Have a 1997 F150 with the 4.2L V6 with standard tranny. Having a problem with oil pressure. Starts fine and runs fine with no warning lights and the gauge looks fine. However, after maybe 20 minutes of driving or so the pressure drops to near zero and the warning light comes on when you come to an idle or parked. Pressure also drops when you are in gear rolling along but not on the gas. Any ideas what may be wrong?

 

Clogged oil pump screen.

 

I bought the truck as an extra. My Expedition and 350 are killing my wallet on my commute. The 150 is very clean, straight and I figured it'd be a decent commuter as well as a help around my little weekend farm.

Dealer I bought it from said this afternoon that it was a sensor going bad. My BSometer went off naturally. I realize that the dash gauges are almost worthless as far as diagnostics or a true indicator of pressure...far as they're concerned you either have it or you don't.

So am i to assume that because i have an indication of good pressure at speed that the oil pump, sending unit and all wires are good? And for some reason at idle or slower speeds the clogged screen is the cause of low or no pressure?

Thanks for your help...i'm not that mechanically inclined and I appreciate being able to turn to wiser, more experienced minds.

 

FYI-

Just dropped the truck off at the dealer i bought it from. We hooked up the oil pressure test kit and got some really low readings at idle and in the throttle. Apparently I'd been driving around for a few days with oil pressure that dropped to 5 pounds at idle. Not even sure what pressure I had rolling down the highway at speed.

Anyway, they called to say that they were replacing the engine on their dime. I guess enough damage was done that they just decided to start over with a new one.

 

1997 model. new engine? from Ford? no charge???
How many miles are on the original motor?
is this a warranty deal?
Thanks,
BA

 

Am I reading this correctly?Ford replacing a 4.2 at no charge?And,its a 97?It cant be a Ford dealer doing this,right?Thats unheard of!:-staun

 

Well, now my BSometer has gone off.

Dally, where are you? What's the deal here?

 

Let me clear things up...

Bought the truck used and not from a Ford dealer. It's a 97 and had 103K on it when i bought it. It was very clean and straight, new exhaust, brakes, rebuilt tranny and had a new head and gasket. Price was right so I figured why not...

Then the problems started that I detailed above. Given that I had a warranty of 1,000 miles from the dealer he looked at it and decided to replace the engine. I told him that i thought it was the clogged screen as Skoop indicated earlier. But when i called back the next day they said that they were just gonna replace it.

Got the truck back yesterday after maybe 10 days in the shop. Runs fine now. Sounds much better. No oil pressure problem and a 75K warranty on the new engine. Still wouldn't mind knowing what the problem was though. I'll talk to the guy that did the work and let you know.

Didn't mean to leave you hanging...but I had taken the earlier responses as the solution and had not visited the board in a while.

 

I have a well maintained 97 extended cab V6 with the same oil pressure problem, though it started for me around 100K. I had a guy go completely through the lower end. He found nothing wrong, replaced some things anyway (sending unit, filter, pump, etc.) and I started using 20W-50 oil. Several hundred dollars later, the problem is till there. Save your money for now. I'm still searching for a solution to this one. That guy who got his engine replaced is a LUCKY man!

 

Sounds to me like the truck had the dreaded head gasket problem or an overheating problem with coolant in the oil and they patched it up with a head and gasket, Changed the oil a couple times and hoped for the best unfortunatly it didnt last long enough for the "Dont tell the guy **** and hope he doesnt come back pissed for awhile warranty to run out" and they got caught with there pants down and stuck another engine in it so they wouldnt be showing everyone there entire ***. I would make sure they put a NEW longblock in it and not a newer used motor in it from a crashed truck. This is just my gut feeling on this and is what I would be thinking. I have a good friend who does work for used car lots and I get suspicious of used cars because Ive seen the crap that goes on as far as patch together repairs and "rigging". Just my 2 cents. Shoot me if you want to

 

Oh yeah I have a 2001 F150 4.2/5speed with 73,000 miles and no major problems yet except for 1 bad fuel injector, 1 set of tires,1 Quicky front brake job(pads only),1 clutch,1slave cylinder/throwout bearing assembly. Its a sales truck that gets driven everyday around town by several different people in my company. I think its doing ok since its wear and tear items so far and to be expected.. Wish me luck. BigD

 

Had a thought. Bought the truck and didn't pay cash in full. Financed a few thousand just cuz i've got my eye on a tractor as well. Think that may have been a smart move. Figure maybe I got a little better treatment cuz of the note.

Anyway, the engine they put in is remanufactured. Not as good as a new block...but hey...better than what i started with.

 

bought a 97 with a 4.2 brand new 3 miles on it with 5 speed drove it 13000k miles had the recall for the timming cover drove it to 20500k started having the same oil problems for about 90days then it bent a rod because of coolant in the cyld installed a recon from ford. 3 sets of <a href="http://service.bfast.com/bfast/click?bfmid=37919709&siteid=39251846">tires </a>basic mant. what more could you ask for