engine knock

hernando · Mar 10, 2012

i have a older gas john deere in has a knock in the engine i thought it was a rod but i was told it was carbon build up...how do you tell the difference between the two ? it does not make the knocking sound when under a load....using the loader ect....but when just driving it across a field it starts knocking...... any ideas ??? i dont want to do a rebuild unless i have too...thanks for the help bruce

rsewill · Mar 10, 2012

There was a recent post by someone who used Seafoam for carbon.

hernando · Mar 11, 2012

ok thanks i will check on that bruce

Ford tractor · Mar 12, 2012

You can also feed in a gallon of water (in a metered slow fashion!) to a hot engine and it will clean off the carbon. I use a small diameter hose to a vacuum port. Keep rpms to PTO levels. It will cool the engine so you need to keep a watch on temperatures to keep the engine hot. It works better when hot.

hernando · Mar 18, 2012

changed the timing ....it helped alot.. thanks for the help bruce

Jerry/MT · Mar 18, 2012

hernando said:
i have a older gas john deere in has a knock in the engine i thought it was a rod but i was told it was carbon build up...how do you tell the difference between the two ? it does not make the knocking sound when under a load....using the loader ect....but when just driving it across a field it starts knocking...... any ideas ??? i dont want to do a rebuild unless i have too...thanks for the help bruce

Check the intial timing and the advance function.