Any Ford 4.6 Experts on board?

Bought a 2002 Exploder 4.6l for a 4 x4 go to work car as my place of employment doesn't recognize level 3 snow emergencies. We have had a couple in the past and she currently has an 03 and they are nice driving trucks.

Anyways, I was randomly getting the oil press light at warm idle. Checked with a real gauge and starts out at 60 cold. Within a couple minutes down to 40 and after a run around the block about 7ish at idle. 140k on engine.

I pulled the pan thinking the oil pickup might be plugged or maybe the pressure relief on the oil pump stuck open, but struck out on both counts.

I did find some metal in the bottom of the pan. It sticks to a magnet so its not bearing material. I believe it has had some timing chain work in the past so possibly remnants from that?

Engine sounds good and the one time I changed the oil it didn't rattle any worse or sound any different on the dry start than the other one we have. I find it hard to believe main and/or rod bearing could be that bad.

I guess my question is....Is there anyplace else this thing can be dumping oil?

Oil pump would require pulling front of engine and all the timing chains. Main bearings look doable from below but a real nightmare. Rod bearing wouldn't be too bad. I haven't pulled any caps yet as they appear to all be torque to yield bolts and was hoping there might be a simple fix.

Most of what I've read on line says these don't really have issues like this...

Thanks for any help you might have, Jeff

If you still have the pan off, pull some main and rod caps, see what's in there. I have reused torque to yield bolts and had no problems.

If all looks good my next choice would be an oil pump. May or may not make a difference.

There are lots of places an engine can loose oil pressure. Be interesting to know how long this has been happening, but probably no way to find out.

with the oil pan off, pressurize the oiling system and see what piddles the most oil.

Platigauge the mains and rod ends.. Usually there or the oil pump is weak. If wear but acceptable range, roll in new bearings. Usually one main cant be changed, due to pressure on the thrust bearing main. Oil pressure will come back up. Lots of times you can get .003 over mains for worn engines.. oversized just a bit to tighten up the engine, but not enough to have to turn the crank. However next step will be oil pump due to volume.

Our family has quite a few 5.4's. The same except stroke. Have never had any oil pressure issues. Or timing chain. Just spark plugs. Daughters Expedition has almost 300000. I would put 15x40 oil in it. And some Lucas additive.

I do not know if this is at all helpful, but my Dodge sending units go out all the time. They are ok warm and when new but eventually go bad. I have taken to wrapping the new one in latex to keep dirt/oil out and that helps. Once it starts going bad I pull the plug and clean and apply contact cleaner which gets a few more months out of a sender.

You sure are brave. Torque to yield bolts are designed to be stretched to the yield point one time. A second stretch would over stress a bolt to the point of causing failure in a short time. Replacement bolts are a lot less expensive than doing a head gasket over again - or worse throwing a rod through the side of the block over a $2.00 bolt. After a lifetime of working on engines and transmissions added to an abundance of factory training, I am inclined to take things on the safe side. Better than losing a $5000 engine to a $30 set of bolts.

Many years ago I had this same problem on a Ford pickup. Was in fact worn bearings. Replaced them and truck ran like new. If you didn't buy it new you may not know the oil change, etc history of it.

Jim, I'm sure you are right, just basing it on low budget projects and delusional thinking...

I did some experiments with the yield to torque head bolts, new ones. Seems like the turning procedure matched up with the torque specs for that size bolt.

Also got to thinking, when the factory tightens down a head, they use a multi spindle machine to pull all the bolts down at once, easy to have an encoder that counts the turns, all bolts load equal, gasket compresses equal, perfect world! Same thing with a set of mains, rods, etc, all pull equal at the same time, but take away the gasket compression.

But then when I reassemble something, I'm doing one bolt at a time, which means I have to run the torque sequence several times to compress the gasket, preferably run it again hot. I just can't see the yield to torque method being an advantage over the torque wrench under those conditions.

As for not reusing critical bolts, that's been around for ever, long before yield to torque bolts were thought of. But never had a problem. If it doesn't feel right torquing it down, something's wrong, check it out. But if it will torque, I call it good!

Yep, I'm old and hard headed! Not doubting the technology, just the way I see it! LOL

Those are zero tolerance engines , Ford always told us to never use plasticguage on these engines or you could break the rod or main cap. They are not like the old 302s , to get bearings you match a number on the block and crank . I rarely had oil pressure issues with a 2 valve modular , I would look at the camshafts for scoring as an area oil pressure could be lost. Most common spot for oil pressure loss was timing chain tensioner seal leak between tensioner and block.

I agree.. they are designed for one time use. vw has tty bolts on the engine mount, and when you change the timing belt, and use the old bolts... they work loose and then snap off....................................... the engine casting for the mount... only cost you a new block because your too cheap to follow instructions. The the labor is horrendous.... There are MANY one time use bolts out there now the where the service manual say REPLACE ONLY WITH NEW BOLTS... there is a reason.

(quoted from post at 18:40:33 12/11/15) Those are zero tolerance engines , Ford always told us to never use plasticguage on these engines or you could break the rod or main cap. They are not like the old 302s , to get bearings you match a number on the block and crank . I rarely had oil pressure issues with a 2 valve modular , I would look at the camshafts for scoring as an area oil pressure could be lost. Most common spot for oil pressure loss was timing chain tensioner seal leak between tensioner and block.

