Chevy & GMC Vans

MY 246k '98 still runs fantastic and serves multiple purposes for our family. I've been chasing a poor idle for awhile and finally gave up and took it to a mechanic I trust. He ran diagnostics, then a compression test. #4 cylinder is low, valves are bad.
I checked machine cost in the SoCal area, $300/pair. Gasket set is about $100. I guess I'll tackle this; unbolt, have machined, bolt back on. Anything more I should know?

LaGrasta wrote: ↑Thu Jul 28, 2022 3:16 pm#4 cylinder is low, valves are bad.

if one cylinder is going out, then ....
how many miles on it?

LaGrasta wrote: ↑Thu Jul 28, 2022 3:16 pm$300/pair

per pair of what ... valves? You're not going to do just one cylinder are you?

LaGrasta wrote: ↑Thu Jul 28, 2022 3:16 pmGasket set is about $100.

you're talking about a top end rebuild + kit + machining. To the restore just the top end you could be looking at thousands of $ .... On an old engine block that may be on its way out ...
I would have a serious think about it.

For $300, the machine shop will rebuild both heads. The heads/engine/van have 246k.

well that's a reasonable price.
But I'm suspicious about why the valves would be bad. And how's the rest of the engine ... piston rings, crank bearings etc. ... and the transmission...

everything else is 100%, runs fantastic and is super dependable.

I may run some valve cleaner through it on a long drive, maybe that will be enough.

We sold it to a Texas couple that doesn't have to smog it, $5800. They drove straight from our SoCal home to Las Vegas, then up to Colorado! We're gonna miss that one! We owned it since new, October of 1997.

Well you had a good run. Are you replacing it?

No plans for replacement. Although I already have a few needs for a van, lol.

:-k Sorry to revive an old Thread, but King's Auto Repair (Oakley, CA, USA) identified the cause for (a) PCM-perceived miss at idle and (b) high NOx indicating lean-out at 15 and 25 MPH per CARB dyno test: Leaky valve(s), #5 cylinder. King's no longer has the resources to fix the leak(s). The Vortec 4300 CSFI requires dismounting to accomplish the valve job anyways, so a double full head rebuild comes into the question.

So I gotta ask: With the pre-existing cab door latch problems and the compromised helper-door window motor, plus the HVAC control breakage and windshield-washer nozzle failures, is the cumulative repair price more than the potential value upon restoration?