92 Crown Vic 4.6L mysterious oil leak?

Your best bet here. This is where I got mine after much searching:

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Best price found and they ship promptly. Price is good on internet orders only. Ford price is well over $100US.

These engines have a very high rate of valve seal failure. The converter will usually mask the smoke as soon as the engine RPM comes up a bit.

Replacing the gaskets had no influence on the oil consumption other than stopping the leaks. I suspect your switch to synthetic oil resulted in cleaning sludge from potential internal leaks like the valve seals.

The valve seals can be replaced w/o tearing theengine down. It is rather time consuming. You will need a good air compressor and an adapter to pressurize each cylinder while you replace the seals. You will also need lots of patience and a good assortment of hand tools. As far as time goes, I am told Ford give 11 hours to replace the valve seals. I spent about 14 hours the first time not counting sleeping or breaks. I also have the necessary power tools available to do the job and there were no adult beverages involved. This is a job for a fairly well equipped intermediate to advanced DIY'er.

Reply to
lugnut
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One big problem with that vintage 4.6L is the tubing for the PCV. It becomes clogged over time and the condition of the PCV itself will not matter. This can also lead to leaking seals and gaskets. Removed the PCV tubing and make sure it is completely open and not crimped.

Reply to
lugnut

The plugs in mine burned very clean even before I replaced the valve seals. It was using a quart every 150 miles or about 2 qts. with every tank of gas. I wouldn't worry too much about the fuel mileage on it. Mine has always gotten aroung 21-22 local and 25 hwy. I have been using a set of standard copper core plugs in mine now for over 45K miles. I was going to replace them a few weeks back but, I checked a couple of them and they looked so good, I decided to be lazy and see how far they go before I change them. These engines seem to be as bulletproof as anything I've ever owned even when you are not finicky about maintenance.

Reply to
lugnut

I have a 92 Crown Vic with a 4.6L engine with 135K miles. Inherited the car in June from my late uncle who died in March 2004. When I got the car, the sides of the block was covered with oil and you could smell it burning when the block was hot. I figured it was coming out from under the valve cover gaskets, so I changed those. No more oil off the side of the block, and the oil level stayed constant. I had been topping off with whatever dino juice I could find in my garage. After the level stayed constant, I decided to do an oil and filter change - this time with some 10W-30 Amsoil. It immediately started to leak oil right around the oil filter mounting block and was blowing oil alongside the engine and up into the hood insulation pad - not a good thing!

So I went and got the gasket to fix this and found out that the lower radiator hose port also is part of that oil filter mounting block and that the gasket seals not only the in and out flow of oil, but also the coolant - not a good idea. But I replaced this and no more oil blowing alongside the engine.

But after a trip up north, I noticed that the oil level was still dropping - not as much as when the valve cover and oil filter mounting block gaskets were leaking, but still about one quart every 500 miles. I don't see a leak on the engine - top, side or bottom, so where it is going? The engine doesn't appear to smell like it is burning oil out of the exhaust - no blue or black smoke. Do these engines start leaking internally after a certain time?

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USENET READER

Reply to
<fitz773

I have a 92 Crown Vic with a 4.6L engine with 135K miles.

But after a trip up north, I noticed that the oil level was still dropping - not as much as when the valve cover and oil filter mounting block gaskets were leaking, but still about one quart every 500 miles. I don't see a leak on the engine - top, side or bottom, so where it is going? The engine doesn't appear to smell like it is burning oil out of the exhaust - no blue or black smoke. Do these engines start leaking internally after a certain time? ============== your first sentence says it all. when the 4.6 gets about 130 to 140k on them, the valve guide seals give out and fall into the pan. i have found that it makes no difference if you use synthetic oil or dino oil. it still happens. i'd have six cars with 4.6 in them. police pursuits, lincoln town cars, and mustangs, when they hit the number on the clock, they start using a little oil, and then it slowly creeps up from there. if you drive on the highway a lot, it won't go through oil that much, but the city traffic is where you will notice it because it will suck the oil past the guides from the high manifold vacuum. it will get down to a quart every 300 in the city over time.

question - ever notice the C.V. taxi cabs with the miles on them. that puff of smoke on start up from a stop light. that's the tell tale sign. watch yours after it idles for a while and see if you get the puff of smoke.

i've got one right now - a 92 lincoln, with 160k on it and it runs great, but if you let the engine idle, say with the air conditioner on this past summer, it will just sit there and puff a little bit and smoke until he drive off, then it will leave a 10 feet trail and clear up.

they make a tool to replace the valve seals without tearing the engine down.

hope this helps.

knowledge is power - growing old is mandatory - growing wise is optional "Many more men die with prostate cancer than of it. Growing old is invariably fatal. Prostate cancer is only sometimes so."

Reply to
c palmer

Can you give me a clue where you can get these tools for replacing the valve seals without tearing the engine down?

Also I haven't noticed any smoke from the engine - either at idle or when gunning the engine after a long period at idle. And oil consumption doesn't seem to vary whether I do city or highway milage.

But you see - the oil consumption hasn't gone down - it just seems to have changed from three external leaks (two valve covers and the oil filter mounting block) to something I can't see. I wonder if sealing up the external leaks somehow put ore pressure on something inside the engine that would leak internally - like the valve seals.

c palmer wrote:

Reply to
USENET READER

the PCV valve comes to mind.

YOuy might not see the obvious smoke, but I'd bet if you look back through the mirrors with the light at a certain angle, you'll see it.

I had bad seals on a 2.3 and used only a quart/1000 and it was very obvious when watched from the front

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Reply to
Backyard Mechanic

BTW... when you're using that much oil, it's real easy to forget and let the level drop to the point where the rings get starved whereupon the edges overheat and round ...

You're right, that oil has to go somewhere... if it's not going into the radiator, it's going into the cylinder.

Have you read your plugs?

Reply to
Backyard Mechanic

I checked that - the PCV valve seems to be OK - when I take it off the valve cover and shake it - it seems to work OK. Also, I have let the car run in my driveway and sit there alongside and check it out - no burning oil smell or appearance of oil smoke. Also whem I had the car up on a lift a couple of times and the engine was running, I could't see it.

BTW - when the car was gett> the PCV valve comes to mind.

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USENET READER

Reply to
USENET READER

if you want to know for SURE if you have any external leaks, get a dye trace kit. it is made up of a fluorescent dry - usually yellow in color that only shows up to black light.

procedure - put in oil and drive normal. then take black light and look for yellow dye leaks. works great, but sometimes it may not be what you want to see. i had a 302 doing basically what you are described and put the dye trace in it. that night i found 7 leaks - all of them were not a cheap fix.

BTW - i know autozone sells kits, but mine was under 20 dollars - minus light.

hope this helps.

knowledge is power - growing old is mandatory - growing wise is optional "Many more men die with prostate cancer than of it. Growing old is invariably fatal. Prostate cancer is only sometimes so."

Reply to
c palmer

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