So when I put that oil cooler back in there I torqued the bolts to the rather wimpy factory torque specs, and then just a little more since it seemed too light. Well, it was too light. After about 300 miles of mild, non-towing highway travel, I noticed a light drip of oil under the truck and tracked it down to a leaky oil cooler! It was just barely seeping at the top of the cooler, between the cooler and the cover. So I went back through and really tightened down the bolts that were too loose, which was about half of them. Took it on another backroad drive and now there's no leak at all.

So if you have to do your oil cooler, recheck and retighten those bolts after a hundred miles of so, and loctite might be a good idea. I didn't use any because the Cummins manual didn't suggest it.

 

some thing to remember. thanks for the heads up.

 

Oh and then today, i realized that one of my drips has been coming from an oil filter that is LEAKING along the seam at the top! Wow! So I turn around and hurry back home leaving a trail of rainbow colored drops behind me. I returned the oil filter to NAPA, and got a new one. Put it back on, STILL getting a steady leak from somewhere. That one I traced down to the BRAND NEW oil pressure sending unit. It is just pouring right out the end of it! (yeah, I know, someone told me I would regret the NAPA sending unit, but Cummins is 100 miles away and NAPA is less than ten...)

*&#$!

 

glad you caught it when i was a fleet mech we had a couple rigs fry the engine when the end of the oil pressure sensor blew out dumping all the oil and the lite didn't come on because there was no ground.

 

yeah ,that was the last thing I expected from a switch with 400 miles on it. gauge still showed good pressure too.

It was leaking just fast enough to have let me get a good ways from home before all the oil would have been gone...

 

What sort of crazy-high oil pressure are you running? Probably a bad run of oil filters from the Wix plant. Not typical. I've had leaking seam problems with Mobil1 and K&N filters on other applications. Both are made by Champion Labs and are otherwise excellent filters.

 

Manufacturing quality control in the filter plants is pretty good these days, alot better than it used to be. But every once in awhile one still slips through. Could be any brand. I always check them real careful right after installation, just to make sure.

 

When installing a gasket or seal, I ALWAYS loctite the threads of any bolts to hold it in. Even the "smooth" Cummins engines vibrate enough to shake most bolts loose after time.

Daniel

 

Ended up ordering the sending unit from Dodge. No dealers stocked it, and although Cummins had one, they are almost two hours away. Dodge PN is 53030493, in case anyone else needs one someday. It is a superceded part number and it took the guy about 15 minutes to find it.

Hopefully that one won't leak! haven't taken the bad one back to NAPA yet; they are never very happy to see me these days. Bad oil filter one day, bad sending unit the next...