SWHouston

James,

Those wet/dry numbers (on the low cylinders) are just too close to make me thing it's Rings, and I can't see it being a Gasket, not with that many lows and you not burning Coolant by the gallon.

As stated it's got to be an issue with the Valves or Cam.
If you can get hold of a Dial Micrometer, you could pull the plugs and Valve Covers, and check the lifts on the low compression Cylinders compared to the Higher Compression, then...

A Valve Job would resolve them and any Gasket issue.

At this point, I'm really thinking more toward Valves.

Ref: Leakdown Test

PS:
Yes, recheck the compression !

cookj

SW, i apologize. I've been refering to you as "CW" my last couple of posts; won't happen again. As for the pcm, although i don't quite remember what the mechanics indicated, they did say it wouldn't appear to be computer related, but, should i want to look into the programming of, i would need to take elsewhere.

cookj

SW, thanks for the info and link! I will check into it and get back. Probably the only thing i'll get an opportunity to do this weekend is recheck those cylinder pressures. Call it wishful thinking, but, maybe if it is valve related, it will be a simple of matter of adjusting, rather than a valve job. As for the head gaskets, I wasn't sure if there was a possibility of "leak by" between the cylinders, and not necessarily at the coolant jackets (if that makes any sense!). Will report back what i find. Thanks a bunch!

cookj

Didn't get much done today other than a recheck on the compression. I didn't have much time, so, just checked cylinders 2,4,6, and 8. Readings were pretty much identical to earlier ones (or, before using an entire can of seafoam).

one other thing I should note. I noticed the coolant level was a tad low, but, the overflow bottle was a little past the full mark.

At some point next week, will attempt to have a leakdown test performed and/or valves looked at as suggested by SW and others and report back. Time to enjoy the weekend, or, what's left of it. James

SWHouston

HA, no problem, I've been called worse. Most of my friends think I run CCW anyway.

Like I said before, I suspect Valves, and a Valve Job would be considerably less expensive than the Short Block cost.
(also would eliminate any Head Gasket issue)

This is a bit of a stretch, but...
As a last resort, you might consider a Performance Chip, just in case it's computer related.
(several threads here as to what type most like, and you can get one for <$100)

cookj

10-4 on the chip. Gonna call around today for pricing/availability of a leakdown tester and/or what a shop might charge to perform this work. Also, my son is coming by sometime today for us to replace his pads and front rotors on his '08 silverado so most likely no further work on the '99 today. To be continued...

cookj

Haven't done anything since i last posted and probably won't be able to till Wednesday or after. Kinda leaning towards just replacing with long block, or, buying some heads. Already have some prices on a new stock long block but was curious where might i find the cheapest set of heads. Can anyone help me out here? GM parts direct wants roughly $430 a head; kinda steep if you ask me. thanks!

MDTAHOE

This is who we order all our heads from at work.

Clearwater cylinder heads Home |

cookj

Thanks MD, will check them out.

cookj

After thinking about this over the weekend and through today, and, talking to a number of builders, believe i'm going to waive any further troubleshooting and drive it as is, or, at least until i have the funds to purchase a 350 longblock from GM. I even looked into a big block and the HT383 motors but cannot justify the added expense. For as clean and well-maintained this truck is in, it's frustrating to have these engine issues with only this many miles. I sure hope the new block i'll be purchasing will be more than capable of handling my towing needs, or, what very little i do; i know what i have under the hood now isn't.