streetsmoker

Well, went to replace what I diagnosed a few weeks ago as a bad injector today in cyl #5, and when the experts heard the truck crank up even before the replacement, they told me there was something mechanicaly wrong/broken to make it sound so bad but hoped injector was it. Replaced injector. Hard start, bad injector tick is gone now, but uncovered a worse problem.

#4 cyl is missing bad. Can hear the popping through exhaust, but more so through the intake pretty loudly. Disconnect the wires to injector seliniod #4 it changes idle tune/rpms but popping sound/missfire goes away. So what we looking at here??? I'm thinking/hoping beyond hope its just a loose valve seat causing the valve to not close properly or a chip in a valve.

MikeyB

With the history of the '03-04's dropping valve seats I would pull the head.
At least get that one issue taken care of.

MikeyB

Hounddog

Gotta pull head no matter what.Pull it and see.Same outcome eaither way.

elirandolph

is there a way to cure the 03-04 dropping seats? head rebuild with better seats?

MikeyB

Easiest way is by keeping the EGTs low as possible (1250 degrees max).
With the boost elbow and the latest SMARTY program I'm seeing about 950-1000 degrees max.

I believe they stake in the seats by pinging with a center punch to fix this issue.

MikeyB

streetsmoker

Ok, that was the majority opinion as to what is causing the problem. #4 exhaust valve lash was overly tight. Looked around on search and Seems #4 is usually a big culprit of dropped seats. But usually the ones who had problems had theirs drop and wound up with extremely loose valve lash.

So how much we talking bout for a complete rebuild with pinned seats on a rebuildable core??? I most likely will use Jeff Garmon, as he's the closest shop with a great reputation and service.

streetsmoker

Talked to a few shops. Several said I would be better all around starting off with a brand new '04.5+ loaded head which has the better intake ports and improved valve guides/seats. So, looks like I'll be going this route. Anybody have one laying around they dont need?

Hounddog

Do a webb search on Dover Cylinder heads.Call and ask them about seats and such.The one in Atlanta was run by a tech that worked for me years ago.I've bought several sets of heads from them over the years.First rate high tech head shop.