I would appreciate some advice/help. 2000 F150 5.4LTriton "L" engine. Truck was running fine and then I heard a 'Dink' sound, didn't think much of it until it started shuddering. No ses, cel, or any other dash lights came on. Got home and put the scan tool on it and got P0308 and P0113. Misfire #8 cyl, and IAT sensor.

How can I test the IAT sensor, and are the spark plugs really that much of a MF'r to change? I'm going to go check the readings again right now.

Truck has 84K miles.

 

Plugs are reasonably easy to change, but you may need to lift the fuel rail. It's the 2004-2008 3 valve plugs that stick and break. However, there are only 4 threads in the head, so they will loosen and blow out if not torqued to 28 ft/lb. I'd change them all if they are original, use Motorcraft plugs.

Now, I see conflicting info. Some say that the IAT is integrated into the MAF, others say it's separate. Best thing to do first is make sure it hasn't fallen out of the intake tube, and pull, clean, and reseat the connector. I believe it can be tested with an ohmmeter if it's separate.

 

Well the codes are still the same. What can I use to safely clean the IAT, and how do I go about testing the sensor? Is there a diagram somewhere?

 

There's no point in cleaning an IAT sensor, It's just a thermistor. It is separate from the MAF on your engine.

You'd better check #8 for a blown plug. If okay, do a compression test. Electronic issues don't go "Dink" but mechanical stuff sure can when it breaks.

 

Can I test the IAT, or should I just replace it? Changing the plug(s) is going to be tough for me due to my size(round), but I'll see who I can find to take care of that. Truck will not be going anywhere until it's fixed.

 

I believe I said it can be tested with an ohmmeter, resistance varies with temperature. I do not know the proper value. Obviously if it reads almost zero ohms or infinity, it's bad.. If it's separate, it is right near the MAF. This video shows how to change it:


If you have a blown plug, you will probably need a Timesert or Lock N Stitch. Do not use a helicoil, they will not last.

 

The spark plugs are hard to get to but you can change them. I spent quite a few hours taking my time changing mine. As I remember, I didn't need any special tools but I did have to pull the driver's side fuel rail which was easy to do. Since the heads only have 4 or 5 threads holding the plugs, torque them to 28 ft lbs, not 12 ft lbs that the manual says to keep them from blowing out. At the time, about 2011, the dealers were charging $220 or more labor to change the plugs plus $10 per plug.

 

Can someone clarify if I have the 2 or 3 valve per cylinder engine? And what is the primary issue with the plugs in the "L" engine that I have? Should I replace the COP's since I'm in there? That would be $300 worth of parts that I may not need, but if they're prone to failure I'd rather not have to go through the whole process again.

Thanks for all the help everyone!

 

You have a 2 valve. The 3 valve wasn't introduced till 2004. The primary issue is blowout, as I have already described.

Replace the cops if it still misses, they are pretty easy to change. They are only prone to failure if you run it for any period of time with it missing or with excessive plug gaps, or if you wash the engine. If you do replace them, use Motorcraft, Denso, or Delphi. As I already said, use Motorcraft plugs and torque them to 28 ft/lb.

 

I failed to mentioned that I did wash the underside of my hood shortly before the issue started. I should have been much more careful.

 

You can swap cop #8 with another cylinder, clear the codes, and see what comes back. If the miss changes cylinders, it's a bad cop. At 84k, if those plugs are original, change them.

 

Pay attention to the code description!
Code 113 is an open circuit.
Connector is either not seated or the harness is open at some point.
The computer checks for current through the resistance. If none detected, it's a coded for 'high' or open circuit.
Don't just fly with the word IAT and ignore the rest.

 

I appreciate all the info. Thank You!

Will report back my findings.

 

Long Update:
I apologize for the delay, but we've had nothing but heat and humidity the past 2 weeks, and the lack of any shade in my apartment complex, and I'm not in the best physical shape to be doing this stuff anymore.

Day 1: Changed plugs/coils on cyl 5-8, worst part was getting covered with soot from an intake manifold vacuum hose (which will be getting replaced). I had to borrow a portable air tank with a blow gun as I have no access to an air compressor to get as much debris as I could away from the work area.

Day 2: I finished up cyl 1-4 and the only problem I had was that I had taped the spark plug socket to an extension and when I realized that I needed a 6" extension and when I pulled on the socket on the #4 cyl it separated from the extension it was taped to. Now I had a new problem, and I called it a day.

Day 3: Was able to grab the spark plug socket with 6" needle nosed pliers and breathed a sigh of relief when it came out. Most of the problem on cyl #4 was caused by not having a stubby ratchet. It is a very tight area to try and work in.

Day 4: Buttoned everything up and went for a test drive of 100 miles and all went well.

This is a job that can be done in a day provided you have all the parts needed, and the necessary tools at hand(I didn't), good weather, and a good mindset, and patience. I did not have to lift the fuel rail, and I didn't have any stripped out spark plug threads. All new plugs were torqued to 28.5 ft lbs.

I would definitely have a 3/8 stubby ratchet available.

 

I realize it is a little late to post this but for future reference.... I don't know about the 5.4 heads but on the 4.6 the plugs blow out easily. Never change the plugs with the engine hot. It will weaken what few threads are in the head. It may not blow out immediately, but once those threads are weakened its not the matter of if they will blow out, it's when!
Hey you other guys on here, do the 5.4's do the same thing?