1997 f-150 oil pressure gauge bouncing
 

I have a 1997 F-150 I just purchased the oil pressure gauge goes up and down, when it idles the hand shows low, when I press on the gas it goes up to past middle and high. When the hand shows low the oil light comes on, it looks like maybe an oil temp light? Does anybody know what I should do?

1997 F-150 oil pressure gauge question
 

I have a 1997 F-150 I just purchased the oil pressure gauge goes up and down, when it idles the hand shows low, when I press on the gas it goes up to past middle and high. When the hand shows low the oil light comes on, it looks like maybe an oil temp light? Does anybody know what I should do?

The light is for low oil pressure. You may want to check the dipstick to see if there is enough oil in the truck.

oil pressure
 

i checked the oil its full

btw i checked the oil its full

Change the oil pressure sending unit. Sometimes they get clogged up and give false readings.

Then there are, perhaps, other mechanical issues causing the low pressure problem. There are some good mechanics on here and I am sure one of them will be able to make some good suggestions as to where to start looking for the problem.

Put a mechanical gauge on at give us the readings. The one you have is electric and subject to be wrong.

Sounds like the new pressure gauge is doing just fine. Pressure will increase with egine RPM. Problem is at idle. Is idle speed normal? Am hoping its not. With oil level normal the lite is warning you of low pressure. Is there any lifter noise when lite is on? Another question, what engine and how many miles?

If the oil pressure lamp is on when the engine idles and there's enough oil there are 2 ways- low viscosity oil e.g. 0W 30 SAE on summer, or you may have major engine problems. Could the engine be overheated?

Hello All,

I have a 1997 F-150 standard trans., V6 with 95000 miles. I just had my oil changed last week (put in the 5W 30 SAE) and have been experiencing the "oil pressure gauge bounce" ever since. If I take off and go highway speeds, it stays at a consistent medium reading. However, as I get through stop and go traffic in town, it plummets to low, or even nothing - flatlined. Is it the summer heat? I drive 30 miles to work in morning and return in the evening.

Curious to know if I should consider this some impending doom for the engine...

Hello and welcome. You've put a winter low viscosity oil into your engine. Replace it with ... i think 15W40 or 20W50 will do fine.

http://www.valvoline.com/carcare/art...1ov&section=hm

Been There, Done That!
 

I had the same problem, eventually it did not have any oil pressure, and the lifters pumped down and chattered in protest. Basically the top end is not getting oil. Forget the oil pressure sending unit, the tappets tell the story. Oil is not getting to the lifter galley and into the lifters, so how? Hard sludge is most likely your enemy.

I keep my engine clean, inside and out and full of good synthetic oil, but over the years the carbon blow-by will settle in areas that are not oiled with pressure, like the lifter galley.

Oil leaves the oil pump and is forced through the crank oil holes to oil the mains and connecting rods, then it is directed up to the top of the heads to oil the valve train, then runs down into the lifter galley, here it is pooled to keep the lifters full and then drips down past the cam and into the pan. The oil pump sucks the oil through the screen and pick up tube, then through the oil filter then past the oil pressure sending unit and into the crank holes again. These small crank holes create back pressure which the oil sending unit registers as oil pressure to the gauge.

This may sound like auto shop 101, but you need to understand this perfectly to diagnose an oil pressure problem.

First drain the oil into a clean metal tray, pour it off and look at the bottom. If you see fine metal glimmers, it is most likely the babbit surface of the mains and cam bearings. This means the oil is not leaving the pump, hence the valve train is starved and so the lifters which tick when they pump down, or run out of oil. If there is no presence of this fine metal, then the oil is most likely getting through the crank and up to the valve train and into the liter galley. This is a great place for carbon to separate from the oil and build up into a hard sludge. Eventually it can close off holes and block oil from filling the lifters, hence the lifters start tapping, usually one or two at first.

So the oil pump is almost bullet proof, so it is usually not the problem, but to make sure you can pull it in 20 minutes and use a feeler gauge to check its tolerances. The specs are in any Chilton or Hayes manual. If there is no scoring of the internal aluminum casting from the pump gears, your oil pump is fine, mine was fine. This is a positive displacement pump, so it can't pump if the intake (oil pick up tube and screen) or any passages after the pump are clogged. The cam drives the pump with a gear and shaft, if this is broken you would know it, plus lots of big metal pieces in the oil.

