 10’ long versus one that’s 100’ long attached to the same valve. The 100’ hose will flow slower than the 10’ hose, even if both have the same 50 lbs or pressure coming from the valve because the overall resistance in the 100’ hose will slow the water down. That resistance is force that counteracts pressure forces.

If the hose is long enough, there will be no water coming out the other end of the hose. If that’s hard to believe, try to image a hose that long and the weight of the water in that hose, and tell me if you think you can push it, pick it up, or even move it. The weight is one problem, but the friction is really the major component.

Mike Murphy

Viscosity is the fluid, but there are other forces at play. And you are correct on the above if the fluid is not moving.