COLDHEART

I have a 98 24v built in nov.97.I understand some of these motors have adjustable valves and some don't.How do I find out which I have?

wannadiesel

All 5.9 liter Cummins engines have adjustable valves.

J BODY

Yes, they all have adjustable valves, but the 24 valve has a different set up than the old 12 valve that doesn't require as frequent of service like the 12'er.

thumper 549

pc of cake to adj.- lot of us gear heads run them at minum listed specs with good results

billg

If you have the 98.5 you have the 24v. The service manual says the valves should be adjusted at 150,000 miles. I have heard of people getting a little performance kick by doing it earlier. Also doing as thumper 549 says and running them close to the minimum spec because Cummins sends them out a little loose from the factory.
If you don’t already have one it would be a good idea to get you a service manual. You can get one here, it will be money well spent even if you don’t do the work yourself you will know how it should be done: https://techauthority.gltghosting.co...atalogId=10051
Hope this helps.

COLDHEART

thanx for the replies.I DO have a factory service manual for this year,but it only showed the 12 valve adjustment,that is why I even questioned it.I can do it myself,but with this much great knowledge available (dtr members)I figured I would ask.

COLDHEART

thank billg,I went there and ordered the 24v.supplement