Ford Power Stroke Nation banner

Running rough after oil change?

3K views 5 replies 3 participants last post by  393LX 
#1 ·
So here's my problem.....I recently changed oil in my '04 6.0L from the conventional Ford oil to Valvoline 5W-40 Extreme Blue. Right after this, I went on a trip, about 500 miles, and noticed that my fuel mileage dropped about 2 MPG with driving the same as I normally do, usually its very repeatable. The next morning I start my truck and it doesn't fire up as good either, and takes quite a bit longer to settle out. I get out and walk around to the passenger side and notice that my fender around the exhaust has black soot on it, never noticed it smoking but I guess you wouldn't on the highway.

Has anyone experienced this before? Is it possible I have a HPOP leak and the new synthetic oil made it worse? O-ring on injectors? Coincidence?

The truck has 97,000 miles, original everything including injectors, only mod is a 4" turbo back exhaust, which has been on there for about 6 months already. FICM was replaced under warranty 25,000 miles ago. Maybe my injector luck has finally ran out...
 
#2 ·
My WAG:

You probably have an ICP leak, it was there before but you never noticed it because it was so small, now that you have switched to 5W-40 SYN it has become more evident since the thinner oil can flow better, therefore causing you to lose ICP, the lack of ICP is causing poor atomization of the fuel giving you the black smoke on the fender, poor atomization will also hurt power since not all of the fuel is being burned, making the engine work harder and that can cause your 2 MPG drop

just my .02
 
#3 ·
Well if you still under warranty and your injector luck has ran out, at least it should be covered under warranty, i think anyways.
 
#4 ·
POWERSTROKER:

Thanks for the reply. I was kind of leaning towards there being a leak somewhere too. Does the ICP normally give trouble? Is it usually replaced all together or repaired with new seals?

Stroker67:

Unfortunately, its been off of warranty since Dec 08. Have had very little trouble with it up until now, I was hoping I got one of the good ones.
 
#5 ·
Is the truck hard to start when hot?

Has the check engine light came on at all?

Other than a little stumble in the morning, it seems to run fine?

Do you have a scanner?

You may have an ICP leak but its hard to say for sure with out further diagnosis. You could perform an air test, but you need a scanner to command the IPR closed or you will get false readings
 
#6 ·
Truck starts fine when hot and no check engine light. In the morning it cleans up for the most part after running for about 30 seconds and seems to run ok after that. Negative on the scanner, guess I'll have to book it in for service and see what they find.

Thanks again for the replies.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top