So to check the pick up tube and screen, reach in through the drain hole with a coat hanger bent so you can feel around. If the tube is loose, you can feel it. Next with the pump off, spray degreaser through the intake port in the timing chain cover (this is in the aluminum casting the oil pump bolts to). If the degreaser runs freely out the oil drain hole, the screen is not plugged, if it is plugged this will clean it without pulling the pan, which means pulling the engine on our trucks.

So if it's not plugged the blockage must be on the other side of the pump. This is a little more difficult to diagnose. Pull a valve cover and look at the valve train. If there is lots of gunk build up, then you can imagine what the lifter galley looks like. This is what my problem was. So then put it back together and fill it with very thin engine oil (15 wt. diesel oil is good) along with a quart of engine flush. I suggest letting the engine idle for a long time, rather than driving it and putting heavy loads on the engine. If you are lucky the gauge will show pressure all the time this is running and the lifters should pump up and stop ticking. Don't get too excited yet, if the engine has ever gotten hot or you missed allot of oil changes, or it's just old like mine with 150,000 miles, the passage ways may not clean easy, if at all. Drain the oil and look at it, if it's dirty, do it again and as many times as it takes to start getting clean oil. The option is to pull the engine and pull the pan and intake manifolds, manually clean the lifter galley and lifters, check the main bearings etc., etc. Yuck!

It is always best to replace the stock oil sending unit with a mechanical one and gauge, at this point you don't need to install it in the dash, just set it where you can watch it throughout these tests. The fitting just replaces the electric sending unit (which is just a lousy switch that closes and provides a circuit to the gauge at about 15 psi, it's not proportional and will not vary with small pressure changes, basically it's just an idiot light) with a metal tube coming out of it to the gauge; a real oil pressure gauge!

I have been working with engines for 40 years and have never seen one that collects gunk like this one, it's a design flaw, basically it's a big sh*t sandwich and we are all going to have to take a bite!!

I pulled my engine, cleaned it, replaced all the bearings and put it together... runs great with lots of good smooth oil pressure and she'll go another 200,000 if I change the oil every 3,000 and don't let it sit for long periods with dirty oil in it, it gives the carbon time to separate.

Good luck!

Mark

Nice write up Mark, suggest you think about doing a similar write up in the How to section. We need good knowledgeable people around here to help us less informed around an engine. :thumbsup::thumbsup:

great write-up Mark - just to be clear are you saying that the 4.2v6 has oiling issues or are you speaking about one of the v8's?

No V6 Oiling Problems Known
 

As far as I know there are no oiling problems with any of the Ford truck engines.

The problem I found was carbon and filler separating from the oil while using an oil for high milage vehicles. These oils have a "filler" in them to increase compression and help stop minor oil leaks on old engines. However it can separate easily... I DO NOT recommend ever using this kind of oil! It adds to major sludge problems. Live and learn:blush:

Mark

Great info Mark. I have a '97 F150 v-6 with 145,000 miles and I love it, but...... The pressure problem with the gauge fluctuation with tappet clatter arose the other day. So,I gave $145.00 to a mechanic to flush the system and do an oil change but the condition reappeared the next day. It usually rears its ugly head after I've made a u-turn or just a hard turn after I've been driving awhile. I'm assuming it could be some sort of transient sludge that sloshes about in the pan preventing proper circulation. I have just enough mechanical skill to possibly get into trouble while attempting your recomendations, but also not quite smart enough not to try.

Bouncing (or no) oil pressure!
 

Hi fellow 4.2 owners with bouncing (or no) oil pressure!

There is another- more disturbing problem that can affect our oil problem, but it would be the last place I would look! This engine has a known problem with the lower intake manifold gasket coming loose and leaking coolant into the oil. Now I know all you pros out there say "just check the dip stick or drain the oil and look for coolant bubbles". That's what I did, and as most of you have found, there is nothing, but after I bumped into a long thread on this site about the intake manifold problems hundreds of people have experienced, it all came together.

