After returning from a 600 mile trip where I was towing about 6,000lbs (including the trailer) I noticed an oil leak.

The vehicle is a 2003 6.0L PSD 4X4.

The oil appears to be coming from the rear of the motor, high enough to leak down both sides of the transmission.
However, it appears to be concentrated more heavily on the drivers side.
My initial thought was the "Rear Main Seal", but I am not really sure.

The oil level seems to be within tolerance (not much has been lost).
The oil is NOT milky (does not appear to have water in it).
There has been no noticeable change in performance (never missed a beat coming home towing a 6,000lb trailer 600 miles).
There has been no decrease / increase in oil temp.
It appears to drip only when the vehicle is running (it will leave a couple of small puddles of oil when parked or left running idle).

Attached are a few pics that may provide some insight as to what I am talking about.
My apologies for the poor quality, they were taken at night with me laying underneath the truck.

Any input will be appreciated.

Thanks,
Cecil

 

Icp Sensor Back Of The Motor Drivers Side, I Noticed Some Drips On Driveway, And The Front Of Trans Case It Was Running Down That, I Think That Could Be The Source, I Had Mine Replaced Under Waranty When Cab Was Off For Headgaskets And Studsso I Didnt Do The Work,if You Have Any Waranty Left Get It In I've Heard Its A Bugger To Get To And Replace See My Gallary Of Picks Of Location On A 03 And The Oil Travel Looks Familiar. IT IS QUITE A BIT OF OIL THOUGH YOUR INITIAL THOUGHT MIGHT BE IT ALSO.Hope This Helps And Good Luck.

 

I had oil dripping down back of engine 2 different times and both times it was the CAC tubes came loose.

 

I agree with the ICP leaking. Mine is leaking again 50,000 miles is about there life span. The dealer replaced the first one. It requires a the use of a lift, a second set of eyes, a 36" extension, and metric swivel sockets. There is a tin shield that you have to take the bolts out of to get to the sensor. Don't try to remove the shield, just push it up high enough to get to the sensor. You will need to use the extension from the tail of the tranny over the top to get the bolts out. It took 1/2hr when we did it the first time.

 

Thanks guys!

I found this to be very helpful as well:

 

At idle, do you notice the engine surging? if not it is not a leak in the HPOP system. Even a loose oil filter cap will do this and I see it's not on the list. Should be added as 0.0001%. It happened to me and scared the heck outta me as I thought it was the rear main seal, turns out the quickie lube forgot to replace the o-ring on the oil filter cap.

 

No surging.
It idles fine.

 

Then you can rule out that the leak has anything to do with the HPOP system. If it was CAC tubes you should notice some loss in performance? Doe it start fine? Maybe get the dye test done or wash the engine bay and keep a close eye on it. It wouldn't say that it would be the rear main seal because that would leak out the bottom rather than both sides of the engine. I'd say it sounds like it is something near the top center of the engine.