Did you know that Ford has been duping us for a long time. The oil pressure gauge in most Ford Truck and Cars manufactured since about 1986 has had a "Fake" oil pressure gauge. The gauge is drive by a switch which switches on at about 4.5lbs which ties to a resistor that causes the gauge to deflect to about 2/3 scale.. I was totally unaware about this when I bought my new truck. I sent ford a complaint and they said basically "It's designed that way and we aint gonna fix it".... Below is a link to a site that details this scam... http://www.asashop.org/autoinc/march98/techtips.htm


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99.5 F250 SD Powerstroke

 

When I found this out a while back, I was thinking of getting a dakota digital oil pressure, cylinder head and transmission temp guages. Anyone had any experience with the Dakota Digitals and the difficulty of wiring ?

I know they basically made for street Rods but understand they will work on Late models as well

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99 F150 5.4 4x4 ORP 3.73 styleside deep wedgewood blue ..no mods (yet)

 

I totaly feel dooped. I always wondered why the oil pressure didn't increase w/ engine rpm (like a real gauge would)
Now I have the answer I din't want to hear.
Maybe if enough of of F150online members make a stink about FORD will do something.

 

New Truck, 54regcab,

Not only the oil pressure gage but the voltage gage is the same, an idiot light with a pointer.

I didn't know this either until last Jan or so when I got "clued" in here.

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Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK. Man, I got it all!

 

I don't know about 97-99, but my 93 F150 has a "for real" voltage gauge. it has the oil pressure idiot gauge. The Ford diesel site has some info on how to convert the idiot gauge to a real gauge. The way the idiot guage works is there is a pressure switch on the engine that closes at around 3-5 psi. There is also a resister in the circuit that reduces the voltage and causes the gauge to be in the middle of the scale on the instrument panel. The gauge could probably be converted to a real gauge. In fact on the earlier models, such as mine, it appears to be as simple as buying a pre 1986 oil pressure sending unit for the engine. For the later models, some sort of adapter would be needed to attach the sending unit to the modular engine and research to identify where the resister in the circuit is located. If the resister is located in the sending unit (as it appears to be in the pre 97 models) then all you need to do is to adapt an earlier sender to the modular engine.

The reason Ford went to the idiot gauge is because so many real idiots took their vehicle back to the dealer complaining of "fluctuating oil pressure". A TSB was issued around 1987 on how to convert a real gauge to an idiot gauge for people with these complaints.

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'93 Regular Cab XLT Shortbed, 5.0, K&N, Borla, 160,000 miles; Future SuperCrew owner.

 

Aw gaudenti, please don't tell me I pulled another "Fuel Door Light" ........

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Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK. Man, I got it all!

 

"Fuel Door" light? Oh, you mean the light on the instrument panel that lets you know if you left the fuel door open?

 

I thought the voltage gauge was real. I checked when I first heard about the fake oil pressure gauge. I turn the key to "ON" without starting the engine and noticed where the voltmeter pointed. Then I watched it as I cranked and started the engine. It went down while cranking and then up above its initial position once the engine was running. That seemed like it's acting like a real voltmeter. I'll look at the schematics when I get home tonight to see if they tell us what's going on.

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Danny
'98 F-150 Std., RC, SB, 4x2, 4.2L, 5-sp, 3.08, AC, speed control, rear slider
with Syntec engine oil, MTL trans fluid, Edelbrock shocks, 50 Series Flowmaster, K&N with airbox mod, electric radiator fan


[This message has been edited by gaudenti (edited 08-02-1999).]

 

The oil pressure guage is an on/off only. Also, you can't change it to make it real on a 97 and beyond F150. There is no resistor on the cluster that you can clip out. The resistor is part of an IC in the cluster.

The voltage gauge is real however. The oil pressure gauge is "fake" because most people don't know how to read it and it was casuing false warranty claims. This costs Ford big bucks. Oil pressure is not a function of oil level. You could have only one quart of oil in your engine and still have proper oil pressure.

 

Idiot question: Why put in a gauge that does not work? Why not just put in the idiot light? I thought the gauge was real!! Now which part of this truck is an idiot!?!

Any other gauges that don't work the way you would expect? The Tach and Speedometer work don't they? They appear to change as I'm driving. Just want to make sure!!

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1999 Ford F-150 XLT Sport 4x2 SC; Black, Med Graphite Interior, 5.4L, 3.55LS, 17" Wheels, 275/60 Tires, Tonneau Cover, Captains Chairs, CD Changer, Heavy Duty Electrical and Cooling, Nerf Bars, Rhino Liner, Tinted Windows

 

gaudenti,

Yep, that's the one. My volt meter must be hooked up to that the "Fuel Door Light," it only changes when I put my seatbelt on.

Sasquatch,

Know a way to check your speedo for sure? Run through a radar trap at a 100 mph ...

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Dunbarton "The Middle Aged Kid" '99 XLT SC SB 4x2 4.6 auto 3.55 ls The occasional Z-71 Eater! Wedgewood & Denim, SuperChipped, Airaid FIPK. Man, I got it all!



[This message has been edited by Dunbarton (edited 08-03-1999).]

 

Tim A is right. I was once 4 wheelin in my '85 blazer and a twig broke the seal on my oil filter..dumped it. My guage never moved.



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99 F150 5.4 4x4 ORP 3.73 styleside deep wedgewood blue ..no mods (yet)

 

Dunbarton,
I'll give that a try unless you have already done that as a service for the rest of us!! Where does that top speed limiter kick in anyway?

Really is kinda upsetting about that oil gauge though!!

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1999 Ford F-150 XLT Sport 4x2 SC; Black, Med Graphite Interior, 5.4L, 3.55LS, 17" Wheels, 275/60 Tires, Tonneau Cover, Captains Chairs, CD Changer, Heavy Duty Electrical and Cooling, Nerf Bars, Rhino Liner, Tinted Windows

 

While I woudn't put it past Ford to do something that stupid, I do believe that the gauge on my old 98 4.2 was a working gauge.
It did fluctuate during highway blasts at high speeds/RPM's. And immediatly after an oil change it registered 0 and then waited a few moments to respond as would be expected. Are all the oil gauges allegedly idiot lights?

 

The cluster in the F150 is the same type as the one used on all Ford full size truck and vans. So, the design is common across all the trucks to save us money. Maybe the super duty pickups have a functional oil pressure gauge. So they need the needle, and the light duty gets it to keep the design the same. Plus it looks nice.

If the truck gets a break in the line, that would be a total loss of pressure, which the needle should have detected. My point is, low oil levels do not always mean low pressure. Most people have no idea what it means if their oil pressure needle moves while driving . Because of that, we fixed it in place unless there is a problem, then it will drop to zero.