Uh.....Guys?

[accel]

He said this. "adding a tension arm to the A/C compressor to help even out the tension placed on the crankshaft".
This is absurd. If they have to account for some additional force from some belt they would need to balance crankshaft with that belt and A/C and pumps etc. connected to the crankshaft - which is not true.
When they used to provide vehicles with or without A/C some years ago they did not change crankshaft for the car they put A/C in.

Here's quote from Ford TSB that is in the beginning of the thread:

"Some 2011-2012 Mustang vehicles equipped with a 5.0L engine and air conditioning (A/C) compressor drive stretchy belt configuration may exhibit a light, lower-end engine knock most noticeable when engine temperature is warm and the vehicle is at idle."

So Ford itself acknowledges that the belt may cause "engine knock" (and not ac compressor or other accessory noise).

Honestly, if I install the tensioner and at least one flavor of engine ticks/knocks I have will go away - I'll be happy.

I'm not going to blame Condor if it will not work either.

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[Condor1970]

Here's quote from Ford TSB that is in the beginning of the thread:

"Some 2011-2012 Mustang vehicles equipped with a 5.0L engine and air conditioning (A/C) compressor drive stretchy belt configuration may exhibit a light, lower-end engine knock most noticeable when engine temperature is warm and the vehicle is at idle."

So Ford itself acknowledges that the belt may cause "engine knock" (and not ac compressor or other accessory noise).

Honestly, if I install the tensioner and at least one flavor of engine ticks/knocks I have will go away - I'll be happy.

I'm not going to blame Condor if it will not work either.

Thank you. I just want everyone who is seriously irked by this incessant tick to know that I did something, and it had what appears to be a positive affect. I'm certainly not setting in stone a course of action everyone should take. That would be irresponsible on my part.

If others want to try it with intention to achieve similar results, I see no reason why not. It certainly won't cause any harm that I can tell.

 

[GT Pony]

It's hard to tell. I would have to see the layout of the 11-14 compared to ours to see how everything is distributed. However, I would have to ask what causes more damage, adding a tensioner pulley and slightly changing the balance, or the lack of balance/increase of vibration that could be the cause of rattle in the stock layout.

If this kit bolts right up to the 11-14 and the 15-19 front cover and the belt is correct and the right length, then can't really be any significant differences.

 

[zackmd1]

I don't think he was stating it would be thrown out of balance. Auxiliary belts do have influence on angular forces on the crank and main bearing.

Exactly and there doesn't have to be a large force on the crank to change things just enough to cause some clearance issues. A small force in exactly the right location and direction could absolutely cause a slight misalignment.

Waiting to see others results before jumping in but certainly seems promising. My engine has also seemed to have slowed its consumption of oil just like many 350 owners have reported (decrease in oil consumption after 10k miles) so we shall see.

 

[Condor1970]

If this kit bolts right up to the 11-14 and the 15-19 front cover and the belt is correct and the right length, then can't really be any significant differences.

I think the 2018+ 5.0L engine uses the exact same front timing cover for all 5.0L vehicles. F-150's and Mustangs both. They are all made at the same factory and machined the exact same way on the same assembly line. Otherwise, why would the 2018+ Mustang GT have that same machining on the timing cover, if it only needed the stretchy belt? It's because it's the same cover for all the engines. From what I understand, the only difference in the Mustang GT, is the block PTWA liners, pistons, and DI system. That's about it. The timing covers are the same though.

If I'm totally wrong on that, please correct me.

 

[88lx50]

I think the 2018+ 5.0L engine uses the exact same front timing cover for all 5.0L vehicles. F-150's and Mustangs both. They are all made at the same factory and machined the exact same way on the same assembly line. Otherwise, why would the 2018+ Mustang GT have that same machining on the timing cover, if it only needed the stretchy belt? It's because it's the same cover for all the engines. From what I understand, the only difference in the Mustang GT, is the block PTWA liners, pistons, and DI system. That's about it. The timing covers are the same though.

If I'm totally wrong on that, please correct me.

The 2018+ F150 5.0 liter also has the PTWA liners and DI but less compression.

 

[Condor1970]

The 2018+ F150 5.0 liter also has the PTWA liners and DI but less compression.

Ahhh....didn't know that. Thanks.

 

[bootlegger]

He said this. "adding a tension arm to the A/C compressor to help even out the tension placed on the crankshaft".
This is absurd. If they have to account for some additional force from some belt they would need to balance crankshaft with that belt and A/C and pumps etc. connected to the crankshaft - which is not true.
When they used to provide vehicles with or without A/C some years ago they did not change crankshaft for the car they put A/C in.

Yet for decades we have known over tightening serpentine belts can accelerate main bearing failure.