The intake manifold gasket leaks just enough to pollute the oil, more of a seepage. You may have noticed that the coolant slowly disappears, but there are no leaks, this is the first sign of the problem. Coolant seeps into the oil which along with other things can coagulate the oil into sluge which will not drain out with an oil change and the first thing to clog is the oil pick-up screen; YEP! See the pic of the one I had.

It was so bad that I couldn't clean it enough, so I replaced it ($25). Of course I had to pull the engine to get the pan off, that's the catch! However in doing this I found that you can get the pan off and change the tube with the engine part way out. Use common sense and a good hoist. Pull only the things necessary to lift the engine high enough to get the pan by the cross member. Take pix of every plug and hose you have to remove to get the engine just raised enough to clear, but don't unbolt the tranny or you might damage the input shaft. I was surprised I was able to lift the engine that high without the upper intake manifold on, the tranny will just rotate as you lift... just don't force it!

Once that's replaced, you can now remove the lower intake manifold and install new gaskets. NOTE: while removing the bolts, you will probably notice some are loose- way below torque- BINGO! At this point consider yourself lucky as many people have had a big enough leak to suck coolant onto the cylinder and BANG!!... hydraulic lock, bent rods etc., etc.

So the moral here is to watch the coolant level like a hawk! It should only use about a cup between oil changes, if it drops all the way to empty, it's time to fix NOW! Don't be too bummed, I found the engine in rather good shape, strong pistons, still honing marks in the cylinders, cam and lifters all good, along with the main and con-rod bearings, all good etc. At this point if you want to pull the engine and rebuild it, all you need is to replace (or have replaced) the cam bearings, main, conn-rod Bearings. Hone and new rings. You may need the heads rebuilt and clutch replaced, depending on wear. I had 155,000 miles, heads OK, replaced clutch. Follow the book, the conn-rod and head bolts cannot be reused. They are "Torque-to-spec". A full gasket kit and your done; about $500-800 in parts and machining. Just a bit of elbow grease and you save almost $2,000. Just to ease the pain; this engine comes out pretty easy, better than with older trucks.

Don't forget to put in a mechanical/electric progressive oil pressure gauge and sender kit! The original is just a fancy looking "idiot light", that's why it bounces!

If any one wants more info, just ask...

Good luck!

sorry to bump a old thread, but I'm also having the same problem as stated by others. wondering if there is any other way to fix this other than removing the oil pan? it looks like a lot of work to just pull the pan.

Is it the V6 or V8?

Hi Guys, I'm the newbie as I just bought my 99 F150 4.6 4x4 about 5 days ago. Coincidently, this problem JUST started 2 days ago. I will not buy any lottery tickets this week. But Mark, this is some great advice. I know for FACT that the oil was changed every 3k for the last 100k or so and this light/dummy gauge has NEVER came on. Now it has. So, with that said, do you feel that the carbon build up could be an issue? I want to test if the pick up screen is clogged, and I was thinking blowing pressurized air into the oil filter intake? Not sure if it would work or not, or if there is a better way. I never heard the engine tick yet, (even letting it run for 15 sec or so with the light on) and I tend to power brake it slightly at red lights and that tends to get rid of the lamp.. I already did the pressure switch and the actual gauges are on order from Summit racing. Should I attempt to douche the engine with the light oil and flush mix first? I'm not really familiar with the truck so I can't really say if it is losing any power or not, but it seems like I have to put my foot in it to get it down the freeway @ 70mph. Your advice would be much greatly apprieciated. If I have to dump a 460 in it I will, my wife may not like it but thats ok, lol. Thanks in advance for the advice!

