Engine Cooling problem
2000 Ford F150 V8 Four Wheel Drive Automatic

Until recently I have noticed a rather big problem. I've had my 2000 4x4 f-150 for about a year and a half. I useually change my oil @ 6 month intervals. Last oil change I went w/ RP. Great stuff better milage and increase in proficiancy. As of now I am a tad over due a little late in to my 6 mon interval. As I drove off to work the other night I could hear a tapping noise coming from engine... low oil ... of course! So I attempted to "band-aid" the situation and did so a quart at a time. after 3 quarts barely a tickle on the dip stick, THERE WAS NOTHING THERE... so no leakage, none. Where has my oil gone, whats burning it up in 6 months fast enough where at these intervals theres no reserve?

As strange as it may sound, I have seen that some oils burn and some dont. I have had situations where a customer switched to synthentic and began having oil consumption problems or gone from std to syn and had the same issue.I dont really know why. did you ever have this problem before? how many miles are we talking at 6 mo intervals?

maybe 5,000 + not to sure on specifics.

and just to add there was never a change from std to syn, truck has been on syn all its engine life.

I was told that the lifters could be the culprit but then again im not sure.

you stated that you changed to rp (royal purple?) now it uses oil? What I was getting at is did you have an oil consumption problem before the change to rp? Not exactly sure how lifters make an engine use oil.

the lifters may not be the problem of the oil consumption, but he's pretty sure its whats causing all the tapping. And no prior to RP there was no harsh oil consumption.

Theyll do that when they are run out of oil.I would go back to original brand of oil and see if the consumption problem goes away

As a matter of fact, I just did a complete oil change back to the previous oil filter and oil, there was mo change however, tapping did not go away. A day later however I added Lucas stabalizer and the problem has become intermitant, meaning tapping goes away and comes back but at a lower volume.

Are we talking about a fast tap or a low speed knock? The lifters may have been damaged when it was run out of oil. Does it have good oil pressure? The seals in thelifters may have been damaged with lack of lube and that is why they will pump up sometimes, but wont consistently hold pressure

First of all the knocking sound is in tune to the idle of the engine and its rev. Second the oil pressure seems to have somewhat stabalized to what used to be its norm, and they do hold pressure. but just as the knocking sound the "tac" on the oil pressure gauge is in tune aswell

Ok, is the noise a slower deep knocking noise or is it a fast tick? This is the difference between a bottom end noise and a lifter type tick.If the oil gauge fluctuates with the noise, you may have bearing damage in the bottom end (crank,rods).