 

[Kirgiz]

Yet for decades we have known over tightening serpentine belts can accelerate main bearing failure.

And you know it because you read article that is not related to the crankshaft bearings? These engines can produce 700 HP, withstand enormous forces and be balanced yet somehow adding pulley changes the operation of crankshaft. Moreover it changes it in this exactly precise direction seemed to be beneficial for engine. Be careful when you have to change A/C belt or A/C compressor when it breaks - you can disturb gentle equilibrium of crankshaft operations.

 

[bootlegger]

And you know it because you read article that is not related to the crankshaft bearings? These engines can produce 700 HP, withstand enormous forces and be balanced yet somehow adding pulley changes the operation of crankshaft. Moreover it changes it in this exactly precise direction seemed to be beneficial for engine. Be careful when you have to change A/C belt or A/C compressor when it breaks - you can disturb gentle equilibrium of crankshaft operations.

I guess you missed the TSB where Ford claimed the A/C stretchy belt was causing light knocking in the first gen Coyote. Main bearings are related to the crank, FYI.

 

[Kirgiz]

I guess you missed the TSB where Ford claimed the A/C stretchy belt was causing light knocking in the first gen Coyote. Main bearings are related to the crank, FYI.

Have you read it? Is there any mention of crankshaft or rod knock or piston slap? Have you noticed last steps?
Reprogram the Powertrain Control Module
Perform Misfire Monitor Neutral Profile Correction
Have you noticed they advise the same in TSB for F-150 - Reprogram the powertrain control module (PCM) using the latest software version of the appropriate Ford diagnostic scan tool.

 

[bootlegger]

Have you read it? Is there any mention of crankshaft or rod knock or piston slap? Have you noticed last steps?
Reprogram the Powertrain Control Module
Perform Misfire Monitor Neutral Profile Correction
Have you noticed they advise the same in TSB for F-150 - Reprogram the powertrain control module (PCM) using the latest software version of the appropriate Ford diagnostic scan tool.

Engine knock is a condition due to detonation. I never once said this was piston slap. I also never said the 2011 issue was exactly the same as the 2018. Only that the two could have similar causes. My only argument, is that unequal loads on the crank (via the serpentine belts), can cause internal issues. This is seen with shortened main bearing life due to overtightening of the belts.

As mentioned by others, the rattle in the Mustang has nothing to do with tuning, or it would be found in the datalogs. I am hesitant to believe a PCM change would fix the Mustang issues. I could be wrong, but I have also run stock and aftermarket fuel maps. My rattle was there either way. Only thing that changed it was turning off the A/C.

 

[barron64]

Not having a tensioner on the A/C belt drive and just using a "stretchy belt" is just plain lame engineering. Sure it saves weight, complexity and $$ but we live in reality and that belt WILL stretch over time. With that stretch, you are going to get some interesting vibration/harmonics on the slack side of the belt. The vibrating belt is going to create noise and vibration which will work on the A/C compressor and mounting bracket. Does this have any bearing on the tick? Who knows...As good as a guess as any at this point since Ford still is not saying anything.

 

[Kirgiz]

My only argument, is that unequal loads on the crank (via the serpentine belts), can cause internal issues. This is seen with shortened main bearing life due to overtightening of the belts.

And your only argument is invalid, as I stated before - they do not balance crankshafts with A/C and pump connected.
Load from serpentine belt is always unequal - they do not put several belts pulling crankshaft pulley from every side just to balance the belts pulling forces. What you refer as shortened main bearing life is from article about bearings found in industrial manufacturing, not about combustion engine crankshaft bearings.

 

[bootlegger]

And your only argument is invalid, as I stated before - they do not balance crankshafts with A/C and pump connected.
Load from serpentine belt is always unequal - they do not put several belts pulling crankshaft pulley from every side just to balance the belts pulling forces. What you refer as shortened main bearing life is from article about bearings found in industrial manufacturing, not about combustion engine crankshaft bearings.

You are missing some simple physics here. Excessive load or vibration in one direction on the crank will lead to more load and movement on the main bearings. The crank balance and main bearings have a certain tolerance for side loading. Exceed this tolerance, and you shorten the life of the bearings. The balance on a serpentine belt system doesn't mean having equal loads on all sides. In engine design, the key is to keep the load distributed as much as possible, and keeping the belts and pulleys balanced with the engine to reduce vibration. In the case of the mustang, I am not claiming the belts are only loading to one side causing the issue. However, something could throw the pulley system balance off, increasing vibration/movement on the crank pulley. It is clear, from the first gen, something was off balance enough to cause knock. Whether that is true in the 3rd gen remains to be seen.
There is also a factor of natural resonance with the system that could be playing here. It is hard to tell with the limited info Ford puts out.

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