Ticking sound on a c15 acert

Now that it seems intermittent, that would be my guess also.

 

Some good advice there with the home made stethoscopes . With the noise not there from cold. It could be Iva related when it warms up.
Let us know what they find.

 

I have a hole fleet of mxs acerts. Some of them make that metalic noise some don't. It sounds like a rod knock but not that loud. I can't find out what it is. I called the east coast rep about this and he said it is the torsional load from the injectors ringing up though the cam into the gearset. Does the noise sound like it is in front of motor? I have pulled the oil pan down changed rod bearings main bearings,and pulled rocker arms off checked rollers and every thing and noise is still there. It drives me nuts because the noise sounds like a ping ping ping ping almost like rod knock but it is not and the noise is hard to pin point because it carrys. Just some input because I would sure like to know what it is.

 

Retract exhaust valve thought if it sounds solid I guess is the word. If some do some don't, they seem to last a while with this noise I'm with morehp on the IVA housing. Noises are so hard to describe.

 

Mine do it cold or hot don't matter.

 

I had something like this. Ended up the #3 exhaust valve adjustment bolt had backed off all the way and thankfully went down to the pan, not taking anything else with it. If you notice a bit of a miss on your jake's it's probably a exhaust valve. I didn't notice my miss was as bad as it was until I put straight pipes on my truck, I would guess that problem had been there for a year or so at least. My engine is a 5EK Cat but the principals the same. This would also make sense to me as you said someone ran the rack 50k ago. Mistakes and accidents happen, maybe they didn't get one nut tightened down all the way.

 

Any time you have a noise, and are doing a set, you want to look at all the valve and injector springs, on any engine, cam followers and you have to feel the cam the back cylinders are hard to see in a lot of units. You also want to remove the belts, I have seen an alternator that had a bad bearing cause the engine to be taken apart, When they gave it to me and I put a bar on the different components and was taking off the belts, I was told they were sure it was a piston problem. When I came in and asked the customer if he had replaced the alternator recently and had the bill amazingly everyone that had all the advice, had things to do and were gone. A broken cage on a bearing will create noises that migrate a long way. I had a friend all ready to tear apart a 400 pontiac because it had a knock, we both were sure it was #5, the belts were old so I just cut them and had him start it no more noise.
On every job you really do have to start with the basics, that is one of the hardest thing you need to remind yourself.
Just a thought

 

http://www.amazon.com/Steelman-STE65001-Engine-Electronic-Stethoscope/dp/B000WNJ90W

 

When I had my dilemma in my post above we ran the whole overhead just cause I was already in there. Other than the #3 exhaust (obviously) everything was fairly in adjustment. On my last IFTA quarter that truck came up .20 or so of a mile per gallon. But that could entirely be a number of other things, most noteably not having as many jobs on hillside subdivisions, and the ones I was on was mostly going up empty and hauling clay off loaded. In my instance the 2 things I noticed were my jake brake works a noticeable bit better, sometimes a split gear on my 18 speed better, and the motor runs much smoother, doesn't sound like a bunch of pissed off bees buzzing, more of a smooth bumble.

Basically I'm trying to say what you've got going on is normal for the circumstances.