Looking for some help from the masses again... I have a 2001 Excursion 7.3 that has about 156k miles on it. I have no power issues, rough idling, or anything noticeable but recently I have observed that when I accelerate after sitting at idle for several minutes (>5 min if less then that I don't see anything that I can tell) I have a small puff of blue smoke that clears up right away. I do not notice any unusually high oil consumption (yet) and my fuel mileage is great/good as it ever was. I have heard that alittle blue smoke after idling is not an issue but I have another 7.3 w/300k miles and i have never noticed this. Blowby on the excursion is very minimal, i recently put a plug in my air intake heater and went to 4" turbo back exhaust so while i had all that stuff off i got the camera probe and looked around the turbo to see how it was doing and everything looked great with no noticible oil residue or build up. Again i am comparing to a 300k mile 7.3 and my ex looks tight and it a whole lot cleaner in those areas.

Now for the one bad.... there was one time about a year ago when a mechanic put on an oil filter and it was kinked during installation from an oil wrench and it broke through while driving across country so that I had a low oil condition while driving. This exhibited itself as a significant loss of power and blue smoke out the exhaust until I could limp it to a nearby mechanic. I believe the issue here was air/low oil in the high pressure oil pump and I could not get fuel flow needed but I have never been able to understand the blue smoke. This situation was corrected by simply replacing the oil filter and refilling about 6-7 quarts of oil and I drove the next couple hundred miles home. The mechanic was a long time Ford diesel guy and he looked everything over really well and thought there was no harm done and the engine looked good. We did both a buzz test and a cylinder contribution test and everything was good at that point in time. I had just bought the truck so i do not know history prior to that other than all service was done by Ford and it was owned by an older gentleman who traded it in.

Ok so my questions are:

1. Does a little blue smoke after idling for several minutes need to be addressed? It seems like it is worse now (cloud is bigger then it used to be) but i could be over-reacting because its my baby .
2. If so what do yall think it is (injector orings or worn injectors)? I do not really have the means to do a compression test but i can try to figure out some way to do that in case everyone thinks i need to check rings better then oil cap blowby test.
3. Anyone have any other recommended troubleshooting ideas?
4. Can any of you explain my blue smoke under load during that low oil condition? Only places i can see it coming from is either by the rings (THAT scares me) or coming through the injectors.
5. If/when i replaceinjectors do i move from my split shots to singles? I am not interested in monster power - fuel economy is king as this is my wife's daily driver.

Thanks as always - Josh

 

If the truck is running fine and not using or mixing any fluids I wouldn't worry about it myself.

Also I would never return to a 'mechanic' who installed a oil filter with a filter wrench. No, no, hand tight is plenty. Filter wrenches are for removal only.

 

I agree with the filter wrench... it was from the dealer I bought the vehicle from and the only reason i know he used a wrench is because there was a crease in the filter (that happened to leak oil after 1500 miles!).

What do yall think is a normal oil consumption rate? I am now closely monitoring the oil and want to gauge my consumption versus others. I am just worried because its my baby .

 

Normal oil consumption would be little to none imo.

I run t6 in my 7.3 and add maybe 1-2l between changes. Aprox 5000miles.

Mine will puff a bit of blue now and then, espescially after a long idle.

 

Typically you're looking for the opposite problem on a HEUI diesel: you want to make sure you aren't growing oil. Because of the direct injection system, fuel injector problems can cause fuel to wash down the cylinder walls and get past the rings into the crank case, causing fuel dilution of the oil.

You detect that by either having more oil come out than goes in, or by testing your used oil. Installing a Fumoto valve makes this an easy and mess-free process that you can do without dropping all the oil.

You can get used oil analysis from several vendors:
Used Oil Analysis - Bob is the Oil Guy - Bob is the Oil Guy
Blackstone Labs
Fram Advanced Engine Oil Analysis Kit SP9107A: Advance Auto Parts

Cat and Joh Deere dealers can also normally do this also:
John Deere Oilscan Oil Analysis Kit
Oil Analysis Lab and Oil Analyzers | Empire CAT