93 4.9l
normally has normal oil pressure but after driving for over 25 mins or so the gauge will flutter when stopped in drive or reverse. goes all the way down to the lowest end of normal, almost in red. if in park or nuetral its find. and if its in drive/rev i give just a wee little brake tourqe it comes right back up to normal. im running 10w30 and a fl1a. is this oil ok or is it commen for the sending unit to act up like that?

oyea....if i let the it set for a couple of hours and start it back up, its like you jsut changed the oil and it needs to pump up. top end knocks for a second then is perfectly fine. thats the only time it makes noise, never knocks or rattles other than startup.

thanks for any ideas advice or experiences!!

 

the 10s30 and FL1A are good choices. How many miles do you have on this 4.9L? If your cam berings and/or main berings are getting worn you'll loose oil pressure... before we get that far though...

I would sugget you go get a oil pressure guage to test the real oil pressure under the hood. This way you can test oil pressure at start up too. DO NOT trust the dash guage. It's an idiot light that turns on and off when the 5-7psi trigger switch it tripped.

There are 2 solutions to your problem and one involves jumping a wire on the back of the cluster and putting a variable oil pressure switch in (cost is $20ish) or you can get a seperate mechanicle guage and put it on your a-pilar. Either way read this other thread...

https://www.ford-trucks.com/forums/9...onversion.html

 

there are 100,150 miles on it as of this am. it never did this until recently, a hundred miles after i did an oil change with a fl1a and pennzoil 5w30 high mileage, at a friends suggestion i drain and put in 10w30. it used to do it all the time, now just after a extended drive