11TUXFX4

ISSUE:
Some 2011 F-150 vehicles equipped with a 5.0L engine and air conditioning (A/C) compressor stretchy belt configuration built on or before 2/14/2011 may exhibit a light lower end engine knock most noticeable when engine temperature is warm and the vehicle is at idle.

ACTION:
Refer to the Service Procedure to correct the condition.

SERVICE PROCEDURE

Remove the front end accessory drive (FEAD) and A/C compressor stretchy belt. Refer to Workshop Manual (WSM), Section 303-05 Removal and Installation Air Conditioning (A/C) compressor belt - 3.5L GTDI, 3.7L, 5.0L. Does the knocking noise remain?
Yes, the knocking noise remains after removing the A/C stretchy belt. Do not continue with this article. Refer to WSM, Section 303-00 for further diagnosis
No, the noise is no longer present. Obtain the Drive Belt Kit proceed to Step 2.
Remove the FEAD belt tensioner and bolt from the engine front cover. Refer to WSM, Section 303-05 - Exploded view.
Remove and discard existing A/C compressor to condenser discharge line and install new A/C compressor to condenser discharge line supplied in the Drive Belt Kit. Refer to WSM, Section 412-01.
Using a 8 X 1.25mm tap, clean the mounting locations noted on the engine front cover and use compressed shop air to clean any remaining debris. (Figure 1)


Figure 1 - Article 11-7-1


Install A/C compressor drive belt idler pulley and A/C compressor drive belt idler pulley bolt supplied in the drive belt kit onto the engine front cover top mounting location. Tighten to 25 N-m (18 lb-ft).
Install A/C drive compressor belt tensioner supplied in the drive belt kit onto the engine front cover lower mounting location. Tighten to 25 N-m 18 lb-ft).
Install new A/C compressor belt supplied in the drive belt kit. Refer to WSM, Section 303-05 R and A/C compressor belt - 3.5L GTDI, 3.7L, 5.0L referring to the 5.0L (4V) late build vehicles procedure for proper belt routing. (Figure 2)


Figure 2 - Article 11-7-1


Reinstall the FEAD belt tensioner and bolt onto the engine front cover. Tighten to 25 N-m(18 lb-ft). Refer to WSM, Section 303-05 FEAD - Exploded view 5.0L (4V) late build vehicles.
Reinstall the FEAD belt. Refer to WSM, Section 303-05 FEAD - Exploded view 5.0L (4V) late build vehicles.
Install Integrated Diagnostic System (IDS) and identify the vehicle. Answer the IDS screen prompts according to the current vehicle A/C belt configuration.
Reprogram the Powertrain Control Module (PCM) using IDS release 72.03 or later. This new calibration is not included in the VCM 2011.3 DVD. Calibration files may also be obtained at www.motorcraft.com.
Perform misfire monitor neutral profile correction. Select IDS toolbox icon, Powertrain, Service Functions, then Misfire Monitor Neutral Profile Correction.
NOTE: PLEASE ADVISE THE CUSTOMER THAT THIS VEHICLE IS EQUIPPED WITH AN ADAPTIVE TRANSMISSION SHIFT STRATEGY WHICH ALLOWS THE VEHICLE'S COMPUTER TO LEARN THE TRANSMISSION'S UNIQUE PARAMETERS AND IMPROVE SHIFT QUALITY. WHEN THE ADAPTIVE STRATEGY IS RESET, THE COMPUTER WILL BEGIN A RE-LEARNING PROCESS. THIS RE-LEARNING PROCESS MAY RESULT IN FIRMER THAN NORMAL UPSHIFTS AND DOWNSHIFTS FOR SEVERAL DAYS

ChampWJ

I think mine does this. Only noticed it a couple times but thought it was an odd sound. Good to know about this TSB, thanks.

bradseabridge

shoulda bought an EB... hahah

Stech

In reading the fix it says that if noise doesnt go away after removing the strechy belt refer to WSM, Section 303-00. What would that be.? I'm just about to pull the trigger on a new F150 screw 5.0 and definitely don't want to have to deal with a knocking sound. If the strechy belt doesnt fix it is there a fix or do some of these engines have a knock and I would have to live with it.?

Thanks

ny2az

thx for the update...will be bringing it in when its time for the oil change...

SpudLime

Is it me or does "stretchy belt" sound funny as an official name for a part? Haha

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Flabioso

Yup it sounds kinda stretchy to me...

mrnormal

Mine does this big time very noticeable at idle when warmed up. Bought it new two weeks ago with 12 miles on it and it had this low end knocking . Dealer tried a few things before I took delivery and signed on the line. They finally ended up removing the strechy belt and the low end knocking stopped now they are waiting on parts. Sounds just like a piston knocking around inside the bore, nasty at idle when it's warm you can hear it inside the cab if the windows are up and the radio is off. Glad to see a TSB out on this. My dealer had already ordered the parts kit last week they originally tried Ford Tech hotline and they said "noise normal" YA RIGHT 12 miles on it and that's normal. Then my dealer (rare great service dept. by the way) called and spoke to an engineer and he said there was an issue and that tech Hotline should have known about it. Anyway the noise does stop when the small A/C (strechy belt) is removed so hopefully the new tensioner and pulley/belt will eliminate it also... Some complaints over at Mustang 5.0 forums about this same issue also..

ChampWJ

Does anyone know how to find the official TSB number and information about this? Taking my truck in to the dealership tomorrow and hoping to have them explore this under warranty.

hillwood24

how loud exactly is knock? i know this is a stupid question, but i only buy new cars and usually only keep them like 1-1.5 years, so i've probably never heard such a thing.

i do know what knock is though, as i had a 2010 Mazdaspeed 3 and had to monitor knock with a device, but never actually had any.