I've been having to add a quart of oil between every 3,000 mile oil change. This is a used 2000 2.5L motor now with about 150,000 miles on it and 317,000 on my truck. I notice the oil is coming from somewhere on the side maybe in a few places. I think the oil plug is dripping a little. I'm going to try an OEM Ford plug because I've changed them several times with aftermarket plugs and they never seal right. I thought it might be the oil pan gasket but it doesn't really look wet around the flange all the way around. Then I checked higher up thinking it maybe the valve cover gasket which has been replaced and it's drive around the cover. I noticed under the power steering pump bracket it's all wet with oil. It's not the power steering, I've never had to add to it. It appears to be in the middle under the intake. I didn't see anything from the pressure switch. It looks like it's mostly around the pcv valve box. Is there a gasket that leaks there? Or anywhere else that is common to leak? I fixed my transmission pan gasket leak which cleared up some of the mess on the bottom. How hard is it to change that pcv valve box? They call it a crankcase vapor separator where the pcv valve goes.

 

The rubber PCV valve elbow is known to crack underneath & leak vacuum & with the mileage you have on this engine, if it has a good bit of blow by & or your using a lighter/lower viscosity oil, the PCV valve could be clogged up, worn, or it could be dripping an oil mist collection from a cracked elbow. Maybe have a close look at the elbow & change out the PCV valve & see how things go.

If excessive bow-by seems to be a problem thats over pressurizing the crankcase, maybe consider a 5W-30 oil viscosity in a high mileage recipe. It'll have more detergents to tidy up deposits in the piston ring lands to free up the rings for a better seal & the higher viscosity can also help worn rings make a little better seal & maybe help blow-by & compression some. It'll also have extra seal softening/swell agents, that can help with shrunken/hardened seals. Some thoughts for pondering, let us know what you find & how it goes.

 

I couldn't really tell if the crankcase vapor separator itself was leaking from the gasket. It appeared to be more wet on the top of the can where the pcv valve pushes in. This one doesn't have a rubber elbow. It's a long rubber hose that goes to the intake and the pcv valve sits in a metal can called the crankcase vapor separtor under the front of the manifold. When I did the plugs and wires and the upper intake off I replaced the pcv valve with a metal aftermarket replacement one. Is it better to use a Motorcraft one eventhough it's plastic? If the gasket that mounts the crankcase vapor separator is in fact leaking it is not able to be found anywhere. Ford can't get it anymore and I haven't been able to find it on a parts locator or ebay. In fact I can't even get the crankcase vapor separator to come up in a search at all on EBAY. So I may replace the pcv valve, it's not clogged but I'll try a Motorcraft one. As for the oil I usually use whatever is on sale or the cheapest 5W-30 and I use 5 quarts filled to the max mark on the dipstick. I know actual total refill is 4.5. What about if I switch to the Motorcraft 5W-30? I know it's a high quality synthetic blend. What an engine supplement like Restore that is suppose to help clean up the cylinder walls? I bought a Ford oil plug which should stop some of the leaking and then I might be able to tell better if it's a gasket or the valve causing the oil leak. I do have a very random cylinder drop while driving that one time threw a P1131 code which has a probable cause of a restricted vapor recovery system or stuck open egr. I don't know if they are referring to the purge system or the crankcase vapor system. It only happens every once and awhile and the Check Engine Light went off and hasn't been back on. It might do it once a month or it could be a couple times a day. It says in the Ford tech book a problem with cylinder 1. I don't know could it be caused from a pcv problem?

 

Maybe consider doing a crank case blow by pressure check, to see if your ring seal is a problem. There is a blow by pressure spec for all engines. If blow by pressure is out of spec it can force leaks past the weakest seal/gasket.

With your scantool you could perform a cyl balance test to determine which cyl is suspect, then go to that cyl & perform a compression test to get an idea how much it may be contributing. There was a thread on crankcase pressure not too long ago, bet a search would turn it up.

If you don't have a scantool to do the cyl balance test, hook up your vacuum gauge & perform the blow by test with it, to get an idea what might be going on.

Or you coud cut right to the chase & perform a compression test on all cyls.

I'd also stop over filling the crankcase, as too much oil is not good, as if its high enough for the crank shaft to dip into it, it'll cause aeration of the oil, which isn't good from a lubrication stand point, but it can also cause excessive misting of the oil, all a vicious circle. If you live in hill country, it could exacerbate a crank case over fill as you drive over tilted ground & have the crank shaft strike the sump overfill.