Sorry, forgot to mention the truck has about 140k on it

My truck does the same thing every now and then but with the fuel gauge

The oils today have additives that eliminate much of the sludge that would accumulate in engines back 40 years ago. Back then, I knew guys that would fill their crank case full of fuel oil and run the engine for about a half an hour and then drain it and refill it with regular oil. They seem to get a lot of crud out of their engine but I am sure it also did some damage and I would not recommend it today. A really good mechanic that I used to work for told me to remove sludge you should do an oil change and put in good high quality oil. Then drive around and change the oil after one week. This sure sounds a lot safer than using fuel oil but I don't know if anyone has ever tested this by tearing down an engine to see how well it works. You could also add a engine flush products to your oil that are made by folks like BG at the link below.

http://www.bgprod.com/products/products.html

If I had the problem of sludge, it think I would try the one week oil change and add a engine flush product. Then I would try another one week oil change as see if it resulted in even more gunk being drained after driving around for a week. It would be inexpensive and low risk to experiment with this approach and a lot easier than tearing apart the engine

If this is a sludge/carbon issue, I may try to go a little aggressive at first and try the flush first. I don't want to do anymore damage to it by continuing to drive it. I'm still slightly power braking it (about 1k rpm) and that seems to be doing the trick on the light, I just don't know what kind of pressure I'm getting driving it down the freeway, I am being gentle with it though. I'm going to look into a flush tonight so thanx for the link, any other advice from anyone would be helpful too. I don't really want to slam a block in a truck that I've only owned a week.. Lucky me! Lol

A motor oil TV commercial many years ago showed how good motor oil cleaned by having a mechanic with very dirty hands pour fresh motor oil on his hands and rub them around to clean them. His hands were as clean as if he used a hand cleaner. I tried it myself and it works but I wouldn't do it today because the chemicals cause cancer.

Good thought, thank you!

What engine do you have? How many miles on it?

If you just have standard gunk from not changing oil often enough, then that may work. If you have clean oil and no sign of coolant on the dip stick, then it maybe worse than you think. The 4.2 '97-'03 V6 has a problem with the intake manifold leaking coolant into the oil. It mixes and turns the oil onto the worst sludge I have seen! It can't be flushed out, it has to be brushed out with solvent.

Unfortunately the 2WD F150 of those years has the cross member right under the pan, so you have to raise the motor, pull the pan and pick-up tube. This gunk was so bad I couldn't get it out of the screen, even with brake cleaner. Replace the whole tube!

As for fixing the manifold leak, you have to pull it and replace the gaskets! Now here is where the problem started. The gaskets are 1/8" plastic with a small rubber washer fixed to the plastic. Best I can figure is the rubber washer that seals the intake ports and coolant holes are too thin to seal tight. With the thick, hard plastic gasket, you can't torque it any more. I added a layer of silicone on both sides and it seals! It's a bitch to mess with, but removing the upper and lower manifolds is not that hard.

To remove the pan, remove the drive shaft and rear tranny mount. Unbolt the motor from the mounts and raise the engine about 6-12". Without the manifolds on it will clear the firewall just enough to snake the pan off and replace the pick-up tube.

Don't waste your time on different oils or coolant, it still coagulates and clogs the screen.

I know this sounds terrible, but it is what it is! I had to do mine twice! Replacing the gaskets alone, will NOT fix the problem. The second time mine did that, I pulled the motor and rebuilt it. It was very clear that this is the problem during the rebuild!!!

Mine had 160k miles when it clogged the first time! If you have seen the original post I put in, there are pix of the tear-down and the infamous gunk from hell!

Not that I know of!
 

Unless you have a 4x4, there is nothing that I know of! Wish someone would find a solvent that would clean the gunk and not damage rubber parts etc.

Good luck!

Thumbs down
 

Well, that didn't work. I have a very faint but evident knock... I flushed the motor and I got no sludge. I'm assuming the engine was pretty much sludge free. I drove it about 10 miles after the flush and as I was coming down my street, noticed a slight but evident knock. No tick, knock. I have not started it since. So the question is, should (or can) I slam bearings in this and make it good again? Or is it fate that I should O/H the engine, or replace it? I have it sitting in the garage ready to go. This guy needs help! (and a beer!) Let me know. Thank you in advance....:help:

I suspect that you have a rod bearing that is causing the knock and if that is the case, I would say your engine is a goner. Once it starts knocking it is scaring up the crank bearing surface. Installing a new bearing on this surface will just cause the new bearing to wear and start knocking again. Eventually you will throw the rod and further damage the engine.

