5.0L oil leak, can't find it please help!!!!

[aaron5140]

I am new to this forum but i have a '92 t-bird sport 5.0L and the threads i have read so far have been very informative and helpful, so i am hoping i could get some advice. i have a fairly bad oil leak(been dumping in a quart every 4 days) that is on the drivers side toward the back of the engine and it drips onto the catalytic converter right at the end of the exhaust manifold causing smoke and that bad burned oil smell when i am at a stop. i have been under the car and above it and for the life of me i can not find this leak. the only place above the catalytic converter that i can find any oil is on the oxygen sensor on the back tube of the exhaust manifold right where the 3 wires come out of it.....the valve covers and heads are clean. is it possible it is leaking out of the back of the intake manifold? or where could it be coming from? any help is greatly appreciated

[91_T-Bird_HO_5.0]

it could posibly be coming from the intake maifold, but it could also be coming from the rear main seal, i had the same problem, but my front and rear main seal blew out, how many miles do you have on the engine, cause if you do have to replace the rear main seal, i'd recomend a complete rebuild, that's what i did, i replaced all the bearings, accept the cam bearings because they were find, the rings were fine too, i didn't even have to bore the engine, i had the cylinder walls checked and they were fine, a 302 can be put through the ringer and still come out fine, what i'd suggest it looking around where your flex plate is and see if there is any oil dripping from there, if you see oil there, take your starter off and then take the flex plate off and look up in there with a flash light, you should be able to see a little bit of the rear main seal, if you see oil there, then it's time to pull the engine to replace that, but don't just replace the rear seal, replace the front one as well, but if you replace the front and rear main seals, you are going to have to replace the main and rod bearings, cause when you releave the preasure from the main caps, the bearing isn't reusable or at least that's what i've been told by a couple of mechanics

[flewthecoupe]

Never heard of a bearing not being reusable.

[91_T-Bird_HO_5.0]

that's just what i've been told, once you releave the preasure from the bearing, the bearings will never align right again

[flewthecoupe]

there is virually no pressure on a bearing. They are "machine" fitted to the tolerance of the journals, i.e. .010 over bearings for a crank turned .010 under with a tolerance of typically .002.

I could be wrong but it's something I haven't learned or experienced.

[Bray Hill]

Just dont use any kind of leak sealer. Fix it in a bottle never works, and usualy causes more harm then good.

[danford1]

I have a 91 with 5.0 HO. Mine leaked just like yours.
It was the rear portion of the intake manifold gasket. It was dried out and popped out of place. I fixed mine . Not hard if you have done this type of work before. If you are a first timer, better get a few pointers from a mechanic.
I never use those cork or even rubber end gaskets. I always use a bead of silicon. Just clean both the block and intake with brake cleaner to remove all traces of oil. Run a bead about 1/4" in diameter on the block and on the intake. Wait about 20 minutes for it to tack up. Drop manifold stright down and torque bolts. I use long bolts with the heads cut off as alignment pins to slide the manifold down on. Then just unscrew pins (headless bolts) and replace with the intake bolts. 4 pins is all you need, or just 2 in opposite corners.
Let the silicon squeeze out and dry overnight. Next day trim up with a razor blade if desired. I use all colors of silicon. They all work just fine.
Cheers.

Danford1

[aaron5140]

thanks danford1, that makes alot of sense, i didnt really think it was the rear main seal.....how long on average does it take to disassemble everything down so i can get the intake off? any responses are appreciated

[danford1]

I can only work on a car a couple hours a night, after work. I did it in two evenings. I took it apart and started scrapping gaskets one evening, finished scrapping gaskets and assembled it the next evening.
I probably spent more time scrapping than anything !
Shove paper towels or rags in each port to keep the gasket fragment out of them. Then use shop vac to suck everything else up.
I left the distributor in and only took off what I had to. I never unhooked the fuel lines. I just flipped the manifold over with them still attached. My fuel line take apart tool wouldn't work, I couldn't get them off, thats why I left them connected. It was more of a pain scrapping gaskets off manifold this way but.... I got the job done. No more leaks.


Cheers.
Danford1