Massive oil leak.

[SouthernLincoln]

I'm having a rather massive oil leak. I'm not quite sure where its coming from as there is no oil on the top of the engine...but i can clearly smell it burning on the downpipes on the exhaust. The only time the "leak" seems apparent is when i have to get on the gas. Any other time its hardly noticeble.

i'm thinking it might be the oil pan, or rear seal. I wouldn't think its the front as i just had that off and replaced it about 6 months ago. Also the valvecover gaskets have been replaced, along with a new pcv valve. I don't think its burning oil, as i don't see it smoking while i'm driving it.

Also, something odd i noticed a couple days ago when i had the upper intake off, doing the valvecovers, the PCV valve had no oil what so ever on it. Could the screen underneath the pcv be stopped up and causing the whole problem? I'm kind of confused here... :dunno:

[gadget73]

Clogged screen is very possible. Did you notice if it had oil coating the top of the transmission? A common place for for massive oil leaks onto the exhaust that isn't super easy to spot is the rear of the intake manifold. There is a cork seal that sits along the top edge of the engine block between the lower intake manifold and the block. The cork pushes out and oil blows out of the gap. Have a look down the back of the engine, if the top of the transmission looks all juicy and covered in goop, thats very possibly the issue. Changing the PCV screen may slow it down, but if it was totally clogged, its very possible thats what caused the seal to blow out.

[SouthernLincoln]

How would i go about cleaning the screen underneath? Carb cleaner...? I thought about the lower intake gaskets, but i didn't think the screen would cause that to blow out. Also i didn't notice an oil or goop on top of the trans while i had the upper off. Guess i've got to keep looking.

[OVERKILL]

How would i go about cleaning the screen underneath? Carb cleaner...? I thought about the lower intake gaskets, but i didn't think the screen would cause that to blow out. Also i didn't notice an oil or goop on top of the trans while i had the upper off. Guess i've got to keep looking.

Take a pair of needle-nosed pliers and pull the screen out. Soak it in carb cleaner or AC Delco combustion chamber cleaner, that stuff is INSANE, cleaned out my IAC so that it looked brand new!

Positive crankcase pressure can and often WILL blow out various seals in the engine, including, but not limited to, intake end seals, valve cover gaskets and around the oil pan, front main, rear main....etc. The rubber end seals found in the Explorer intake kit or even the newer Felpro kit for the stocker don't blow out, and, if you put something like the Ford grey RTV on the tops and bottom of them, they are pretty much glued in there permanently. That's the stuff I use, and it makes a sickeningly insane bond; great stuff!

Get a can of brake clean, start cleaning off any grease/residue on your engine, and oil pan to get it all as clean as possible. That will help show you where its leaking.

[SouthernLincoln]

What about the oil filter seal? My oil filter is covered in oil, and i think maybe thats where the leak is coming from. I just don't understand how it could have blown out unless i over-revved the engine.

Then again...its possible that it was just a bad filter.

[OVERKILL]

What about the oil filter seal? My oil filter is covered in oil, and i think maybe thats where the leak is coming from. I just don't understand how it could have blown out unless i over-revved the engine.

Then again...its possible that it was just a bad filter.

As I said, clean it all off with brake-clean and see if you can determine the source.

[lairdt]

What about the oil filter seal? My oil filter is covered in oil, and i think maybe thats where the leak is coming from. I just don't understand how it could have blown out unless i over-revved the engine.

Then again...its possible that it was just a bad filter.

Common mistake is to leave the previous oil filter gasket behind, and then eventually oil blows out between the two gaskets all over the place.

[87 town]

Common mistake is to leave the previous oil filter gasket behind, and then eventually oil blows out between the two gaskets all over the place.


yep, very possible that the old gasket remained or the new one just got loose. hope that was all it is. easiest fix there could be.

[gadget73]

Don't clean the PCV screen, replace it. They're cheap.

Oil all over the filter could also be a leak at the oil pressure idiot light sender. Its immediately forward of the oil filter, or it could be a leak from the O ring on the distributor base, the front intake seal, or a timing cover gasket, or none of the above. Gotta get it clean first.

[Sixlitre]

Here, treat yourself to some how-to picks on the screen replacement;

http://www.supermotors.net/vehicles/registry/9371/52482

This is what you're after;

http://www.supermotors.net/getfile/441096/fullsize/img_0035.jpg

This is where it lives;

http://www.supermotors.net/getfile/441105/fullsize/img_0049.jpg

Once you've got your PCV and it's screen changed up, think seriously about replacing the valve cover gaskets with FelPro PermaDryPlus blue silicone gaskets;

http://www.supermotors.net/getfile/443876/fullsize/img_0006.jpg

Probably be the last pair you ever have to buy for any 5.0 litre.

http://www.supermotors.net/getfile/443878/fullsize/img_0012.jpg

read up on the valve cover gasket change;

http://www.supermotors.net/vehicles/registry/9371/52676

and the intake pull, here;

http://www.supermotors.net/vehicles/registry/9371/52481

Sixlitre

[SouthernLincoln]

Thanks for all the info and advice guys. This thing has a seriously bad oil leak. When i said massive, it'll go through a quart of oil a day!:eek: I've never seen such an oil leak.

