I have a 2004 F150 Lariat with the 5.4L motor I bought used a couple months ago. I changed the oil last week with Motorcraft 5w20 blend like I have always used in my Wifes Exp, but I seem to remember the dealer I bought it from saying he had the oil changed before I bought it and put in synthetic. Should I have done a flush or something prior to using the blend?

Just the other day I got a bit of rough running at idle then it was gone. Then yesterday it did it again but the engine light came on and I pulled p0022 code. It has been running fine since and I forgot to get the code cleared when it was read so I don't know if it is still throwing a code even though it is running fine.

My question really is...could changing to the blend be causing the solinoid to start sticking? If so should I replace it and is it fairly easy?

 

It's not the oil.It doesn't hurt to swap from synthetic to conventional or vice versa. I'd keep running the Motorcraft 5w20 synthetic blend.

 

I was always told once you go to synthetic you should never go back to convetional, idk y but thats just what i was told.

 

That was true 20 years ago, but not now.

 

i was told....in older cars/cars with high miles, dont just suddenly switch to a synthetic because the synthetic is more likely to seep out of worn seals. May not have had a leak with conventional oil, but the synthetic will. Is this wrong??

 

I currently use full synthetic motorcraft but will be switching to the blended this next oil change.

Should not harm the engine and its not the oil that caused your problem. I would have the code cleared and see how she's running/or if still throwing the code.

 

You might want to consider some more maintenance also......
Like......
Cleaning the TB...
Cleaning the MAF...
Changing fuel filter...

All the above have procedures found in the how to forum....

 

Nowhere near what it used to be. I suppose it's possible, but not likely like it used to be. Both synthetics and conventionals aren't formulated like they used to be.

 

Well the light went out on it's own and I have not had anymore rough idle. Do you all think it was a fluke or should I be planning to replace the solenoid soon? In the searches for that code, there are usually other codes that come along with it, but mine was solo.

 

http://www.obd-codes.com/p0022