Any Ideas? I just started noticing this, truck has around 35k miles, and sometimes it smells like diesel BAD in the cab, then sometimes it goes away, generally it goes away on the freeway 60+mph.

Can anyone give me a starting point to look for? I have no leaks, and nothing seems moist in the engine bay...

Thanks for any and all input!

 

Make sure your floor plugs are in good and tight. Does your exhaust sound any louder or same as usual.

 

Floor plugs are tight as far as I can tell. They have never been out. Exhaust and engine noise may be a little louder. You thinking exhaust leak? I dont know, it really smells like raw diesel vs. exhaust.

 

Have you checked the fuel lines from the tank forward? There is also a vent line from the fuel tank that vents right behind the air cleaner canister. There is a diesel line drain valve in the bottom of the driver's front wheel well. Check all of them. There is also a rubber fuel line in the valley of the block going to the IP. It is hard to see a leak up in there but that line can split and leak. I assume you haven't noticed any small puddles under the truck.

 

Do you smell it after a fill up?

 

Yes and no, filled up then drove 150 miles then started up a mountain,going up around 5000 feet, smelled it the whole way up the mountain (this is when I initially smelled it, actually smelled like coolant and diesel) and the tank was half burned through. (Never smelled coolant again after this, could have been my nose playing tricks)

Then filled up, and smelled it all the way down the mountain.

Now with tank half gone, slight smell.

It is driving me crazy! If I could just see some moistness I would have a clue.

Whats that old saying... roll her in flour to find the wet spot? lol

 

PM hummech here on the forum. He can help you trouble shoot this.