2004 F150 FX4 5.4...I have a rough idle and it surges at approx. 1100 RPMS,
like when in a parking lot. BUT, at 1100 RPMS while cruising I get a vibration
which basically mimicks the oscillation while moving "slow "at 1100 RPMS.. I cleaned throttle body and MAF, no difference. I have a K&N System, and am going to replace both Throttle body gaskets. It seem to have started when I pulled the PCV. I have checked PCV but it's not clogged..What else could be possible problem before I spend $$ at the dealer?

I appreciate any and all suggestions..
Thanks
Vaughn

 

check for vacuum leaks and clean the AIC.
have you run codes?

 

If this is 2004 3 valve (new body style) it doesn't have an idle air control. Check the Throttle Position Sensor, Clean the MAF and Throttle Body. IF it's still a problem then check with your dealer for an update to the ECM. Early 2004 3V had issues with algorithms used to run "throttle by wire" but a re-flash seems to help.

 

Where on new body styles is the TPS located?

 

Looking at the throttle body from the front..It's on the left hand side w/a large 3pin plug on the top

 

04 5.4....Rough idle, but is inconsistant. Sometime not bad, other times
worse..And vibration at 1100 and 1900 rpms UNDER LOAD.
The weird thing is that the problems lessen when I put air conditioner on.
I removed and cleaned throttle body, installed new gasket. Pulled Mass Air
Senser and cleaned. Problem continues...
Any ideas???

Thanks in advance..

 

Start with the basics; Fuel Filter and Plugs. COP's are the next best move. With a mid RPM mis, COP's are most likely the issues but the Fuel Filter and Plugs are cheaper starting point.

 

Hi,
The plugs and fuel filter were just replace 1 month ago..

 

COP's are next in line (i'd invest in the MC brand, the Ebay stuff is hit or MISS-lol) . What plugs did you use?? I was a big fan of the Champion one piece, but my first set died at 40K and my second set at less then 20K. I went back to MC brand I found a used plug extractor kit cheap. Check Rockauto for the COP's.

 

The dealer installed the plugs..So I guess they are whatever ford uses..

 

Have rough idle. 2004 5.4. Vibration at 1100 and 1900 rpms.Felt in steering wheel. The more engine is under load the worst...Mechanics said it runs fine. But never replicated problem. What the hell!
Have no idea what's going on..

 

Low grade misfire maybe? How many miles are on the truck? Have the spark plugs been changed?

 

MTM Ford is on the correct path. Start with the plugs (How many miles on them and what brand?) IF they are Motorcraft with less then 50K on them you're good, otherwise replace them. I thought I was smart and went to the Champion one piece. The first set lasted 40K miles the second only 22K. Now I'm back to the MC plugs and have been great for 50K+. The next move after the plugs is to clean the MAF sensor and throttle body, new fuel filter. After that comes the COP's, then move on to fuel injectors and check for a vacuum leak. If your plugs are up to date, my money is a failing COP'. (but the MAF, TB and FF need to be done)

 

Tell the mechanic to take a ride with you in the vehicle.

 

I have an engine vibration at 1100 and 1900 RPMS. Can feel it in steering wheel. It's NOT an out of balance wheel.
The more load on engine the worse. Like going up a hill in overdrive..
Dealer checked everything. PCM, vaccum, etc. and could not find a problem.
No codes. It is annoying the hell out of me. Other than the RPMs I mentioned ,it runs smooth. Although the idle is a little rough. I cleaned Throttle body, and MAF, with no change..It is a 2004 F150 5.4 engine.
Never had this problem before..

Any ideas would be appreciated...
Thanks..