I’ve had an oil leak ever since I got this truck but have been fixing other stuff first and have got to the oil leak... so now, I’ve pressure washes and cleaned the the undercarriage real good and this is what I’ve found... my question is what is this? (See pic) thx in advance for y’alls help!!!

16 minutes ago, Goonas2 said:

I’ve had an oil leak ever since I got this truck but have been fixing other stuff first and have got to the oil leak... so now, I’ve pressure washes and cleaned the the undercarriage real good and this is what I’ve found... my question is what is this? (See pic) thx in advance for y’alls help!!!

 

Looks to me like the oil cooler is leaking. It could be possibly the the gear cover housing leaking and the oil blowing back since it's oily around the front of the a/c compressor.

 

 

So cooler gasket replacement or go ahead and get new cooler that comes with gasket?

I would just do gaskets unless you see oil in radiator. Just drain the coolant and remove the oil cooler / oil filter housing assembly, replace the 2 gaskets, install oil cooler / oil filter housing assembly, torque all bolts to 212 in. lbs. Fill coolant. Start engine and verify repair.

very good, thank you!!!

Make sure not to get any gasket debris in the oil ports. A tip gave to me by another member!

Is oil cooler gasket a common issue with leaks on this engine?

Edited November 10, 20186 yr by Goonas2

Dont know how common it is but I just crossed 456k miles on mine and thats one spot that has not sprung a leak. My front gear case was leaking pushing oil back that way and maybe the front main seal. I did both not to long ago.

If you still have the puke bottle on the front of motor that can contribute to oil blowing around.

Mine just past 360k miles and started a coolant leak at the top corner.

2 hours ago, Goonas2 said:

Is oil cooler gasket a common issue with leaks on this engine?

 

I've seen quite a few B and C series Cummins develop external oil leaks from bad gaskets. Can't say it's common but does happen.

 

This was an ISC that had an external oil leak from the oil cooler gaskets. BTW. I always take pictures when I'm taking something apart to keep straight where different types of bolts go. 

 

2 hours ago, dripley said:

Dont know how common it is but I just crossed 456k miles on mine and thats one spot that has not sprung a leak. My front gear case was leaking pushing oil back that way and maybe the front main seal. I did both not to long ago.

If you still have the puke bottle on the front of motor that can contribute to oil blowing around.

 

I have seen bolts come loose from vibration on the front gear cover housing causing oil leaks on many B and C series engines also. I recommend blue loctite on the bolts on the front gear cover housing.

2 hours ago, 04Mach1 said:

I have seen bolts come loose from vibration on the front gear cover housing causing oil leaks on many B and C series engines also. I recommend blue loctite on the bolts on the front gear cover housing

Mine were all still tight when I took them loose so I did not use any loctite on them. I will check here in the near future and see if any are working loose.

If it were me and I have chased leaks the same. I would get a couple cans of brake clean and rags and clean everything and the hard to reach areas, then start truck and get underneath with a pin light and check everything, usually the leak will present its self.  just because you have oil drips off something don’t mean it’s leaking. Gravity and wind dictate where oil is going to go.

I have oil like this..  no idea where to start..  it’s everywhere...  yet only lightly drips on the driveway.

 

 

47 minutes ago, portlandareae28 said:

I have oil like this..  no idea where to start..  it’s everywhere...  yet only lightly drips on the driveway.

 

 

Power washer, brake clean, rags, and a lot of patience laying under a running engine looking for the origin of fresh trails of oil.

Edited November 11, 20186 yr by 04Mach1

9 hours ago, 01cummins4ever said:

If it were me and I have chased leaks the same. I would get a couple cans of brake clean and rags and clean everything and the hard to reach areas, then start truck and get underneath with a pin light and check everything, usually the leak will present its self.  just because you have oil drips off something don’t mean it’s leaking. Gravity and wind dictate where oil is going to go.

 

I agree, fluid leaks can be hard to pin point. Don't guess or assume....you want to "know" before you start throwing parts at a repair.