Hello all. I have a 98 4.6 with 130k on the engine. when I get off the highway and wait at a red light oil pressure drops to 0. I have relpaced the oil pres, sensor (on/off switch) with the napa (better than the original ), and the $44 motorcraft version. Still no pressure after hwy driving. No knocking or ticking (yet). I run m1 ep 5-30. Is it time for a new oil pump? If so can someone recommend a parts lit and anything else I SHOULD replace as long as I'm tearing off the front of the engine? Motorcraft oil pump? High flow oil pump?

 

The mod motor oil pump is pretty bad *** they rarely fail. I'd drop the pan and see if the screens gunked up first..

 

Put a gauge on it and verify the oil pressure a second way.

If it reads low, do what jethat said: Drop the oil pan and check the oil pump strainer.

 

Yea, they won't run to long IF you use additives in the crankcase.

Also, - They can go for a good long time without changing oil. BUT, - if you get maintenance bug up the wazoo one day and its been, ohh, 20 or 30,000 miles since you were last infested, she just may blow within 800 miles or so and right after the new stuff went in.

Know Y ?


Seen that to many times. Divorcseize/Single women do that all the time.

 

So during hwy driving, your oil pressure is in the "normal" range, but at idle it drops to 0? Does the pressure jump at all when you rev the engine?

Maybe there is some kind of blockage at the pickup. When under load, it seems theres enough force to pressurize the oil passages and sensor. But when no load, there's just not enough suction to prime the pump?

Sorta like when a fuel filter/sock gets clogged. There's enough fuel being sucked up under acceleration or revs to run the engine, but not enough while at idle and it dies.

 

[QUOTE=OldeIron;4991384]So during hwy driving, your oil pressure is in the "normal" range, but at idle it drops to 0?

Exactly, only after I have been on the hwy for 20 min or so, get to the red light at the end of the exit ramp and no pressure. Needle bounces. If I just touch the gas it comes right back. Driving around town, no problems. only after hwy driving I ave problems. I put 10-40 in just for now until I (we) get this figured out. Tried to drop the pan today, snapped 1 pan bolt and rounded another, out of the four I tried. They are seized. Motor mount and trans mount bolts came out like butter, go figure.

 

JBrew I knew a guy that would NEVER change the oil in his Lease vehicles, but I'm not one of them. I've treated his truck very well and find it hard to believe that there would be sludge anywhere in this engine. Additives are a waste of money imo.

 

You can't run 10w 40 in that engine without starving certain internals of lubrication. Friction, heat come quick, it tears them up. Doesn't take long either.

 

So I have to choose between 0 oil pressure or too thick an oil? sounds like a loose -loose situation

Bottom line is I have to get this pan off, but I cant keep snapping bolts. would a dealer loosen them up? Auto rx?

 

I'm not sure what you mean? I was talking to someone else.

 

I'm saying that I don't want to run it with no oil pressure at a red light, and you're saying that 10-40 is bad for my engine, but I have to find a happy medium until I find out what the problem is . I thought that thicker oil is better than low oil pressure temporarily. Btw is everything metric on this truck?

 

You have a major issue that unfortunately there is no happy medium fix for. The truck should be all metric. Unless people put on standard bolt stuff..

 

Yes, 10 w 40 is very bad for the modular engine. In fact, the first thing that happens with 10/40 is the heads fall apart lol. The followers fall off, then, no compression. Once your at that point, - damage is done. Unrepairable.

Using thicker oil is VERY old school thinking for old style push rod engines. You don't have that type of engine in your Ford. Thicker oil use to help quieted down a push rod engine So did adding a little saw dust, - an old trick before selling a vehicle with a noisy engine. Running thicker oil never really helped with oil pressure with any automotive type engine. That was a merely a myth conceived around the bon fire.

 

With all due respect, When Ford said to run 5-20 I switched and had the same oil pressure problems. Then I wet back to 5-30 and my problems went away until 3 weeks ago. put 10-40 int it and no oil pressure problems. I understand that these engines are tight and require thin oil. I'm going to have a shop work on these pan bolts this week and we can see what going on in there . Do I put the 5-30 back in?
Please don't take this as argumentative, I don't mind taking advice from people that actually know something

 

Then run 10w 40 if it solved your problems.

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