Here's an odd one that has just developed -- wondering if it's just a gauge issue, but thought I would ask.

When I bought my truck, the oil pressure gauge stayed pretty much up on the high side (almost all the way up, but not quite pegged). It would drop at idle, but not too much. Now it drops to about half or slightly less at highway speeds (usually above 3000 RPM).

Truck runs very well, no other changes or issues. Only other recent change was the dash panel as I had to replace the back of the instrument cluster due to a little bit of cluster rot. Other gauges appear to read fine/normal.

Does this sound like a gauge issue or a mechanical problem in the works?

Thanks!

 

The only way to really know what's going on is to install an aftermarket mechanical oil pressure gauge, the factory ford gauges aren't exactly known for their accuracy.

 

Like was said above the factory gauges are incredibly goofy sometimes.

Between the gauge, wiring and then the sending unit, who knows what's going on.

You're best bet is to install a mechanical gauge to see what's going on.

Josh

 

once again.........E.manuel!

 

I guess I'm gonna kick this dead hoarse too.
A mechanical gauge is the only way to get a good reading.

Murph.

 

I'd like to add that if you want the most accurate reading, take it at the engine instead of through a capillary tube to a gauge in the cab.

 

Do they have a guage that mounts where the original sending unit is and then runs via wire to a guage you can mount in the cab? Mine is right above the oil filter if I remember right.

 

Are you sure you sending unit is not behind the carb, on the top, back side of the block. Right behind the intake manifold? 1 1/2 round 2" long silver thing with one wire hooked to it?

Replace your factory sensor and while you are at it install a T fitting to go to your aftermarket oil pressure gauge, basicially using 2 gauges. IMO

 

The one down in the front sounds like its the water temp gauge... you want the one in the back, as shown in the pic. Go to walmart, buy a gauge kit for like $10. It will come with everything you need. I checked mine with mechanical one time to see how the factory one read then hooked the factory back up.

 

FE engines have the sending unit on the oil filter adapter.

What I did was to get a "tee" fitting, that way I could still have the factory sending unit and the adapter for the mechanical gauge at the same time.

Josh

 

Here is a picture of mine it is in the front on top of the oil filter, I just replaced it and it appears to work O/K but if I wanted to have both I just need to put a Tee fitting? Bullitt390 do you have a picture? this is a 360 but the 390 seems to be just about the same for most things.

 

My 302's and 390's have had the sender adjacent to the oil filter. I have a T fitting. the straight branch goes to a mechanical gauge under the dash via copper tubeing. The branch of the "T" has a the Factory electric sender for the cluster gauge. The branch/factory gauge doesn't show much variation. The mechanical gauge shows great variation based on oil temp and RPM. I've since gotten electrical aftermarket gauges/and the senders that go with them on other vehicles. The electrical ones are cleaner and work well. If the mechanical one springs a leak, you have oil under pressure squirting into the cab or wherever the break in the tubing is. The latest one I got is in an old Datsun. You get the sender for that gauge, and run a hot wire to the back of wherever you mount the gauge, run a ground wire to a good dash ground point, and wire up the light bulb to a dashlight wire. I buy ISSPRO gauges and senders. I learned about "English thread" with the Datsun, never had an issue with getting the right sender for the Fords.

 

I got my tee-fitting from Ace Hardware, but Home Depot, Lowes and even NAPA have what you'll need.

Josh