Oil pressure gauge proper behavior?

[PabloX]

I have an '86 3.2. The oil pressure gauge is essentially always pegged. I assume it's not supposed to be and should vary with RPMs. Any thoughts? Oil pressure sender out of whack?

[Oh Haha]

Yes, the pressure should vary with RPMs, typically 10 pounds per 1000 RPM.

Check the wire connection at the sender. It may just need to be cleaned up to get a good signal.

[PabloX]

Originally Posted by Oh Haha

Yes, the pressure should vary with RPMs, typically 10 pounds per 1000 RPM.

Check the wire connection at the sender. It may just need to be cleaned up to get a good signal.

Thanks. I'll give that a look.

[bickyd]

From my original manual. the oil level gauge indicates the amount of oil in the oil tank. If the needle is in the white range while on level ground with engine at idle speed and the oil at operating temperature, there is sufficient oil in the tank. the oil level cannot be determined while driving and slight movement of the indicator needle is normal. ( this is the gauge with the fuel gauge.) The Druck pressure opposite of the oil temperature gauge says that you should have at least 3.5 bar at 5000 rpm of the motor. hope this helps.

[gazzerr]

If it's pegged I think that suggests a grounding issue. It's either the wiring or the sender itself contained in the oil tank behind the passenger side rear wheel.

[PabloX]

Originally Posted by gazzerr

If it's pegged I think that suggests a grounding issue. It's either the wiring or the sender itself contained in the oil tank behind the passenger side rear wheel.

Well, I'm talking about the pressure gauge, not the oil level gauge which works well.

I'm going to check the grounding on the oil pressure sender. Thanks.

I should also note that pressure doesn't go up when the ignition is on, only when the engine is started. I'm not sure that's consistent with a wiring problem or not.

[GeorgeM]

I've found 911 oil pressure senders are almost consumables. Barring a wiring issue, if it's the original sender, it's probably time for a new one.

I'll also pass on that some of the cheaper aftermarket units aren't worth the savings.

[gazzerr]

Apologies I should have paid more attention when I read that! I think it's still a grounding issue that causes that (either constantly grounded or no ground at all).

Research before you attempt to remove that sender. You can do major damage to your case if you don't approach it in the right manner.

[PabloX]

Originally Posted by gazzerr

Apologies I should have paid more attention when I read that! I think it's still a grounding issue that causes that (either constantly grounded or no ground at all).

Research before you attempt to remove that sender. You can do major damage to your case if you don't approach it in the right manner.

No problem. Do you think a grounding issue would cause what I described above about the difference between ignition on and engine running?

I have a leak around the sender so I think I'm just going to replace the whole thing (and clean the contacts while I'm at it) like George recommended.

[James Brown]

changing that switch can be nerve racking due to several factors. don't shear off the big banjo bolt that holds the angle bracket to the oil gallery. Check all the connections and clean them with scotchbrite. Even on the dash gage side. sounds like a sender.

[gazzerr]

Yes, when you turn the key to on you are powering up the circuit for the sender that drives the gauge. The needle will jump up a bit from it's stop to the "0" mark.

It measures oil pressure so the normal behavior is as you crank the motor the oil pressure will build up and the needle will start to rise (and the idiot light will go out) up to the 1 and above mark. When the motor fires you should see the needle hovering around between the 1 and 2 mark (I assume it's bar). When you rev the engine it approximately matches the rpm/1000 like Oh Ha Ha said. When you are cruising on the freeway you should be seeing the needle around the 4 mark. At least that's what mine does.

[Reiver]

Pull the gauge unit and clean the connectors...prob a ground issue at the gauge.