I have a 88 full size Brono with a 5.8 engine. I am havin probs with my oi pressure, i changed ol (with an engine cleaner) but when I first start it the pressure is at 55psi, but after it warms up the pressure drops to about 20psi. Any suggestions???Thank YouChris

 

If your readings are during idle, they are normal. As the oil heats up and thins out, a drop in pressure always results. If you have 20 psi at high rpm, the problem is more serious. Need to check oil pump/pickup screen than bearings. Should have about 45 psi at 2000 rpm.

 

until this past jan i had an 87 with the 302 and it to had only a little oil preasure (16-18 @ idle in neutral and it would drop between <10-12 @ speed and around 2000 rpm after taking in it to 4 or 5 garages all of which could not say what was wrong without pulling the oil pan -- this was expensive because (600-800 dollars) they all said they would have to lift the motor at the time I did not have that kind of extra money so i desided to try some synthetic oils -- rather new at the time (early 90's) with 12lb of oil preasure and over 195,000 miles i retired it when due other problems with the body and such is was sent out to pasture... of course it has been replaced with an all red 1996 bronco and i drive this one till it;s time is up. BUT as the years wore on i began to swear more and more that CASTROL SYNTEC was magic. I remember once i took it if to get a new exhaust put on and the garage was doing a promo that with any sarvice work they would change your oil for free ( i found this out after the fact) as i drove the truck home -- a monday -- i could hear the motor ticking i new it was time to change the oil i actually had the oil in the back but it had rained that weekend and without a garage i not big on laying in puddles so i put it off. By thursday i had driven less than 200 mile the ticking was so bad i change the oil during my lunch time in the parking lot at work, that;s when i noticed the genaric oil filter i call the garage and they told me the had changed the oil. when i drained the oil it was black as the ace of spades and ran like water. i put the syntec oil back in.....POOF.....the tickin disapeared and the truck was back to 'normal'. It now runs in all my vehicles --
a RED 90 ford probe
a RED 96 ford bronco
a RED 59 ford f-100 4x4
a RED 83 ford escort (enduro car)

just my thoughts...

 

Howzit going, Chris...I wouldn't worry too much about the pressure in your motor (providing the pressure readings are at idle). I went through the same thing with an older 5.0. During morning start, the pressure would be 35-40 psi, and when it warmed and ran for a bit, idle pressure went to 15 psi. Believe it or not, the pressure you got is okay. Normal idle pressures in stock motors can be as low as 10-12 psi. That came from FORD. I felt that was too low for my taste, and I installed a melling high volume oil pump. Now, my idle pressure is about 35 psi, and pressure at 2000 rpm is about 75-80 psi. Keep in mind this is a freshly rebuilt motor. Good luck!

 

The oil pressure gague in my '88 f-150 (351w, 110,000) has been torturing me for a while now. I just have the factory in dash gague, but if its acurate at all, i'm getting some pretty low pressure (the needle almost never reaches the'N' in normal). I thought it might be the sender or the wire, i checked the wire, and found that it had been touching something hot enough to burn almost all the way through the wire (the service manual calims the system works on resistance, so frayed wires should have skewed readings)....so i fixed the wire, which imporved my reading for a little while, but it went back to its old tricks, and i checked the wire, which was still together...so i changed the sender with no luck. I read somewhere that the in dash gagues aren't really gagues at all, but just read a cetain level when the pressure is above a certain point and a different level when the pressure is below that point. Has anyone else heard this about late 80's to early 90's fords? I think i'm gona get a $20 sunpro mechanical oil pressure gague before i go crazy.

 

ooooh...ouch....you don't have any problems with leaks do you? I've been told that after an engine has been run for a while with regular oil, then many miles down the road, a synthetic is put in, that it will find every little pinhole there is that the regular oil won't find....it's ok to to use the synthetic from the start, but not after many miles have racked up.....at least this is what I've heard.....any ideas in this?

 

I found the same thing. My 5.0 had 150000 mi on it when I made the change. I developed a lot of leaks but a wrench on the oil pan and valve covers seemed to correct most of it.I'm still using synthetic I "think" the engins runs easier.

 

i have an '87 bronco, i feel your pain!! I have recently put a new reman motor in it..I'm no expert but from my experience your bearings have are worn out. try putting some 50w oil in it if that does the trick keep running it. the fact is that most 80's fords are running around with no oil pressure but their owners just don't care.