heard a sound i never heard before today

when i am in park the engine is nice and quite

however when i put it in gear i have a knocking sound that i have never heard before

when i put it back in park all is quite

is this something that i just havent noticed before or do i have a problem

i did change oil about a week ago and i used a purlator fither from the cummins ok list and mobil delvac 1300 15-40 oil

what does a bad injector sound like

could this be what was happening

 

Here's an appropriate thread:
https://www.dieseltruckresource.com/...threadid=48641

titled: Engine Knock (with sound clip)

 

mitchkim:

I have (or had) the very same condition with my '04.
When in P or N was quiet. When I put it in D the knocking started.

What caught my attention on your post is that it started for you one week after changing the oil. I do not know if this means anything or not, but my knocking started one week after I changed my oil for the first time. I changed at 7000 miles. Used Valvoline Premium Blue, Fleetguard filters (oil and fuel).

I now have 8050 miles. About three weeks ago I started using Hammerdown #1500 fuel conditioner. Last night when I got home the knocking was gone. I'd like to think that the Hammerdown did the trick. Time will tell.

I have read some posts where the knocking appears and then goes away for a while. Others had an injector replaced. Some of the tech posts indicate that when we put our trucks in D this puts a load on the engine and the knocking sound is normal. Whatever the case, it seems to be something that many other CTD owners have.

Hope this helps, Ron

 

Try using BP Diesel. I was shown it was the specific gravity of the fuel is too light. The dealer here explained to me that BP is the only company that uses it's own source for diesel fuel, all others have the same source (around here) and just add their own additive package to the fuel. I tried the theory and it does seem to make a difference. I have a 6spd that does the same thing under low RPM loads. I just put up with it because the closest BP station to me that sells Diesel is WAY out of my way. 55 k miles on the clock as of yesterday and still chugs along just fine so it must not be too critical.

 

wonder if amoco diesel is the same as bp because i think they merged a while back