Hey all,

My factory oil pressure gauge goes from zero to normal and back and forth depending on it's mood with no in between.

Since it was either all or nothing my suspicion was the sensor (sending unit) was dirty or faulty rather than a serious issue with oil pressure. (thoughts?)

My question is, where is this sending unit located and what is the best way to confirm if it is the problem or not? (replacement info?)

If not the sending unit, it could be the gauge cluster. I do have that known problem of the odometer going dark which indicates a cold solder joint in the cluster. (seen that in the forum sticky. Thanks)

Anything else I should be watching out for here? It has done it for a long time and to my shame I've ignored it. The first time I was in a panic but it came back in seconds. It's gotten worse and I would like to fix it.

Thanks for any help you can offer.

 

After reading more about this I see that it is a pretty common issue and that the "gauge" is just really a positive indicator light and not really a gauge at all.

Will look into replacing the sending unit. Advice? Comments?

 

Good for you.
At least your attempting to help yourself unlike the post above.
All it is is a pressure switch at the oil filter adapter.
Good luck.

 

Any advice on this process?

It seems a pretty straight forward process.

I assume it's drain oil, replace sensor, fill oil, done. Please correct me if I'm wrong.
Some people say that while you're in there replace the switch with a proper gauge. Comments?

I don't see any write ups on this anywhere.

 

Where did this drain oil to change a switch come form?
No need to do that. The oil is down in the pan.
The switch is screwed into the oil filter adapter. It has a one lead connector attached.
.
If you want a gage, there are two choices.
1. A mechanical gauge using an adapter fitting in place of the switch to connect a metal tube to a gauge in the cab.
2. An electric gauge. A sensor goes in place of the switch. One lead goes into the cab for the electric gauge. The gauge needs switched 12 volts and a night light feed from the dash lights.
Take your pick!
Just replace the switch for it's low cost and have it over with.
If the dash has other issues , your not out very much money.
Just get the dash fixed up.

 

Appreciated thanks.

 

Also for future reference there is a TSB that might apply to this situation.
Seems that the sending unit can get worn by the oil drip shield attached to the front axle.
See the following.

Source:
01-4-2***ENGINE - 5.4L - OIL SENDING UNIT INTERFERENCE FIT AT ENGINE OIL DRIP SHIELD - 4X4 VEHICLES EQUIPPED WITH 5.4L ENGINE ONLY

 

Never had an interference issue with the 01 I had. Wasn't even close enough to touch the drip shield. Strange.

 

Well, I replaced the sending unit and it fixed the issue. Man what a hard little piece to get at. Way up past the front differential. I could barely touch it let alone get a wrench on it. But I got it out after some patience.

Also I changed the transmission filter. What a dirty job. Shame they don't have a drain plug. That would have made the deal much neater.

 

Mine was touching. I took the opportunity to trim it back a bit as suggested in the TSB.