Engine/Transmission (1998.5 - 2002) Knocking noise heard from under the engine?

[Intelman34]

*The truck info is in my signature*



This could be a perfectly normal sound, but I'd just like to run it past you guys anyway...



When idling, if I kneel down next to the front of the truck by the engine, I hear a real loud knocking sound. I can not hear it from above the truck even though it is so pronounced from under it.



What could this be?



Thanks and let me know.

 

[TomGolden]

Brandon, I don't mean to sound like I'm poking fun at you, but it may very well be the combustion "knock" and it is so pronounced when you're down low because the oil pan is soooo thin walled compared to the engine block and head, and so they muffle the knock much more than the oil pan does. When I duck my head down to a low level near my running engine, I absolutely hear what I am talking about, and so maybe it is also what you are hearing.



Tom

 

[Cowboy Medic]

I had noticed a similar sound in my truck last fall, I thought it was new cause I had never noticed it before. I watched everything real close, everything was in normal on the gauges, power seemed fine, didn't know what to think. Did a valve adjustment and noticed the knock was gone. Now this last week I am noticing it again and am wondering if I have to do another valve adjustment. The first one I did was at 95,000 miles I just passed 116,000 today. I thought the 24 valves weren't supposed to need the valve adjustments so often, but It is actually a very simple procedure so I think I will do it just to see if it goes away again.

 

[Intelman34]

Originally posted by TomGolden

Brandon, I don't mean to sound like I'm poking fun at you, but it may very well be the combustion "knock" and it is so pronounced when you're down low because the oil pan is soooo thin walled compared to the engine block and head, and so they muffle the knock much more than the oil pan does. When I duck my head down to a low level near my running engine, I absolutely hear what I am talking about, and so maybe it is also what you are hearing.



Tom

Tom,



Dont worry... i dont take anything the wrong way. I am new to diesels and i dont know anyone with a diesel so I am learning on my own.



Your theory makes perfect sense.



The truck only has 47,600 miles on it so hopefully it doesnt need a valve adjustment, but ya never know.



Thank you guys!

 

[Truckie]

Re enginr knock

I noticed a knocking at idle since I had the Edge EZ put on and the new boost elbow and removed the little plastic air thingie going from the fender to the air box. I removed the top to the air box and checked the filter and it was OK but once the top was off I could really here the noise and then I put my hand over the intake pipe to the turbo and the knock went away, removed my hand and it was back. I don't think it is any thing to worry bought I think it is just more air flowing through the filter and turbo.

MIKE