More thoughts for pondering, let us know how it goes.

 

This one would be a pain to do a compression test on. The original 2.5 I had lasted 228,000 miles before it spun a bearing. It never overheated and never leaked oil and was treated to regular tune-ups, and oil changes every time it was scheduled. It had oil pressure problems probably due to bearing clearances as it got miles on it. It died on a vacation through the mountains of Tennessee and Kentucky finally dying in a parking lot in Kentucky it just went silent and everything shut off. I was disappointed that I only got that many miles out of it as our 1993 2.3 is still going with 300,000 or close to since I can't remember the mileage because it doesn't have the extra digit. But on this 2.5 it had 50,000 on it when we put it in and now has about 150,000. I know how to hook the vacuum gauge but wouldn't know what to be looking for. I definitely don't have a scan tool that can perform a balance test. It's $120 diagnosis fee at the local Ford shop which is a lot but I know they determine what's wrong with it rather than a shadetree who just guesses most of the time. If this one goes out before it's time I hope I can find the Ranger I always wanted a yellow Splash 4.0 auto. I believe the best looking truck Ford ever made. I just hope for the best that it's nothing major yet.

 

Here is a link to a vacuum gauge tutorial, scroll down & click on scenario #4. How to Use and Interpret a Vacuum Gauge

 

I would wash the oiled areas before trying to diagnose, unless there is an 'oil washed' area where the oil flows enough to keep the dirt and dust from collecting.
I think the vapor separator has an O-ring where it goes into the side of the block. Unless the thing has been whanged, it's unlikely to be leaking there.
You can check that the PCV is functional by removing the oil filler cap, and placing a piece of paper over the opening with the engine at idle. I'm pretty sure it should pull the paper down onto the top of the cam cover and develop a slight vacuum. If not, either the PCV is gummy, the hoses are leaky, or you have more blowby than you should.
I don't know the later models, but the older ones had the PCV valve 'in line' with the hose from the separator and the hose leading to the back side of the upper intake manifold. It was so in-line that many were unable to find it without directions. It had no elbow, but the hoses were pre-formed.
tom

 

Yeah I looked a little closer, where the gasket on the vapor separator should be it's dry there and against the block behind it. Somehow it's spraying all over the underside back of the power steering pump bracket and all over the separator case. I visually looked at the pcv valve and it looks ok. I haven't removed it yet. I replaced it at 300,000 when I changed plugs, wires, coils, fuel filter, and air filter. It's now got 317,000 on it. If it was the case the pcv valve was being unseated enough to cause some oil spitting all over the block. What's the likely cause of it? Sometimes it does come out of the grommet in top of the separator just a little.

 

A couple of things you could consider trying. Pinch off the air breather tube to the valve cover, remove the oil dipstick & attach your vacuum gauge to the dipstick tube, start the engine & you should have 1-3 lbs of crank case vacuum at idle. If not, you either have a leak in the PCV system, or excessive blow by & with the mileage on this engine, both belong on your suspect list.

To check the PCV system, you could try your own smoke test, by blowing smoke into the crankcase through the dipstick tube & look for smoke leaks around the PCV plumbing.

With your scantool, you could perform a cyl balance test to maybe get an idea if one cyl piston rings are more supect than the others, or perform a compression test, or a cyl blow down test if you have shop air available & listen for the blow by, via the hose attached to the dipstick tubing.

More trouble shooting thoughts for consideration, let us knowwhat you find.

 

At the back of the power steering pump on the block is where the oil pump drive shaft is set in the block and capped off with on cover and an oring. It used to be where the distributor was. I have seen them leak around that cap.

 

So I got a new motorcraft pcv valve but haven't put it in yet. I don't think there is an issue with the pcv system though. It may have been spitting out oil because it wasn't seated all the way in the grommet earlier but since I pushed the one in there now down it doesn't seem to be throwing any oil. But I'll see about that since I degreased the area real good and I'll check in a few days of driving. I also go a new OBD-II scanner today that records live data while you drive or it can. It didn't cost thousands of dollars but maybe it will give me some idea of why that P1131 code came on and why it randomly drops a cylinder and stumbles. What PIDs? do I need to look out for, I guess that's what they are when it records live data. It reads the following live data: DTC-CNT,FuelSys1,Load-PCT,ECT,SHRTF1,LONGFT1,RPM,VSS,SPARKADV,IAT,MAF,TP ,O2B1S1,SHRTFTB1S1,
O2B1S2,SHRTFTB1S2. Which ones do I need to watch out for causing this kind of problem?