Loud knock?

[TRAMPLINEMAN]

My neighbor has an 04 CTD with 33,000 miles on it. Today, he came over and asked me to listen to it. At idle with the brake on, it has a very loud knock. Driving down the road it's fine. I suggested maybe bad fuel or maybe the valves needed to be adjusted. He brought it to the dealer and the service manager told him that 98. 5 to 05 24V's do not need to be adjusted until 100,000 miles. Now I know that 2nd gen 24's should be adjusted about every 15,000. Do the 3rd gens need to be adjusted every 15,000? Anyway, the serv. man. told him the #6 cylinder was gone. Amazing, he could tell just by looking at the truck without even opening the hood! We should get him on here. LOL Any suggestion or comments would be greatly appreciated!! Thanks, Mike

 

[Tomeygun]

My neighbor has an 04 CTD with 33,000 miles on it. Today, he came over and asked me to listen to it. At idle with the brake on, it has a very loud knock. Driving down the road it's fine. I suggested maybe bad fuel or maybe the valves needed to be adjusted. He brought it to the dealer and the service manager told him that 98. 5 to 05 24V's do not need to be adjusted until 100,000 miles. Now I know that 2nd gen 24's should be adjusted about every 15,000. Do the 3rd gens need to be adjusted every 15,000? Anyway, the serv. man. told him the #6 cylinder was gone. Amazing, he could tell just by looking at the truck without even opening the hood! We should get him on here. LOL Any suggestion or comments would be greatly appreciated!! Thanks, Mike

Thats talented! Looking at the engine, I dont know if there is anyway to know of a bum cylinder - Maybe a temp gun, and test for uneven temps... ????

 

[DPKetchum]

Never heard or read of a 24 valve 15k valve adjust by anyones repair or service manual. The manual says like every 125k or such. I don't remember. Of course you can adjust them when ever you want to. In diagnoising running propblems/missing/skipping etc. its one of the first things to do is verify valve clearance etc.

 

[nwjetboat]

Does it sound like this: Knock WAV file

Listen carefully, about halfway through the clip the truck is put into drive. That is the way my injector sounded. Clean at idle, but as soon as a load was placed on the engine, the knock showed up. Once you started driving, you couldn't hear it.



Here is the thread on the engine knock/injector replacement... Engine Knock Thread

 

[Rosco]

My truck had the same knock heard in the above sound clip. I had the #6 injector replaced and she was nice and quiet. However, lately it seems the knock may be returning (4,500 miles since the new injector was installed).

 

[TRAMPLINEMAN]

I was told the 15k adjustment by a couple different mech. 's. If this is not correct, I learned something new today, thanks! The clip sounded exactly the same as his truck. Thank you again, Mike.

 

[DPKetchum]

15k wasn't even on the old 12 valves. It was the first 24k and every 48k there after. Cummins has a site that list the valve adjust on the newer 24 valves. Its like at 124k or so hard usage and 150k lite usuage. Of couse as mentioned before you can check and adjust if needed at anytime if owner wanted to. I'll probaby check mine in the next year or so. I have 18k on it now. But if I do I won't think/worry about them for another 100k plus easily. In fact its in the owners manual/book if I'm not mistaken.

 

[TRAMPLINEMAN]

DP, thanks for the info, Mike.

 

[DPKetchum]

In diagnosing noise I would NOT over look going through the valve adjustment as part of check out etc.