I have recently noticed an engine knock from 1800 rpm upwards, when pulling on a hill usually. If I ease off of the gas it will go away, when I rev the engine in park it sounds good no rattles or knocks. Is it possible that this could be a knock sensor going bad? I have an sai issue with the right-hand valve (p1415) could this be
connected with the fault?
Any ideas guys?

 

Don't want to scare you but this is the symptom that I had and everybody thought that I was hearing things! Did you oil light ever come ON on idle?
Get your oil pressure checked. My problem was the oil pump! Cracked in 5 places on the outer ring. It would only make the knocking/rattling noise under the load.
Don't mean to scare you or anything because I know this is not something anyone wants to hear and it could be other things as well. But in my case it was the oil pump.

Hope it's not the pump but have it looked at. Better safe than sorry.

 

Here's a pix of the pump with that kind of failure, can also cause the tick. CB, are you running somethingW40 oil? 30 weight too skinny.

 

My failure was the same as in the picture but I had more cracks!

 

I would say knock sensor but as already mentioned boris had this issue, have your oil pressure checked and then go from there.

 

Spike is right. I had this symptom on my failure but it could be something simple and not so serious.

 

Seems like there might be codes, but RAVE also mentions they can be loose as well. The knock sensors can make ECU retard timing to correct for wimpy gas.

 

Bad gas or improper octane gas (not saying your not using premuim) will do that. Check your oil pressure first, because if that goes, then you'll be up a brown creek without a paddle. Then burn through whatever gas you have left and try a different gas station.

 

Never trust someone else to fill up your truck....

 

So, stop drive it till you can have the oil pressure tested, stone cold at idle and 2000 RPM's and again when hot at idle and 2000 RPM's.
Get back to us with those 4 numbers.
It is not one of the knock sensors, you would have a code if it were.