6.7 OIL FRONT/COVER OIL PAN LEAK

Larryforce · December 19, 2017

Good morning everyone,

I am working on a 14 f450 cab and chassis with an oil leak that appears to be coming from the upper oil pan, i can also see some minor leakage of the front cover seal. i can also see oil starting to seep out from between the bell housing almost the whole way around (except at the top from about 11 oclock to 1oclock). I just finished pulling the transmission and there was a puddle of engine oil in the bell housing/ the rear of the engine covered in oil, the crankshaft seal appears to be dry behind the tone ring.

I am thinking of replacing the rear cover seal, but am reluctant. When i said the front cover war leaking i was told that they don't leak and our dealer has never done one, and the techs at our sister dealers have never done one either.

Have you guys seen a rear cover leak oil? or is it most likely coming from the rear of the upper oil pan?

This truck has been repaired for this concern 4 or 5 times(not by me) over the last 3 years. the first tech resealed the galley plug in the front of the oil pan it has had the upper oil pan done 3-4 times, and once it was washed off and no leak found after test drive. I really don't want this one coming back again.

Keith Browning · December 21, 2017

I would tend to think that after several repair attempts the upper pan is not likely the suspect source. ou are probably right in thinking you need to reseal the front cover. I have yet to see one leaking either but that does not mean it's not. I would have dye tested this one...

KDS · December 21, 2017

Yes, Dye would be my suggestion also.

It has been very helpful in determining leak sources.

BigWalt · January 10, 2018

check upper pan rail for flatness, especially on driver side... I have seen them uneven / warp , starting from the front all the way to rear... hope you got something like large straight edge to check.

Larryforce · January 11, 2018

Thanks for the reply. I ended up doing both front and rear cover seals and the upper oil pan.

I had the straight edge out to line up the front cover to the block, I never thought to check for flatness across the upper oil pan.

Here is a picture of the front cover seam. Another tech thought that the oil could be wicking up the seem, but I wasn't confident enough in that assumption to let it go without changing the seal.

Edit: the top of the picture (the bottom of the bore scope) is the top of the engine.