2007 Denali wont start after cylinder head replacement

[Kraig]

If the battery was completely dead, it’s probably garbage. When you get your starter checked, get your battery checked too

 

[CAPT75]

I don’t have a voltage tester but I believe my neighbor does so I’ll see if I can get ahold of one. L When you had the same problem, did you also have any of the service/check engine lights/messages? I’m worried it may be a BCM/PCM issue only because I don’t get power to all my accessories (battery is fully charged) and the gear indicator light under PRND12 in the gauge cluster doesn’t illuminate either. I can shift into any of the gears, with the key in the on position, just no indicator light under which gear it’s in. The only other time I’ve seen it do that was when I was having issues with the MAF sensor, and it went into low power mode, but it never wouldn’t start.

 

[wjburken]

I did not have the warning lights as you describe. The BCM could very well be you issue but checking voltage at the starter is a cheap diagnostic step you can take. No voltage, it’s probably not your starter. If you have voltage, it warrants looking at the starter a little closer.

Once I got a good battery, the dash would light up like normal but when I turned the key to start, all I got was silence other than the relay for the starter clicking. I checked and was getting voltage to starter but no action. Took starter out and tested on bench in a vise with a set of jumper cables and still nothing. Took to Autozone and they said they confirmed it was dead.

I look back and laugh, but at the time I was going crazy. Imagine having everything but your block, pistons and crankshaft on tables in your garage to replace the camshaft and once you get everything put back together it doesn’t even turn over. First step in trouble shooting is look at what you just touched, which was basically everything! Once I went through and checked everything I could and confirmed with my brother-in-law, who helped, that everything we couldn’t easily check was done, I started chasing power.

Imagine my surprise, and eventual relief, when the starter, which had nothing to do what the vehicle was getting torn apart for, was the reason it would start. I thought for sure I jacked something up and was looking tearing things back apart.

 

[CAPT75]

Took the old starter to autozone to have it tested. I heard what sounded like spinning noise when they tested it, but they said it was bad. Got a new starter, put it in, exactly the same. No response from the starter, just silence and the relay clicking. Pretty sure the battery is garbage, had it on a trickle charger for a night and still barely got dash lights out of it. Jumped it off another truck and got all my dash lights, hvac fan, radio, but still no dashes illuminating under the gear indicator, can’t roll the windows up, power running boards don’t drop. The service engine light lights up but the obdII doesn’t read any codes. Traction control off, service stabilitrak, etc on the info center. I’m at a complete loss. I’m going to pull and check every single fuse in the truck to see if anything at all is bad. After that I have no ideas left!

 

[Doubeleive]

Took the old starter to autozone to have it tested. I heard what sounded like spinning noise when they tested it, but they said it was bad. Got a new starter, put it in, exactly the same. No response from the starter, just silence and the relay clicking. Pretty sure the battery is garbage, had it on a trickle charger for a night and still barely got dash lights out of it. Jumped it off another truck and got all my dash lights, hvac fan, radio, but still no dashes illuminating under the gear indicator, can’t roll the windows up, power running boards don’t drop. The service engine light lights up but the obdII doesn’t read any codes. Traction control off, service stabilitrak, etc on the info center. I’m at a complete loss. I’m going to pull and check every single fuse in the truck to see if anything at all is bad. After that I have no ideas left!

invest in a tech2 it will tell you all the little things that would be important right now, like is it sending a starter kill signal.
and just for fun, disconnect your battery then go turn the key to run/off a couple times, turn the light switch on/off a couple times, hit the brake pedal a couple times, then hook your battery back-up (preferably charged or new) and see if it will start then.

 

[CAPT75]

So it’s been a while, but I finally got the thing running. New battery, replaced all the relays in the starting circuit and reprogrammed the key. Although it’s still not without some issues. I’ve been driving it short distances periodically the last week or so. Still smells like burning oil, not sure if that’s the new gaskets or what. Figured excess spilt oil or other fluids that made a mess in the engine bay would’ve burnt off by now. My oil pressure is reading low for some reason, I’m maybe a quart low, but that shouldn’t be causing almost no oil pressure (that is if the gauge is accurate). Then a couple days ago the check engine light came back on and I noticed excess vibration coming and going while idling, like a shiver. Got the code read, and it’s a misfire on cylinder 5. Same cylinder that had the initial problem. It’s got new plugs and wires all around, I pulled the plug going to the coil as it was running and I still got spark arc’ing across, tells me the coil is good, and I compression tested it again and I have good compression in the cylinder. Not sure how to test the injector, but if it’s not the fuel injector, I’m not sure what else it could be? Especially since it’s only that cylinder. I thought maybe the gas could’ve gone bad since it sat for 8 months, but then wouldn’t that affect all the cylinders? If anyone has ideas, I’m all ears. Maybe something with the air/fuel mixture in the cylinder? I just want to get this thing running right so I can trade it in!

 

[Big Mama]

The fuel could certainly cause clogged injector. What was the code? There’s usually a little more info with a misfire code. Was the oil full or was it a quart low before the repair and was pressure low before too? If it was full how long did it take to lose a quart?

 

[CAPT75]

I never really knew what my oil pressure was before the repairs because my oil pressure sensing unit was bad, so I finally replaced that while I had the upper half of the engine torn down. I completely drained the oil and refilled it once it was reassembled. The code was a P0305, and there was another code I don’t remember off the top of my head. Something to do with the transmission fluid and low current. I’ll have to check my notes when I get back home, but if figured that a tranny code wouldn’t have anything to do with a cylinder specific misfire?

 

[CAPT75]

So I haven’t had a chance to get around to pulling the injector yet. I’ve been trying to at least run it for a few min each day to keep the battery charged and burn through the old fuel. I’m still above 3/4 of a tank. Oil pressure seems ok while I’m sitting there idling, a little below 40. I noticed when I start it, it runs smooth for about 30sec and then the misfire starts in. When I was installing the upper intake manifold, I accidently over torqued it. The specs called for an in/lbs torque wrench and I used a ft/lbs at the lowest setting because that’s all I had. As I was torquing it down, I heard the plastic pop. If something broke, or if the new gasket isn’t sealing right, that would cause a misfire correct? Throwing off the air/fuel mixture? I just figured if that was the case, it would affect more than just the one cylinder.

 

[bfourman]

Yes a cracked intake can cause a vacuum leak and a misfire.