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I have a 1986 F150 with an oil leak, but I don't know where the leak is originating from or how to fix it. these are some pictures to show what it looks like underneath.
Could really use some help figuring out how to fix it and where the actual leak is coming from.
Look at your valve cover or covers depending on if it's a inline or a v8?. Also could be your intake manifold. How many miles? Any gasket work on the motor done to it? Follow the trail of oil. A good head light or any good flash light helps a lot.
Stick your finger in those oil drips. Is that oil red? If so, it's transmission fluid. Just to make sure, go up and pull the dipstick on the power steering fluid and see if it has red fluid in it. If it does, then it could be a leak from it, but if the power steering fluid is light brown, then the red fluid is the transmission fluid. Looks like your front seal is leaking a little bit. Also check the metal lines going to the radiator. That's the tranny oil cooler, and if they are leaking, they can blow red tranny fluid back all over everything.
Look at your valve cover or covers depending on if it's a inline or a v8?. Also could be your intake manifold. How many miles? Any gasket work on the motor done to it? Follow the trail of oil. A good head light or any good flash light helps a lot.
Its a V8 with 148k miles. I am the second owner, but I don't believe there has been and motor work done to it. Also, there is no real trail of the oil, what you see in the pictures is everything I can see.
The rest of the oil is minor oil leaks from the engine. You will need to clean the engine up really good and then keep an eye on it to find all the leaks. But if this engine is the original one, it probably leaks all over the place. It's had slow leaks for a lot of years, that's why it's all black. That's dirt sticking to the oil. If you had a major leak, there would be areas that are clean and shiny. The detergent in the oil will clean off any of the dirt if you had a bad oil leak.
I have the same problem, looks pretty much identical underneath with the oil. I bought a new oil gasket thinking the transmission pan was the oil pan (I know very little) because the seal kind of pokes out from the seems. But quickly realized my mistake looking at the part. What exactly did you do to fix the oil leak? It looks pretty good for an old truck so it hasn't been ran too hard but most of the stuff on the truck is original so I'm not sure where it might be coming from.
Last edited by Alistair 1924; 12-03-2016 at 04:29 PM.
Reason: Typo
...most of the stuff on the truck is original so I'm not sure where it might be coming from.
Welcome to FTE.
My first thought is the valve cover gaskets are gonna be responsible for a lot. Following that could be a lot of things... water pump leaking coolant, front and rear crankshaft seals, oil pan, intake manifold, oil pressure sending unit, there are several possibilities. Best thing to do IMO is clean everything up and then watch all the various possible sources.
The water pump supposedly was replace pretty close to before I bought it so I dont think it is that unless something is loose involving that? I'm gonna clean up the oil residue on it when I get off work and get an engine guy to help me. The gauge goes down drastically to L going up even the smallest of hills. I've noticed more oil in the garage lately but figured most of this (if the oil is leaking because of an uphill incline) would make sense because my driveway is a steep hill.
Judging from the pics, it could be a rear main seal and or oil pan. I'm 99% sure mine has a leak there I need to fix and I have pretty much the same leak pattern..
Judging from the pics, it could be a rear main seal and or oil pan. I'm 99% sure mine has a leak there I need to fix and I have pretty much the same leak pattern..
If you have replaced/fixed every gasket/leak on top of the engine, then I may agree. But any leak up there will run down and look like a rear main.
Believe me, you do not want it to be the rear main if you can help it. I would clean, double check, clean and double check before deciding it's the rear main.
If you decided it's the rear main, and it's a very slow drip, I have had success with those engine sealers they sell. They will slow the leak down. I have also found these high mileage synthetic blend oils will make the leak worse. Try a regular conventional oil the next time you change it, and you may find your leaks reduced.
I know the water pump won't leak oil but there was a suggestion it was a water pump leaking coolant. I know its an oil leak, I just dont know where at yet, it had a small coolant leak in one of the hoses after I got it, that's fixed now.
If you have replaced/fixed every gasket/leak on top of the engine, then I may agree. But any leak up there will run down and look like a rear main.
Believe me, you do not want it to be the rear main if you can help it. I would clean, double check, clean and double check before deciding it's the rear main.
If you decided it's the rear main, and it's a very slow drip, I have had success with those engine sealers they sell. They will slow the leak down. I have also found these high mileage synthetic blend oils will make the leak worse. Try a regular conventional oil the next time you change it, and you may find your leaks reduced.
Thanks Franklin. I know it's going to be a pain to change and I really hope it isn't either. I did recently change the oil with the high mileage synthetic with half a quart of Marvel Mystery Oil. It looks like I may have to change that first to see if it helps. I've done all the seals on top already and I can literally see the oil slowly coming from in between the oil pan and transmission so my hopes aren't to optimistic on this one lol. The oil pan gasket looks to have been changed recently as well.
02-27-2015, 04:48 PM