My choice in this situation would be to find a known used engine from a salvage yard. Rebuilding an engine today requires a lot of know how and tools and not a job for most mechanics. Of course, this is only my opinion. If you do attempt it you can count on spending a lot of money on parts. For me at least, I wouldn't want to spend that kinda money and face the risk of making a mistake during the rebuild that would trash out the engine.

Sorry, I don't log on here very much.

But I just saw your post Kapis, and yes flush does NOT work... I said screw it, if the car was like this when I bought it, then the bearing clearances are probably messed up anyway.

So I tried a gallon of straight kerosene into to engine oil. Let it idle for 10 mins drained it out, but didn't see a lot of dirt or clunky pieces. No metal flakes etc.

Filled it back up with some 5w-30 supertech and a ford filter. Let it idle for 10 mins seemed fine. Drove it down the street a few times and it started losing oil pressure again.

I already replaced the LOWER intake manifold gasket. It was completely ripped on both sides. I'm assuming that the pick up tube is clogged like yours Frank_ford. As soon as I get some time after school ends. I'm going to drop the oil pan and see if it is a clogged pickup or not.

If not a clogged pickup, I assume the bearing clearance somewhere in the engine is bad and I'm just going to give up on it, but I don't hear any "knocking" from the engine. Just tapping on the passenger side head from the lifters, but that's suppose to be "normal" when it doesn't get enough oil.

Also I have not installed a "aftermarket" gauge in the truck yet, so I can't tell what PSI I am at. I will do that ASAP. I'll keep everyone posted.

http://i1149.photobucket.com/albums/...ps55763254.jpg

Well, it JUST started knocking and it is really faint. I can barely hear it with the windows down. And it was for about 30 seconds. So how long do you think bearings would last in it? If we're talking months or years I'll do it in a second. I would like to get more prepared before dumping an engine in it. If I have to do that I'll probably give it an upgrade (PI, 5.4, something with more balls, etc). I love the truck and really want to keep it...any advise?

If it is knocking and is a result of a bad bearing, you do not have much time left. You will most likely throw a rod the next time you drive it. It may be something else although I can't think what is could be besides a piston rod bearing. If you drive it around for a few days and nothing happens, I would get a second opinion by taking it to someone who knows something about Ford engines. Everything in that picture looks really clean and I cannot think that one flush got it this clean.

Just a point of information, in theory, if everything is working properly in your engine, there is never a metal to metal contact in your bearings. They always ride on a thin layer of oil. However, with dirty oil, hard driving, and cold starts, metal to metal contact is made and your bearings wear.

Don't give up on those fox bearings yet!
 

I agree with what your saying, but crank journals don't damage that easy. Most new rod and crank bearings are hard aluminum, or copper coated with Babbitt. If the rod and crank journals lack sufficient oil, the bearing will wear enough to create the soft knock, but the crank is very hard Nodular Iron, hardened and polished. If you pull a main cap (the front one gets the most wear) and you see copper, and the bearing is still in one piece, you can replace them. The bearing is the softest metal so it will take the damage, not the crank or rod journals. Once you get the pan off, replace all the bearings with oversize (if needed) ones. As long as you fix the coolant from mixing with the oil, you can replace the pick- up tube at the same time. This is a quick fix but it is still a difficult job. The rod bolts have to be replaced, as they are the new "Torque-to-fit" type, and require a lot of torque to set them, hard to do working under the truck, but it can be done!
Also when you replace the lower intake gaskets, apply a thin layer of RTV to keep them from leaking again.
Also, this thread pertains to the 4.2V6, not the V8s! I am not sure it is an issue for them.
Good luck!

Had the same knocking issue with low oil pressure at stop lights. Pulled the motor and oil pan was clean thank god. Found out my rod and main bearings were slightly worn down. No scaring though. So I replaced them all. Takes a lot of time but cheaper than a shop.

have any pictures of your bearings and crank journals? pics of crank etc?

Id drop the oil pan and check to make sure the pump isnt clogged.

Attachment 228655

Unfortunately this was the only one I took of a main bearing. Didn't take any of the crank but is was virtually new looking.

This is for the 4.2V6.

You can try, but this sludge is different since it is coolant that is solidifying the oil, not just old trapped oil & carbon from being old or not changing the oil enough, etc. I had to throw away the pick up tube because i couldnt even clean the screen with a wire brush and brake cleaner! I tried Acetone, and about 4 other solvents and it didn't even make this sludge from hell softer!!!

