big oil leak

low ufo · #1 (**permalink**) 07-05-2007, 10:53 AM

I just put in my newly rebuild 428 FE bolted up to a new TKO. Lifting it into the car (at a @30/40 degree angel) I noticed it starting to drip oil on the front side of the fly wheel, thought it was just a loose oil pan gasket. Anyways, I only had help to put the motor and tranny in at the time so I continued with the installation. Before starting it up I noticed a good amount of oil on the floor and after getting it running and setting over night I had a large puddle on the floor!! It's not the oil pan gasket I checked this morning. The question is by tilting the engine during installation and it leaking like this would this be a common indication of a bad rear main seal or maybe a cam seal. This was a constant drip every 5 seconds or so during installation. If in fact it is the rear main seal all the posts that I've read indicate that I can leave the engine and transmission bolted up and just drop the pan to replace the rear main seal. Any suggestions or comments.

LOW UFO

patrickt · #2 (**permalink**) 07-05-2007, 12:05 PM

The most common leak location in an FE is the back of the intake manifold. A leak from there is often times mistaken for a rear seal leak. Can you see any sort of leaking from up top staring down the back of the engine?

RedCSX1 · #3 (**permalink**) 07-05-2007, 04:06 PM

OR it could be the rear galley plugs. I had a 427 leak like crazy sitting on the dyno. This where the leak was found. First determine that it is not leaking from the rear of the intake. Then if that is not the case move to the back of the block.

Ford428CJ · #4 (**permalink**) 07-06-2007, 08:04 AM

Could be the rear main seal. And if it is Pull it and silicone it is what I do LOL. I bet it is a rear main "IF" you didn't prime the oil system/run the engine before install!

double ugly · #5 (**permalink**) 07-06-2007, 08:21 AM

A leak that bad should be easier to find than a slow leak, I would think.
I chased a small leak on a 428 PI for months. Replaced pan gasket and rear main. No change. Finally pulled the tranny and bellhosing etc and found a leaking galley plug. My leak was only the size of two silver dollars after sitting overnight. Hopefully Woodz will chime in.
John



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