I bought a 2004 5.4 3v heritage. The problem that I'm having is when cold start the truck it runs great, but when the temp gauge reaches the first line (I'm assuming 160) it's goes into a rough idle for a few minutes and stalls. I'm new the the ford community and have no idea what I'm doing. Thanks for any help

 

CE codes?

When a vehicle starts, it is in open loop mode which is a preprogrammed mode. When the engine warms and the O2 sensors start working it goes into closed loop mode where the computer controls engine fuel enrichment. It sounds like when yours goes into closed loop mode, it doesn't work properly. Some of the real mechanics will chime in soon and tell you how to troubleshoot it.

 

What do you have? The 04 Heritage didn't have a 5.4 3 valve.

 

I was told it was the heritage. In 2004 they had two different body styles

 

The VIN number is definitive. Get your VIN and look it up in a reliable VIN decoder. If you post the first 10 or 12 digits here, we can also tell you what it is. It's not necessary to post the last string of numbers here.

In 2004, they had a mix of the "Heritage" which were holdovers from the 2003 MY (OBS) and the 2004 NBS. This overlap was created because Ford kept one of their F150 factories cranking out the old body style (OBS) while the other was converted over to the new body style (NBS). Once the conversion was completed at the factory producing the NBS, Ford went back and converted the factory that was still cranking out the leftover Heritage models.

 

On the vin lookup all it tells me is 5.4l v8 300hp 365fttq

 

That is not a Heritage, it's new body style.

 

So this weekend I pulled the throttle body off and scrubbed it pretty good and also cleaned the mass air sensor that seemed to help tremendously. But still not perfect. Well I poking around online and a few people said to replace the pcv valve. I went to AutoZone and they told me it's a non serviceable part , that I have to replace the whole Damn valve cover! Is this true?

 

Of course not, it's Autozone.

Go to your Ford Dealer (or shop online) with your complete VIN (!!!!) and buy the complete PCV hose assembly which includes the valve.

 

Hope you haven't figured this out the hard way already by now --- but your Autozone guy was 'partly right'. It's not a serviceable part, because the 5.4 3v does not have a 'PCV valve' at all. Filtered air from your passenger side of the air box is drawn into the Bank 1 v/c, through the crankcase, and into the IM through the drivers side v/c tube - which has a heater element in the IM end of the tube. The heater comes on, I think, below about 40 degrees (ambient).


EDIT:
I reviewed prior posts to see what symptom might have lead you to want to change PCV valve (if other than just maintenance) but I didn't see anything.


Couple more thoughts that escape many of us old timers who have sat at a red light and watched a cloud of blow by pour out from under the grill, wheel wells, and cracks around the hood on the old car in front of us.
On the 5.4L, the crankcase ventilation 'source' air from the filter box is already 'filtered' AND 'metered', and it is presumed 'blow by' has the oxygen burned, so its direct ingestion into the intake manifold from the Bank 2 valve cover does not upset stoichiometric AFR seen by the O2 sensor - and avoids contaminating the air filter. There's never any positive pressure in the crankcase - thus no need for the PCV valve.


I agree with @Roadie - I would like to know if the symptom coincides with the PCM going into 'closed loop'. That can be observed via the OBDII system if you have a reader capable of reading live data (PID #1103, bit #6).

 

I'm seeing conflicting information - seems the 04 5.4 3V may have a PCV valve, 05 and newer definitely does not. It's just a fixed orifice within the valve cover.

 

@glc, mine is an '04 Lariat and it doesn't. It is configured as described. Not sure which plant it was built in, but I bought it new in early (March) 2004. I struggled with the same issue in my efforts to find/isolate the annoying 'random misfire'. Went through the 'unbelievable trouble' of removing the PS reservoir bracket trying to get to what I thought was a PCV valve and damn near tore up the valve cover before figuring out the crank ventilation system is a 'negative pressure' system instead of positive pressure one! Anyhow, there may be a mixture of them out there, but was hoping to save @Matthew Mead from my struggles finding it out.