What could THAT be?????

[EMD-Run8]

Change my oil today at 3200 miles (12 Qts of Rotella). I figured the factory oil probably had some assembly lube and whatever else in it so what the heck, I'll change 'er till it's Amsoil time. However I wasn't expecting the coolant-looking substance that seemed to be laying on top of the oil in my drain pan. It looked as though it had come out toward the end of the drain. It didn't look to be a whole lot. The factory Dodge coolant isn't green though, so I don't get it. Could it have been some regular coolant used when/if the engine was test-run at the Cummins factory? Was it just some phosphorus residue from the oil itself? I hate to sound worried (I'm also eye'in a rear main seal leak) but it does make you wonder. The truck sure runs good though. Any help appreciated.

 

[TCDiesel]

oil

I known this may sound stupid,but was the contamination in the drain pan,and than floated to top.

 

[Matt400]

Coolant is heavier than oil so it would have been the first thing you saw when draining. Could have been some sort of tracer UV dye that was installed to locate a leak before it left the factory. I wouldn't worry about it unless you see it again at the next change.

 

[EMD-Run8]

Thanks fellas. I thought about it being coolant from previously but I haven't had any in the drain pan that I know of. I'll keep an eye on it. Also, about that rear main seal, I've added some length to the breather hose ( 12" maybe not enough?) because I thought it may have been coming from there. The oil seems to be dark and icky while that on the dipstick was pretty well clean. It looks to me now though that it is coming from the rear main. You can see the wetness way up in the engine/transmission joint area. Could oil from the breather be swirlin' way up there from under chassis wind/turbulence? I'm thinking that I'll wait until I switch to Amsoil since it helps seals to swell a little more and maybe seat better. I should notify the dealer now though and let them know about it huh? Hey, thanks again, Dave

 

[dan.poitras]

have changed oil in several new CTD and found all of them had a greenish tinge to them. Probably a tracer dye as mentioned before. Gone at the second oil change.

 

[rbattelle]

I thought I recalled hearing something in here about the rear main leaking slightly on new trucks. Is it possible the seal just needs some time to seat better?

 

[Got HO?]

Rear main

Seems that Dodge (or Cummins) uses a lot of grease on the starter bendix & ring gear when building the trucks. I had a stain on the bellhousing & cover plate after about 1k miles. I removed the plate to inspect it & found grease slung fron the ring gear in a line on the inside of the bellhousing. Cleaned the excess & haven't had any residue re-appear.

 

[Prairie Dog]

All Cummins engines, rite up to the big boys come with that green oil. It's got dye in it for locating leaks with a black light if they occur.

 

[DocDetonancour]

Changed mine last night and everything looks dry.

 

[Blakers]

Originally posted by rbattelle

I thought I recalled hearing something in here about the rear main leaking slightly on new trucks. Is it possible the seal just needs some time to seat better?

What would a main seal leak have to do with green oil?

 

[EMD-Run8]

Thanks again y'all. It was a bright green color so that's probably it. I'll keep an eye on the rear main leak (if that's what it is).