Oil leak...but where?

[Robt34]

I noticed a few drops of engine oil on the garage flood today. Climbed under the truck and snapped some pics. I can't tell where its coming from. Oil plug is tight, so are the bell housing bolts. It does seem to be around the oil pan/starter area. Any ideas on possible causes? Thanks in advance for the help

[Ray@NP]

looks like it just may be the oil pan leaking, also check the oil pressure sending unit and valve cover gaskets

[Robt34]

Yea Ray those were my initial thoughts when I climbed under the truck and saw the oil around the rim of the pan but it seems to be concentrated only on one side of the pan near the oil filter/bellhousing side. If it was the pan wouldn't it be all around the rim/lip of the entire pan?

Another clue it may be the oil sending unit is there is oil that has been slowly collecting under the intake. Then I read it could be leaking down from the sending unit on to the oil pan and bellhousing making it appear like its the pan.

I will also pull the bellhousing cover and take a look at the flywheel area and hope it's not the rear main seal.

[Robt34]

I forgot about the valve covers, I'll check there too.

[GMCwantsLS1]

Also check the dip stick tube.

[darnie1987]

i have the same issue, now that u mention it i think mine may be that sending unit i inspected it a few times because it still has me thinking it could be it...

[Robt34]

I changed the sending unit yesterday, I will climb under there today and see if that was it. If not I will have to try the filter adapter gasket thing, it seems to start from there if its not the sending unit or cam sensor leaking down from the top of the motor.

[Robt34]

I felt around the oil sender and there wasn't any fresh oil but I changed it anyway, 10 year old part it was probably due anyway.

I couldn't get my hand down far enough to feel around the cam sensor. There is alot of caked up oil and dirt under the intake that I was sure was the oil sender but the leak persists.

So, oil sender is good, valve covers are dry, no fresh oil on the dipstick tube either, next to try is the oil filter adapter or possibly the oil pan.

I popped the cap on the bellhousing and it was dry except for a small amount of oil residue on the back wall of the motor. I had to touch it just to notice it. Is this area supposed to be completely dry of oil? Right now its very faint.

I'm leaning towards something on top of the motor due to all the oil/dirt under the intake. Posting more pics in a bit..

[Robt34]

Two shots of the oil sender unit, oil/grease caked but no fresh oil that I could see or feel.





Here is a shot of the valley cover caked in oil/grease


Pic of intake rails

[Botlfed]

Rear main seal.