redramnc

Since my truck turned 200K I decided it needed a full fluid change and to chase down some oozing fluids in various places. Since I was planning on changing the valve cover gaskets I decided to run the valves. When I got the truck used I waited until just over 100K miles to do the valves and found only 2 or 3 that reqired minor adjustment then. Since then I have not heard any tickings I could assign to the valvetrain so I have left well enough alone until the other day. Checked them all and did not find any that required adjusting. Some side to side movement on the feeler gauge but no up and down click to be felt. I have always heard that after the first time you adjust them they stay pretty good after that. Just wondering if this sounds normal.

This truck is pretty stock (trying to save the tranny as long as possible) and sees the road 27 miles each way to work at 65-70 so it doesn't lead a hard life.

Geico266

Sounds normal. When I checked mine at 150K there were none out of adjustment.

crobtex

While we're on the subject....................

What are the signs of needing the valves adjusted?

Forrest Nearing

you can slide a thicker feeler gauge in there than you're supposed to be able to

MikeR

They're not out by 100k????

Every 24v I've tounched have been out by 50k. And both my 12v's have been out too.

infidel

I've found that after 100k adjusting the valves on a 12 valve is a usually waste of time.
The adjustment schedule should read like this 24k, 48k, and every 100k thereafter.
If I find the #1 valves don't need adjusting I don't even bother removing the rest of the covers.

rentalguy

Valves clearances getting loose is easy,youll often hear them ticking.
But what about when the valve starts pounding into the seat and the clearance gets too small?Youll never know the gap is closing until its too late and the cylinder stops firing and you possibly burn a valve.
Ive had it happen several times on various rental tractors,mostly Yanmar engines.Im not sure how tuff the Cummins valves and seats are against this type of thing but,personally,if Im gonna pop one valve cover, I do them all.....call me cautious.

redramnc

I have never heard of Cummins valves going tight - but there is always a first time, I reckon. Having cut my valve adjusting teeth on modified SBCs and farm equipment it seems a little strange to me that 100K miles (1667 engine hours @ 60mph) would not cause some wear to be evident in the valvetrain. That said, I have always heard basically what Bill said - once the valves are set properly and broke in good they do not tend to need attention unless something obvious goes wrong. This is just the first time I have run across it myself - now I know not to be surprised if I see it again.

As a comparison, I have wiped cam lobes on 2 IH 345 motors at or before 205K miles - and those motors are some of the toughest hunks of slow-revving iron to be found. Of course, both of those were cam failures, not block/crank/piston failures, so I reckon they can still be considered formidable motors, if not very fast. But I still like my CTD better.........

Now if I could only convince my wife that a 6BT needs to replace the SD-220 in the 53 R-112