That bearing looks good actually, just lots of miles! The wear is so smooth, its not from lack of oil, but carbon in the oil. Changing oil more often will help. I would slap a set of new aluminum bearings in and change the pick-up tube. Check for any slop in the rod bearings while your there. You can't really change them from under the truck, so out comes the motor if you feel any slap. The rod bearings are a bitch! They require stretch-to-torque bolts. Has to be done on a stand.

The pump is not in the crankcase, it's bolted onto the timing chain cover, lower front of the engine. It's never the pump though, tough pump. Oil can't get to the pump if the screen is clogged on the PU tube.

Mark, did the lower intake gasket and picjk up tube fix your problem? My drained oil has bubbles on top of it.. im assumin is the coolant.

Update: I did pull the motor. Its a 97 4.2 by the way. Replaced lower intake gasket, front and rear main seals, oil pan gasket, and rod and main bearings. All old gaskets and seals were leaking. This was a serious project. By far the biggest I'd ever done. Took me 5 days, after work of course. Fired it up yesterday and no more low oil pressure. The motor ran better to like it had a little more pep. Mabey the new bearings lets it feel young again like it doesn't have 135,000 miles on it. Anyhow well worth the time.

Did you check clearances at all? or did you just put new bearings in and that was it?

Nope just threw in new bearings and slapped her back together.

Sweetness! I'm getting ready to do oil pan gasket and timing chain cover gasket on my 08 4.2 :/

If the crank journals are not scratched, and we know the block won't change, then a stock thickness bearings will work. But if the crank journal is scratched, or marred . You should plasti-gage the bering fit to check for too much removal of crank material. It's easy, I got a kit with my new mains. If the crank is too far out, you'll have to pull the engine and have the crank ground or polished depending on how much material is gone, and put oversize bearings in. I wouldn't worry if the bearings look as good as the pic above. Just DON'T try and remove the rod bearings unless you are willing to pull the engine. You can't install Stretch-to-torque bolts from under the truck. Motor has to be removed!

While your there check the timing chain for stretch. You may need a new set of gears and chain. Also the Bering for the counter balance shaft.

UPDATE!
Still getting low oil pressure at stop lights in drive. In park the pressure bounces back. My next change will be my oil pump. I really need to put a real oil gauge in but I haven't yet.

Did you replace the pick-up tube? You can pull the oil pump and check clearances between the gears and between the housing and gears. These are usually not the problem, they are bullet proof. They pop-off the timing chain cover, easy to check.

No the pick up tube was clean. The screen at the bottom had a couple small pieces of gasket in it but nothing stuck in it. I moved those out. As far as the clearance I didn't check and wasn't aware of this being a rare issue. Mabey I need to just replace the oil pump?

I think you need to change that oil "idiot" gauge for a good electronic first. You can tell so much more of what is happening.

If you pop the cover off the oil pump, you can use a feeler gauge to check the clearance between the gears and the gears between the housing. I think the only way to damage this thing is if the truck overheated, or ran dry on oil? The tolerances are in the repair manuals, like Clymer etc.

I got the truck with 100,000 miles on it so uncertain if it was ran low on oil or overheated before me. Ill put a better gauge on next then before changing the pump. Do you know what psi it should be running at idle?

Well I changed the oil pump with a new one and still have low pressure. Also I stalled a manual oil gauge. Driving its fine around 35 psi. But after its warm in drive stopped its at 8psi. I'm not sure what else it could be now. New bearings,oil pump, gaskets, ect. Any ideas anyone?

Well Matt, here is the little I know about these engines. Sludge is your enemy, if you have sludge, this will cause this problem, especially in the pick up tube screen. The oil pumps are a brick **** house and are rarely if ever the problem. I am now to the point of replacing the rod bearings in mine. Good news is that you don't even have to pull the engine, bad news is that it's about twice as difficult as it sounds while standing on your head. Typically it is the rear bearings that will wear out first because they are the last to receive oil. My truck was doing the identical thing, pressure and all, that yours is doing. Do not drive it as you may unload one of the bearings and your engine will be knocking on heavens door. Bearings are $80 ish from ford and you could likely knock it out in a weekend with the right amount of motivation, tools, and beer. Best of luck to you my friend, if I can be of any help let me know..

