Ive got a 2003 excursion with the 7.3 with 250.000 miles, dont have any problems with it, No leeks i have a full 4in turbo back exhaust and banks 6 gun tuner, Every now and then when i start it in the morning I get a puff of blue smoke, that it other than that there is none, do you guys have any idea if its somthing to worry about? its been warm lately so i havent really been waitting for the glow plugs to warm up or whatever, could that be it?

 

Blue smoke at startup is a tell-tale sign of worn valve seals. Oil seeps down while the engine is off and burns off on startup. The real fix is new valve seals.
You could try adding some Sea-Foam which is known to refresh seals.

BTW, some people may dispute Sea-Foam. It's simply a suggestion on my part, please respond accordingly.

I hope this helps

 

it doesnt do it every start up, this is the second time ive had it happen in a month

 

if that was the case wouldnt it happen everytime i start it after its been sitting?

 

Just an Fyi, it eats seals on our trucks I can attest to this....

I thought I had a stuck injector a few months ago and ran Sea Foam in the oil and fuel and paid for it dearly. Things that normally didn't leak on a 7.3 leaked...The Oil Cooler, LPOP, ALL the seals on the fuel bowl...while I did most of the work myself, the oil cooler was the most expensive of the ones I had done (LPOP and Oil Cooler).

My truck used to do it during the winter time and if it sat in the cold for a few days. Try either using some Bio (B5-B20 should do it) or some Power Service Diesel Kleen, gray bottle. ULSD is naturally dry and not what our trucks were designed for. The were designed for the well lubricated LSD and ran great on that stuff. While our trucks can tolerate ULSD, it's important to keep things lubed up.

Walmart.com: Diesel Kleen Plus Cetane Boost, 16 oz: Automotive

 

so it could be the fuel im using thats causing this?

 

It's the fuel we all have to use, it's just dry in comparision to when these trucks were new.

 

Sorry to hear of your problems.

If you have an old seal, I volunteer to soak it in SeaFoam to see the results. Ethanol eats seals, but an oil based product shouldn't.

Diamond-X