I am an IT consulting professional by trade with some modest automotive repair and tooling experience.
I have a 99 Exp XLT 5.4L 2WD unit that has (I think I have narrowed it down) a failing/failed/clogged oil pump (after much observation and forum research).
The truck has 170,000+ miles and started to have the oil pressure guage drop off and warning light coming on and off abruptly when the oil level got below a certain point. I would add a quart of oil or so (back to "full") and the behavior would go away. The engine burns oil but there is no visible tell-tale smoke in the exhaust and no visible leaks under the vehicle where it is parked at night. I had always attributed this to just the "normal" behavior for this engine as it has aged.
Then, recently, the oil guage fell off abruptly and the oil light came on and a VERY perceived knocking in the lifters (I assume) would simultaneously become evident. The engine has long had a slight knock, but, never had a loss of power and I assumed 87 octane and just aging. But this new behavior was abrupt. I added oil and verified the level and that was good. Now, when I start the engine, it starts up normal and idles fine, but, shortly thereafter (with the oil level good), the oil light comes on, the guage falls and the knocking commences. I have not been driving it except gradually up and down the driveway to observe the behavior.
after MUCH reading, and all things considered, it appears that the oil pump could indeed be suspect. what makes me further think this is that there are moments that the oil light will go off and the guage returns to its nominal position and the knocking abruptly stops and again idles fine. It seems to manifest the problem more as I begin to apply the gas and rev the engine up. It will often start to rev up normally and then the light comes on and knocking commences.
So, am I on track with this??? The truck has been parked in the driveway ever since as we have a 3rd car. I am now getting around to trying to get this looked at. But, I assume I will have to have it towed if I take it to a shop. So, I am trying to do some homework.
Is this a costly repair??? What else might it be? If the pump pick up line is clogged and the pump itself it OK, how to test and likewise, is there anything I might do to correct that situation? Is this something I could do myself or will the engine, tranny, whatever, have to be pulled out and apart to even get to where the pump can be examined?? I have read that you have to remove the timing chain and the oil pan to get at it. And, with a 9 year old, 170000+ mile vehicle, is this even worth bothering with fixing or should I "scrap" it (Kelly BB indicates about $1500 for this)?
Any input would be greatly appreciated. I know throwing enough $$$ at it will fix it, but, with gas $ and the economy the way it is, I simply need to be smarter about spending $ in general these days.
Run engine flush through it and then do an oil and filter change. If the problem goes away it was a bad filter. If the problem gets slightly better then you have sludge on the bottom of your oil pan that is restricting flow to the pickup tube. At this point I would only give the oil pump about a 10% chance of being the problem.
No please dont use any additives or treatments, they are all gimmicks. The best thing for your motor is straight oil. First off you should do an oil change and measure how much oil comes out of the motor. Second you should get a Motorcraft oil filter. Not being a Ford head here, but Motorcraft is the best filter you can get and keep it OEM. Read here to choose a filter, Engine Oil Filter Study
After youve done all the above, of course adding the right amount of oil your truck takes, drive it more often. Check out the oil pressure sending unit as well. If theres no tell tale signs of oil leaking or burning, then its probably a bored motor that needs to be entertained.
__________________ Big Dave 99 Expedition 5.4 4x4 Southern California FTE
When you say "engine flush", I assume you mean an oil treatment/additive? is there are particular brand you recommend??
No I don't mean an additive. Just go into an auto parts store and get engine flush. I brand I've used is made by "Gunk". This is a cleaner that will dissolve some of the sludge and give you an idea if that is the problem or not.
No I don't mean an additive. Just go into an auto parts store and get engine flush. I brand I've used is made by "Gunk". This is a cleaner that will dissolve some of the sludge and give you an idea if that is the problem or not.
Gunk or Seafoam will do it. Add the stuff to the oil and run the engine until it reaches normal operating temperature. Keep an eye on the oil gauge, if it starts to act up, cut the engine immediately. Replace the filter with Motorcraft as stated previously. Let us know the results.