Click to expand...

great,, but what to you do on a USED engine as said with over a hundred and forty thousand miles on it.... yes not on a new, but used?? your saying you have to pull the crank and mic it and the caps everytime?? If it were zero tolerence, it would have oil pressure....

Timing chain tensioner leaking between block and tensioner is a good possibility . Scored camshafts can loose pressure . The pump may be worn for some reason . Those usually put out very good pressure . Do Not put 15-40 or any heavy oil in it , if it can't make pressure with 5w20 it has a problem . Check a rod and main towards the rear , cyl 7 or 8 rod and see if they look scored or scratched from debris . I would not use plasticguage as we were always told not to use it on these engines because clearance was so close it could crack a rod cap . The rods are compressed metal powder design and will break if not handled properly. It should be obvious when you look at the rod bearing if it is good or bad. I have had a couple that had rod knock from an obviously shot scored bearing but they still had good oil pressure. Unless the past owner really abused it those engines almost never have problems.

Thanks for all the ideas. Didn't have much time today to mess with it. I did sort of take Bob's advice....still had my hose whip for my oil pressure gauge hooked up so I put about 40 psi of air into the oil system.

Didn't see a whole lot of bubbling or hissing on the bottom end, but I can definitely hear it coming from up top somewhere.

RobgIN, you mention a seal on the tensioners. I have the old junk 4.6 out of our other explorer that I've been taking apart to get an idea how this one works. There were no seals under the tensioners. Just metal to metal. That motor was a ford factory rebuild. Should it have a gasket of some sort?

I think my next step is to pull a valve cover or 2 and see if i can find my "air leak" up there. Maybe I can see down far enough to get a peek at the tensioners.

If anyone has anything else, feel free to chime in.

Thanks again.

Several ways to check oil pump that I would think will work on most modern engines.

1) Oil gauged installed ignition disabled crank the engine you should see OP as soon as the engine starts to crank over of at least 15PSI are more...

Yes) you do not have a oil pump issue
No) move to 2)



2) Vacuum gauge attached to oil pick up ignition disabled crank engine over you should see at least 15" of vacuum as soon as the engine starts to crank over.

Yes) You do not have a oil pump issue
NO) you have a oil pumps issue are a pick up issue.

1&2 yes and you have low OP hot Pressurize the system as Bob posted DO NOT BLOW STRAIGHT AIR look for a large leak are the area it may be coming from.

Never assume by looking at just a few crank are rod bearings the rest are good. It only takes 1/2 of a journal set to fudge up the pressure... I have got my butt kicked by being lazy REMOVE THEM ALL. I have not been deep into a 4.6 other issues that may affect OP I am not aware of... I have seen low OP on these the timing chains slapped and rattled till they broke... Folks have drove up with this issue and had the timing chains and associated parts replaced I passed on any attempts to repair I have enough headaches don't need anymore...

15/40 will blow the rockers arms off on cold start up.

The advantage to torque to yield bolts is that once they have been correctly tightened and yielded, they will more closely follow the expansion and contraction cycles that an engine will see. It is a given that aluminum and cast steel have different coefficients of expansion. For that reason, aluminum heads on a cast steel or cast iron engine block have always been a problem.

Going back in time, in the 1970s, I was working in a Buick dealership. We had several models that had aluminum heads. The 1964 Special had a 300cid V-8 with aluminum heads. That engine needed the head gaskets replaced about every 30k miles. They used some fancy flange bolts with special washers for head bolts. Still ate up head gaskets.

Later, in the 1980 era, I was working in a Ford dealership when we first saw the stretch bolts in Escort engines. Then around the introduction of the 1.9 engine, head gasket problems reappeared. The factory reps selected several cars with gasket failures, and sent out brand new complete engines to replace them with. They took the failed engines back to Dearborn, and analyzed the failures. That was a big step in head gasket technology.

The gist of the whole thing is that modern engine have much better head gasket life with the torque to yield bolts. The factory engineers tell us not to re-use the bolts. They are much smarter and better educated than I am, so I follow their advice. If you want to take your chances with used stretch bolts, that is your choice. However, I do disagree with recommending it to other less experienced and less knowledgeable folks. That way, when a failure occurs, it will not be because I told somebody to take a shortcut or to "cheap out" on doing it properly.

I do enjoy working on cars up to a point, but I do not want to keep doing the same job on the same car over again for a couple of reasons - time consuming would be one reason and cost would be a second.

Take a plastic 6 pack retainer. Using one finger on each hand, pull one ring apart. AS you pull the Poly will stretch moderately easy for a given distance. (yield) after that distance the force goes up, but the plastic does not stretch, then it breaks. The used bolts are pre-stretched, and are not going to yield nearly as much before fracturing. Nothing is as simple as it seams. Jim

the older ones were metal with an o ring type seal then went to a plastic type that just used a very small bead of sealer around it when you look at it you will see the sealer pushed out or missing. Those tensioners are to be replaced if removed due to the sealer bead being a one time use item. If you are hearing a lot of hissing up top I would be looking at all cam journals . The oil leak at tensioners starves cams for oil and the damage begins there.

There is another post on here where the poster is asking about what oil to use in his Ford. Ford says 5W-20, he thinks that's to thin, this is what happens when you use the thicker stuff, oil didn't get where it should of been because it was too thick, no oil allowed more wear, now oil can get there but won't stay around long enough to lubricate.