This is my first post. I read quite a bit of the post on the site. Figured you are the folks to ask. I have noticed over the past couple of weeks a funny smell coming from under the hood. It is not an alarming buring smell, just smells different. i checked everything i could think of. No oil or any other fluid leaking, exhaust looks, and sounds snug. I checked brakes and tires look fine. My fear is that something wore out inside the motor and I am getting the smell from something I can't see. No codes, overheating, failures, just a wierd smell. Also, it has been pretty hot
(100+/-) here in New Mexico recently, maybe that has something to do with it. Thanks for any tips.

2004 Dodge 2500 Cummins HO

 

if its kinda of a rotten egg smell - batteries.
if its kinda of asweet smell - anti freeze.

 

Thanks. I checked those. Battery is good and Antifreeze level stays the same. I was poking around a little more on the site. I found an article that talks about a smell after the oil change. The smell did start after my last oil change. I had always had a local place change the oil (just was easier for me), I changed it the last time and used Shell Rot. oil. Quacker State had always been used before. Could this be the culprit?

 

That would probably be it...
http://dodgeram.info/tsb/2000/09-02-00.htm

or

https://www.dieseltruckresource.com/...=rotella+smell

 

Nothing better than Rosmella after a hard run!!!!!!!!

 

Sorry, I had chili last night

 

I had to change to Amsoil. That Rosmella gave me gas....

 

Thanks I think we found the culprit.

 

When i switch to royal purple 15w 40 it did the same thing and freaked me out big time, it hasn't been 300 miles yet but the smell is fading by the looks of it.