Why does our cummins have a compression squeak when we turn it off and the powerstroke 6.0 litres and duramaxes dont. is it because they have 8 smaller pistons? Does any1 know what im talking about?when we turn our trucks off you canhear what sounds like a 2 second squeak.does the 5.9 have a higher compression than the powerjoke?

 

it's because of the high compression of the cylinders stops the engine fairly quickly while the accesories don't stop as quickly that's why there's a squeak.

 

ok makes sense

 

Because of this compression pressure building up and equalizing duing engine shut-down, your crankshaft will actually oscillate a few degrees... imagine the power of the crankshaft pulley shifting rapidly CW and CCW for just a split second, the accessory drive belt sometimes can't drive the accessories back and fourth and will slip the belt creating the squeak.... this is normal operation.

 

I noticed that too. Glad to hear it's normal.

 

BTW. . .this only exists for auto's. the flex plate is not as heavy as the flywheel. the flywheel keeps the engine turning just a little more.

 

Mine don't 'squeak' - - it giggles at the 'wanna be's'around me

 

I replaced the idler pulley and its gone for the most part. I just took it for granted that it was there before and that most CTDs did it.

 

Mine only 'chirps' whenI turn it off with the AC running.. tested this many times in hot and colder weather.. no AC .. no chirp

 

Mine only does it when I had the air running or it is hot out.It's hard to stop all those horses on a dime.