Tick,Tick,Tick..no more!!!
 

99 D2, Ticking after warm up, tried the usual oil/additive stuff..no luck.(have very good oil pressure) So I ordered in new rockers and shafts to install. Last weekend I pulled the upper intake and valve covers,this thing was clean inside! Even the lifter valley, no sludge at all! 1500000 miles. What a nice surprise. I knew the heads had been done at least once.
Installed the new rockers and shafts,prelubed everything,new gaskets etc. Started the engine, no ticking, but it ran awfull. Set codes 306/307 misfire. Had a heavy multi-cylinder miss. Crap!!!
After it was warm it was much better, but still missing at least on one. Took the upper intake back off and the valve covers and checked everything. I found two cylinders with 0 conpression ,3 cylinders with 45 and the rest with 150. Crap x 10!!! Removed the rocker shafts and checked leak down, all cylinders were very good and consistant... Put everything back together. At this point I felt the lifters were holding the valves open, to much lifter preload? Lifters gumed up on the inside?
Drove to work the next day to see if the lifters would loosen up and get better,still no ticking but still had a slight miss.
Today I pulled it apart again,and installed .010"shims between the heads and rocker shaft towers. This decreases the lifter preload by apx..026". Runs GREAT!!! No ticking no missing starts instantly.
I guess the point is,check the preload if you dont know how much has been removed from the heads. Make sure you compensate for changes in head gesket thickness and machining.....

Sweet, thanks for posting.

Is upper end ticking a common problem?

Yes it is on the DII.
So common its probably the number one complaint about the DII.

so a top-end tick that appears when things warm up in a 2003 is most likely what as a best guess?

Or is that a search for 'Tick' & 'Solved' answer;)

Could you please post a link to a shim and
or show us a picture of one?

That is quite a story you posted.

Very glad to hear the outcome was positive after removing the intake three times.

So let's review here - in this ticking problem the pre-load issue would happen only when the truck had already gone thru a HG repair with more metal removed by machine shop (there is a spec for max allowable - .02 inch), and the shims are a way to compensate for that. Good catch.

This thread was brought back from the dead...

Just so some people don't get the wrong idea about the ticks, you don't just throw shims in without first pulling and inspecting each lifter for wear and each cam lobe for flat spots, which can , especially at 150,000 miles be pretty normal because of our soft cams.
If there is an issue with the valve train, I suggest you read both of the stickys posted at the top of this section on how to inspect, measure and adjust for proper clearance.
A good practice is to always check your oil pressure, cold at idle and 2000 RPM's and again when hot, to make sure you don't have a warn or failing oil pump.

Hmm. this is a good idea. My engine ticked immediately after redoing my heads last year. I might have to check with the machine shop, and double check how much they took off, as the ticking doesn't sound like a typical bad lifter, and the engine was never overheated.