Try to run lucas oil stableizer.. I am running 2 quartz of it and the rest 10-30 oil in it.. I don't have hardly any problems when I do this... I have replace my pick up tube oil pump lower intake gaskets and much more.. and this is the best solution I found so far.. good luck and if you find the problem let me know..

One thing though, these are "Stretch-To-Torque" rod bolts. You torque them to a high tourque, then tighten them 1.5 turns past. It takes a mother or a torque wrench to get that stretch. May be difficult doing this with the engine still in the truck? The mains are not this way, standard torque.

Attachment 262662

This is what I found under my vavlve covers this weekend. I decided to do this because when I start my truck now white smoke comes out for only a minute then clears up. So I decided to replace my valve seals and this is what I found. GUNK! The drivers side wasnt as bad but definitely had traces of harder build up. Mabey this was causing the low pressure.

Wow that's a nasty suprise ^^

Here's a few proper working idiot gauges at start, -

A 01 5.4L 54,000 miles, -

https://plus.google.com/photos/10028...93822927083789

A 98 5.4L 309,000 miles, -

https://plus.google.com/photos/10028...93822927083789

Turns out I still get a little low on oil pressure. Ive done all I can im throwing in the towel and just gonna run it till she wont run know more. Who knows I might get another 150 thousand out of it.

Matt put a mechanical oil pressure gauge on your truck. Mine was bouncing too and oil light would come on in gear at red light. Replaced my sender and added a tee for mechanical gauge. No more bouncing and great pressure.

I did awhile back. It still reads low in gear while warm.

Just wanted to say thank you for saving my truck I bought it used and whoever had it before me didn't treat it right so I am slowly trying to save it

The FILTER SCREEN inside the oil pan is surely restricting oil flow going to the pump. :thumbsup:

Right. -That'll do it in, if let go. That's the pic-up tube and screen btw. Or oil sump.

Not to worry... Yet!
 

The oil pressure gauge and sensors, are actually idiot lights! Once the pressure gets down to 10-12psi, the gauge just switches to show no oil pressure. Once you get above that pressure the gauge pops on like an idiot light. If you rev it up to 3,000RPM, the motor will be producing 60psi or so, but the gauge will only show medium.
Add a good electric-variable oil pressure gauge and you'll see.
If you have the 4.2 V6, it has a bad habit of leaking coolant into the oil, and slugging up the engine. Once the motor gets enough of this slug built up it can clog your oil pick up screen. This is why the oil pressured is eratic. You can give the engine a good flush, but the coagulated oil will stay in the super fine screen. Eventually you'll start getting lifter pump down from clogged lifters and it will start ticking. Then you have to replace the lower intake manifold gasket with new Felpro aluminum gasket, DO NOT USE The plastic Victor Rienz (Sp?)! THEY WILL LEAK AGAIN.
You'll also have to raise the engine, or pull it to get the pan off and replace the screen.
Scan below and you'll see lots of guys with this same problem, it's common on the 4.2V6. If you have a V8... Never mind. 8-)

sorry, haven't gotten on here much.

But I think your problem is the clearance in the crank and bearings. That bearing that you pulled looks VERY worn to me. Even or not, it was pretty worn. It would have been better to have token the crank to a machine shop and see if they were still within spec before placing new bearings in.

New bearings should look silver no copper showing. The copper is under the silver coating. When it digs into the copper it means it was lacking oil at some point. for how long who really knows. Even with that little bit of no oil. It could have rubbed your crank every so slightly where you won't be able to tell with the eye. Only with professional machinist tools could you tell. That or plasti gauge the bearings before reinstalling everything.

What oil are you running now in the engine?

Try maybe running heavier weight oil. Maybe some Shell Rotella t6. See if that does anything to the oil pressure. It raised mine in my honda SLIGHTLY at idle.

Also heard you should run motocraft oil filters only... never a fram... There a TSB about it somewhere.

Location
 

Location of the unit