P0306 ( cylinder #6 misfire) --> low compression.

[Opeth]

A flashing check engine light signifies something serious is going on either internally or emission wise, but a DTC code hasn't been figured out. Once the PCM figures out what is out of range, a DTC will set itself. A miss misfire every X revolutions will only cause the CEL to remain lit.

A constant misfire will cause the CEL to blink, meaning the cylinder is not firing at all and allowing too much raw fuel to enter the cat. It's advised to not run the engine if the CEL is flashing to prevent damage to the emission system. I tinkered for a week swapping coils and plugs and tightening the intake manifold bolts seeing if that solved the misfire. That Friday it went in since I didn't have the time or appropriate tools to dig further.

If those are the intervals of your DTC's then it's probably not as serious a mine was right now, but even so a misfire isn't something that should be let go for an extended period no matter what. You have a thread started on your misfire already don't you?

[bgwolfpack]

Flashing CEL? I'm not familiar with that operation of the CEL. I would guess it to be a more severe warning than a steady light.

I went through a stage where I got a steady CEL every few weeks, but lately I only get one every 4-6 months. Always P0302.

Have you ran a compression check yet James?

[Opeth]

Flashing CEL? I'm not familiar with that operation of the CEL. I would guess it to be a more severe warning than a steady light.

I went through a stage where I got a steady CEL every few weeks, but lately I only get one every 4-6 months. Always P0302.

Have you ran a compression check yet James?

He said he has the compression tester, just hasn't gotten to it just yet.

[Trail X]

Yeah, I keep pushing that down the list. But seeing your required repair has bumped it back up a bit more.

I just need to set aside a saturday to go down and really dig in there. The FSM has a good diagnostic routine worked out that includes stuff like checking injector resistances etc.

[dvanbramer88]

could they not just do a valve job with new gaskets and head bolts and put her back together?

GM states to replace the whole head if failure occurs versus repairing it. It probably can be done by a reputable machine shop with right equipment. A thorough cleaning, new guides, valves, machining the valve seats and decking the head might be the same cost as a new head in the end.

I saw a re-man. on ebay for $500 which could be an option as well. I'm not floating the bill on mine so I'm happy for a whole new head.

I did heads on my engine in 09. A reman head with valves already installed cost less than i could buy a set of valves for. It was a no brainier. I had burnt exhaust valves on cylinder #7 from a bad SFI unit. Remember this in non-TB. It's a 97 Chevy 350 Vortec. FWIW.