Odd thing is that once i had it up on the lift, and looking at the undercarriage the only part of it that seems to be coated in oil is the drivers side. I still haven't determined where its leaking at... even after cleaning off the entire underside of the car.

Guess today i'll tear it apart again and see what i can't find out.

[87 town]

Thanks for all the info and advice guys. This thing has a seriously bad oil leak. When i said massive, it'll go through a quart of oil a day!:eek: I've never seen such an oil leak.

Odd thing is that once i had it up on the lift, and looking at the undercarriage the only part of it that seems to be coated in oil is the drivers side. I still haven't determined where its leaking at... even after cleaning off the entire underside of the car.

Guess today i'll tear it apart again and see what i can't find out.

Just for the heck of it, check your coolant and make sure it isnt oily or dark brown which may mean that oil and coolant is mixing due to bad intake manifol gasket. A qt a day is a huge amount to loose. But worth cheking the coolant as a possible troubleshoot...

[SouthernLincoln]

Well to post an update i still haven't figured out yet where the leak is. I just got around to buying a new oil-pressure sensor and a couple cans of Engine degreaser. Tomorrow i plan on swapping the sensor out while doing an oil change just to make sure it isn't the oil filter also. I might check the oil pan bolts while i'm under there... Just to see if they just might be loose. Also i have a new pcv screen going in at the same time. I figure if i attack it from pretty much all angles i just might get it fixed.

[Elemino]

Well to post an update i still haven't figured out yet where the leak is. I just got around to buying a new oil-pressure sensor and a couple cans of Engine degreaser. Tomorrow i plan on swapping the sensor out while doing an oil change just to make sure it isn't the oil filter also. I might check the oil pan bolts while i'm under there... Just to see if they just might be loose. Also i have a new pcv screen going in at the same time. I figure if i attack it from pretty much all angles i just might get it fixed.Save yourself all that trouble and just change out the PCV screen first.

[SouthernLincoln]

Well i pulled out the pcv screen. That thing was freakin' Filthy! I didn't have one to replace it so i'm running the car without it. So far i've noticed a better idle...and the trans isn't so rough switching between gears. Also i don't see or smell any tell-tale smoke when the car is shut off.

Is there anything bad that can happen if run it without that screen for a little while? Also, what part number do i need when i go to buy a new one?

Thanks guys, i even read the tech article, and i never would have thought that a little thing like that could cause so many issues.

[Elemino]

I couldn't tell you what the part number is, but I bought mine at Pepboys. Worse case scenario you have some oil running though the engine which isn't so bad as long as it doesn't get out of control. In fact I believe some guys on here decided not even to replace the thing. Me on the other hand, I'm running expensive $6/qt Mobile 1 Extended and to not use one is out of the question. But, sometimes you have to believe what the forum says. I tried a lot of stuff and finally gave in and it was the PCV causing my problems too.

[SouthernLincoln]

I scrolled back up and caught what i think is the part number in one of Sixlitres pics. Hopefully this friday i can swing by a parts place and snag one.

As for the oil thing, while it had the leak i had to feed my baby the cheap stuff, ain't no sense in wasting it right? Guess if i don't notice a continued use of oil i'll go back to my Castrol GTX 10w30.

[gadget73]

I was getting oil in my upper intake when I didn't have one installed in my car. I found this out when I pulled the upper for something else and oil started running out of it.

[SouthernLincoln]

Well the filter screen abated the leak somewhat, but its still leaking oil. Guess i now have to get into the nasty stuff to stop her from droolin' everywhere.

[Elemino]

Have you washed your engine since you took out the filter? It could still be dripping from the engine.

If you had to pick a place to start my choice would be the valve cover gaskets. The silicone ones are probably the best, like the ones Sixliter recommended.

[87 town]

Well the filter screen abated the leak somewhat, but its still leaking oil. Guess i now have to get into the nasty stuff to stop her from droolin' everywhere.

I agree with Elemino about the valve cover gaskets and if it still leaks after that you can go from there and feel good that you have new gaskets on there in any event.. Or just do a "good" degreasing and watch for the specific spot of the leak cuz it is soooo hard if not impossible to find the leak on an already oily/greasy area.
I was amazed a week ago on a different car I have. 66 chevy impala. i'm degreasing and detailing the engine and notice a leak coming out from the upper intake manifold gasket, right in the front of the block, rolling right there on my new orange engine paint in a specific spot.
I looked around and found that I had a "serious kink" in the hose connected to my in line pcv valve. Got rid of the kink in the line and that leak was stopped completely. Good example of "blow back" related to a dirty/clogged/kinked hose, etc PCV vale or connection.

[Ivan D.]

I'm one of those who chose to not run a PCV screen anynmore, I lose about a quart of oil per 2000 miles, which is alright cause I get my oil in 6-packs anyways, and I change it every 3500-4000 miles. I have pulled my upper intake on several occasions after removing the screen, never saw a drop of oil in the air passages. Guess it depends on the particular car...