Ford Oil Press "Idiot" Gauge

[blkfordsedan]

I found this interesting tidbit on the Ford truck forums while researching an OEM tach cluster swap. I thought there may be a lot of us on here that have late '80s to early '90s Fords. I always wondered why oil pressure gauge always reads the same (even at a hot idle).

http://www.rowand.net/Shop/Tech/FordOilPressureGaugeFix.htm

IMO, anyone who is concerned enough about actual oil pressure should install a mechanical aftermarket gauge with real numbers on it anyway....................

[leapin]

You'd be surprised how many cars out there are like that. Miata are a good example. The first few years were a true gauge but they switched and now switched back. I get countless questions now. "My brand new miata with 50 mi. on it has oil pressure issues the guage moves down at idle" I think companys did it because there are to many idiots out there who cant figure out the speedo let alone the oil pressure gauge.

[Tim]

Very interesting. That would explain nicely why my roommate's '70 F100's oil gauge reads so low, despite the engine being practically new.

[Tim]

Volvo did the same thing with their temp gauges. The needle will sit at exactly half and not budge unless the car is overheating.

It really weirded me out when I owned a 740. I liked having a gauge that would move so I could monitor the engine temperature.


-Tim

[Festy46]

I have an '86 with a 460 and I noticed the oil pressure gauge dropped almost to "0" at highway speed one day. It scared the crap out of me and I pulled off the road immdeiately. I checked the oil on the dipstick and it was full. I got back in and started the engine and the gauge registered half way up at idle. Started back down the road and the pressure stayed up. It still does it sometimes, but now I just ignore this "Ford better idea".

[TominMO]

Very interesting. That would explain nicely why my roommate's '70 F100's oil gauge reads so low, despite the engine being practically new.

That may not be the reason. The article talks about 80s and 90s Ford trucks, not 70s.

[FB71]

Ford started the practice in 1992 on F-series trucks, Broncos, Crown Vics, and E-series, and '94 in Mustang.

It was exactly for the reason suspected; customers would freak out if the gauge moved at all. Nearly all EXPECTED the needle to stay in the center while running. So Ford gave the customers what they wanted.

We actually had to retro-fit the '95-'97 Contours, because customers complained that the Temp gauge would move...

[Festiva_tunner]

^ priceless - the customer is always right . . . Stupid but right lol

[FB71]

^. . . Stupid but right lol

bingo.

[blkfordsedan]

Jim, are they still doing this? Do you remember what years/models have the added resistor and which ones have the circuit designed this way? Isn't there a test mode on the newer instrument clusters with digital odometer that will display the actual value of engine parameters (like rpm, temp, oil press, etc) from the ECU?

Actually, I think the "go/no go" operation is probably the best set-up considering the general public. I wasn't like Ford was trying to hide oiling system problems. Besides, when all you have is a "L" and an "H", a moving needle doesn't tell you a lot anyway.