I just noticed today, that when my truck is idling the oil gauge sits in the middle of normal. If I drive or just sit in neutral with my foot on the gas, the gauge will go down almost past the L. When I let off the gas, the gauge goes right back up to the middle. I am hoping this is some kind of problem with the switch? Where is the switch located on a 460?

 

It is located on the back side of the engine just below the intake manifold it has one wire hooked to the end of it and looks like a bell. Hope that helps

 

Check the wire connector and be sure that it is clean. You might have a ground strap problem between the engine and the frame. Are your motor mounts OK? I've seen bad mounts allow the motor to move enough to pull on the wires.

Good luck!

 

I went to get a new switch today and it doesn't look like the old one. The old one is the silver bell looking one, but the new one has a silver base, but the top half is a small grey plastic cup. It still hooks up the same way electrically. The other difference is the end that goes in the motor, the old one has a small hole, and the new one has a big hole. Could this make any difference in the way it works?

 

It could make a difference on how the gage reads. When I got the engine for my truck the sensor (switch) had a big whole at the base and it did not read anything on the gage, the sensor on the. I got a new sensor, and it did not work, then I used the switch from the engine that was originally in the truck, and the gage worked, the only differance was that the whole at the base of the one that works, was smaller than the other two sensors.
So I suggest putting the new sensor in, and if it does not work, take it back and along with the old one, and tell the parts dealer to look up another one, they might not have gotten the year or engine size right.

Also if the engine is not the original make sure the dealer is looking up the year of the truck, and not the year of the engine.

 

The new one that you got is a pressure switch for a truck with an oil light, not a sending unit for a truck with a guage.

 

Parts dealers tend to get these parts mixed up from the oil sending unit to the oil pressure switch. I've had it happen to me even with the old one in my hand and arguing the point out to autozone that there computer is wrong finally I just went to Napa auto parts and got what needed, little further from my house but worth it. Less

 

Yea, we have a auto idiots (autozone) by our house. Aouto idiots is usually cheaper, but the Napa workers know what they are doing. 2 weeks ago when I put in a trans and front strut plats on my uncle's car, auto idiots got all 3 trans seals wrong, they got the rear engine main seal wrong, and they also got the strut plates wrong. So we had to go 2 towns over to get to a decent parts dealer.

 

Eh my oil gauge is also messed up it reads no pressure but like the whole side of the cluster doesnt work, no gas gauge,oil,temp,voltage there must be a short somewhere cause it all seems to be fine, but yeah i havent had anytime to go thru and tear it apart, good luck with your problem


Napa Around here BLOWS CHUNKS lol it takes them for ever to get a price and half of the time it is wrong, but then again they are all morons around here, autozone isnt actually to bad around here, usually they get it right just my opinion :P

 

Hey F-100.

Check the fuses first. Did it work when you got the truck? The ammeter should be working as it is not controlled by the same circuits that control the other gauges. The regulator that controls the temp, oil, and fuel gauges is up behind the dash on the back of the gauge cluster. It regulates the 12v line down to about 5v.

Back to the topic:

When replacing parts, be sure that the replacement looks just like what you are replacing. The gauge sender on the engine is totally different between the dash light version, and the gauge.

I've had NAPA sell me the wrong parts before. YOU need to be the one telling them what you want. They dont have a crystal ball back behind the counter, that I know of. All versions of our trucks are very different, as I am finding out, and even dealer parts can be different from truck to truck.

Good luck

 

I thought maybe the PO had put in the wrong switch. But I guess I just got the wrong one. Oh well, I will go exchange it as I have not had time to install it yet. Thanks.

 

HAd a couple mustangs and a 91 explorer at one time, seemd about twice a year I would have to replace the oil pressure sending unit because it would read low pressure, and it would indicate that pressure dropped as rpm increased.

 

I got the right sending unit this time, turns out the guy looked up a 95 instead of an 85. I installed it today, and now when I sart it, the gauge will practically max out. Haven't got to drive it yet, I am gonna take it to work tonight and see what happens. I will eventually get a brass T fitting and run a mechanical gauge though. Better safe than sorry.

 

when the oil pressure is getting very low do you ever hear any of the lifters start to clatter ? If there is a lot of milage on the engine it might be time to pull the pan and clean the screen . While your at it drop in a new oil pump .

 

Stcostang67, I added a mechanical oil press gauge to my 86 also. The factory gauge reads anywhere between N and M at any given time, but the mech gauge always reads 50 psi running down the road and 30 psi at idle. I agree better safe than sorry.