I have had an oil leak fo a while now in my 300 I-6. I have changed the oil sending unit(plugged it), valve cover gasket and the rear main seal, not to mention all the other parts that needed to be replaced like the flywheel,clutch,pressureplate,u-joints and bearings. Anyway after all of that I ran it and it started to blow out the back of the top of the engine. I have ruled out the head gasket,oil pan/gasket because of the location and the amount of oil comming out. I am starting to think that I have a hole in the valve cover or in the block. I have washed it down with a pressure washer to clean it up but still no luck at the excact location. I do have blowback in the engine that flows into my air cleaner but it is nowhere near the main problem.The leak is comming from the top rear and spilling down the bellhousing and dripping from the tranny. Little help anyone?

 

Happy 4th fellow Bronco brother!!
I see from other posts that you may put in a 460..that would be a great upgrade. Now for the problem, if the rear main is good, I would check the oil plugs in the back of the engine. I think I have the same problem with my rebuilt 302 EFI, I just have not had time to take out the tranny, transfer case and all the other garbage to get to them. Maybe within the next few weeks! Let me know what you find.

'86 Ford Bronco xlt
4" Rancho lift
33" Duellers


"Big Trucks Save Lives!"

 

I did not see any oil plugs in the back of the engine only a water plug. I made sure I checked when I had everything pulled out. Any other ideas?

 

It could be the intake manifold gasket leaking.They are prone to leak at the corners where the manifold gasket meets the head corners.Also you might want to check the pcv system if you are getting oil in the air box.

Billy

 

Have to agree with CajunB. My leak turned out to be the intake manifold. However, it wasn't quite so simple because one of the bolts had broken, and the dealer had to have someone come in to build the bolt back up to the point where it could be turned and removed. Hopefully, you will find your leak to be something simple and cheap.