2007 Silverado Classic 2500 HD Duramax

• Jun 29, 2016

• #1

D

DrRx2005

Member

I've been noticing just a small, maybe 2 inch spot underneath the front of my truck of oil. Doesn't appear every time I drive it and park it, but I can't for the life of me see any signs of oil leak or drips underneath or on the engine.
Only has 22500 miles on it as I only use it to haul stuff when needed or when going hunting. Been driving a little more lately and started noticing this.
Any idea where to look or what it could be?

Thanks

 

• Jun 29, 2016

• #2

GoldDot40

Senior Member

Oil cooler line?

 

• Jun 29, 2016

• #3

D

DrRx2005

Member

?? It's basically right behind front bumper towards passenger side

 

• Jun 29, 2016

• #4

F

Firescooby

Senior Member

You sure it's oil, or could it be power steering fluid?

The PS lines are guaranteed failures

 

• Jun 30, 2016

• #5

D

DrRx2005

Member

It leaves a blackened stain on the concrete below it...disappears after a couple good rains.

I guess I assumed oil due to that, but did not actually see it still wet enough to test.

 

• Jun 30, 2016

• #6

lonewolf247

Senior Member

I would degrease everything under the hood, engine, all lines, reservoirs, etc. Also, get under the truck and do the same thing. Wear goggles, or safety glasses, to avoid getting something in your eyes. Then I would really start watching close to try to find the source. It could be several possibilities. It could be oil from engine, valve cover, coolers, lines, power steering, radiator coolant, diesel fuel. If it's 4x4, maybe front differential, even possibly cv joint, but would probably be more grease like.

Cleaning everything well, should really help to find the problem.

 

• Jul 15, 2016

• #7

chris41081

Senior Member

It's the trans oil cooler. I have the exact same truck with the same problem. There are 2 hoses going to the cooler, right behind bumper. They are rubber hoses with crimped on end fittings. They leak where the crimp is. There are some diy fixes on YouTube.

 

• Jul 15, 2016

• #8

chris41081

Senior Member

Used diesel oil won't disappear after a few rains.

 

• Jul 15, 2016

• #9

M

mmcneil

Senior Member

Sounds like your transmission cooler lines to me too. I've got an '06 and similar thing happened to mine around 95,000 miles.