oil pressure reading

[burt ragio]

Today I installed a few items electric autometer transmission temp & oil pressure gauge & sendind unit. Upon start up the oil pressure needle read 95 psi at idle air temp apx 65 degree. Drove it around the block & upon return at idle it dropped to 55 psi. How do I check wheather it's a bad gauge or sending unit ?

[fastblackmerc]

Normal... nothing wrong...

Mine reads 100+ at idle when cold, 25 or so at idle when warmed up.

[bigmerc'03]

electric ones suck!!! get the real working one the mechanical one

[red]

Just an FYI, I've gone through 3 sending units for the Auto Meter Ultra-Lite Oil Pressure Gauge (#4327). I contacted Auto Meter about the problems, and they stated that the short-sweep versions have a sending unit which breaks with excessive vibration. They suggested either upgrading to the full sweep, which has a much better sending unit, or to do a remote mount, for which they sell a braided hose. I was annoyed by their answers, particularly the fact that they sell a product with an inferior sending unit (they even went as far as saying that it is a known problem on 4 cylinders, since they typically run rough) and apparently provide no application notes addressing the issue. Anyway, one time when it went bad, the values were shifted (15 became my new low pressure, and 75 or so became my new high pressure). The other times, it had no reading. Again, just for your information. However, I don't think you have a problem.

[burt ragio]

Fastback, Red, thanks for your reply. I'am pissed spent time and money for what ? garbage. They don't read true I mine as well left the oem gauge in. I will be on the phone tomorrow with autometer.

[bigmerc'03]

mechanical ones last longer had mine 4 about 3 years no problems

[RF Overlord]

burt, before you panic, a couple of things:

1.) The oil pressure readings you're getting are perfectly normal. Anyone with a real functioning gauge of either type will get the same readings.

2.) I've had my AutoMeter electric gauge in the Blackbird for 5 years and had NO trouble with it. When I replaced the Ultra-Lite with the U-L II, I swapped senders and put the first set in Phoebe over a year ago and it's still working just fine.

[Dragcity]

I have a mechanical gauge and I get 95 to 100+ depending on ambient temps at initial cold start-up. MOst folk s wiht the electrical say they are just as accurate. I went mechanical because I think the likelyhood of an electrical sending unit going bad is grater than the mechanical moovement of the needle going bad....

I like my mechanical one....

I don't think you readings are incorrect.

[burt ragio]

Thanks for the info. I guess I'am just not as savy to correct oil pressure readings as I thought I was. I have a lot to learn. Hard to believe pressure can be so high upon start up with warm air temps.

[RF Overlord]

That's because oil doesn't care what the air temp is. Oil pressure is determined by engine design, bearing clearances, and the temperature (and viscosity) of the oil itself.

[Aren Jay]

This is why Mercury put the dummy gauge in.

[RF Overlord]

That's exactly right...