Oil Leak Question 88 F250 7.3L
 

New to this truck and the 7.3L... I have an oil leak that covers the bottom of the auto trans.. I can't see anything from the top other than the back lower corner of both valve covers have leaks.. I crawled under it to try and see where the oil was coming from... Both sides look like the leak running onto the trans is coming from up top from where the trans bolts to the block.. Can't see up in there.. Is it common for a leak to come from something up there??? Brings to mind the valley leak problems of the 360 and 390 FE engines... Don't want to bother with the valve cover gaskets if there is something more major...


Thanks...

The oil pressure sender is right up on the top back of the engine. Its common for the leak to be there. Also, the valley pan drains through the rear. I believe the drain port is on the passenger side of the engine, but can't remember exactly where. If your return lines leak, the fuel can drain out the back, but pick up dirt and grime and look black like oil.

Thanks. I checked the IP and although there is a little bit of a leak, there isn't a whole lot in the valley pan. Looks damp with diesel but nothing really running down the pan. Going to pull the air cleaner today and see if I can get at the oil sender unit. Is it at all common for the valley pan to leak at the back where it sits on the block and need to have the gaskets replaced? When I got the truck the kid said it had 185k on it..

Thanks..

Don't forget to take some pics!!! And welcome to the diesel side of FTE!!!

Oil Leak Question 88 F250 7.3L
 

Sorry, I don't know how to get pictures embedded in messages on here. Anybody know what socket to use to get the oil sender out?? It appears to be about 1 1/16 but my 6 point won't work.. Was wondering if it needs to be a 12 point.. My existing one looks like part number F1811 on the OReilly Auto parts website and the one another auto parts house gave me as a replacement looks like 2-8141..

When I did mine all I used was a small pair of channel locks....

X2, its not that tight.

i got mine out with vise grips. i wasn't gentle with it since i was replacing it with a mechanical gauge tho. if the valley looks damp with diesel that means there was diesel getting down in there and who knows how long its been draining down through there. the valley pan drains out the back of the engine and like the other guys said diesel will pick up dirt and dust and look like black oil.

Not a lot of room to grab it and a bit nervous about snapping it off so was hoping there was a socket answer... The valley just looks a little damp so not enough to be at the level I see on the bottom of the engine... The real leak looks like the valve covers in the back lower corners.. Have them changed so now will need to put some miles on it and see what it looks like... I have to make a 700 mile round trip this weekend so will be a good check to see if I still lose oil..

There is a special socket for the sender. Usually a snap on type item.

Yup, that's kind of where I ended up with it tonight.. Conventional sockets just won't work.. Can't even get slip joint pliers on it.. Has to be a socket to get it out... Guess I will have to look this weekend.. I live out in the sticks so closest city of any size is over an hour away..

I bent up a 9/16" similar to a distributor wrench, but the open end to get mine out. The part you thing is 1 1/16" is just the crimped base, i made the same mistake. But like others have said it will surprise you how not-tight it is. You may be able to get a stubby 9/16" on it, but the way it sits in my 79 it was no doin.

Funny you mention a fluid leak on a 7.3. Believe me, yours is NOT the only one! Between 35 gallons of fuel, 12 qts. of oil, a coupla' gallons of trans fluid, 5 gallon coolant system, over a gallon of diff oil, and some R-134, if something didn't hit the ground, I'd be wondering why it's not marking its territory!

On my '91 F-250, I fixed a couple of fuel leaks over the last week or so. When the fluid hit the ground, it was dark enough to look like oil. My schraeder valve was seeping a little, the fuel return lines were wet enough to have been seeping for a while, and the fuel heater was leaking from inside at the spade connector. After stopping these small leaks, nothing is hitting the ground right now except a couple of drops of trans fluid from the shift shaft seal - gotta' get that one fixed on my next fluid change.

Know what you mean.. I had to put in an injector seal kit and then rebuilt my fuel heater.. That stopped those leaks.. I don't think the oil sender is actually leaking (really hard to see) but the valve covers were definitely leaking.. With those changed, going to clean the back and bottom of the engine and bottom of the trans to see if there are any other leaks..

Tighten up your rocker cover bolts a bit and the leaking should go away. Almost every 7.3 I have seen leaks from there. Replace the gaskets if that doesn't fix it.