1997 K1500 5.7, new cylinder heads and gaskets, started and ran for a short while now wont start at all

[seant117]

Hello, I have a 1997 K1500 5.7 Vortec.

About a month ago, I was driving my truck and it was running beautifully. The engine was smooth, the transmission was shifting nice and the AC was blowing ice cold. It was a great day.

I was driving down a road when suddenly I felt like the engine was running a little rougher than usual. At the next red light, the whole truck was shaking and misfiring pretty bad. I managed to get it home safely. I waited a few moments to try to start it up and it barely started, but this time with white smoke coming out of the tailpipe. I shut it off pretty quick and dove into it.

Pulled spark plugs, number 4 cylinder was wet. Oh no. I decided to do a compression test on bank 2. Cylinders 2, 6 and 8 all read right around 145 PSI. Cylinder 4 read right around 30

I stuck a camera down cylinder 4 to find a puddle of coolant and a bunch of carbon deposits broken up on the piston head. Well, that's one way to clean carbon deposits I guess...

I determined I have a bad head gasket. Plus the truck is 26 years old, it definitely won't hurt to put a fresh set of head gaskets on there so I won't have issues in the future.

I tore the engine down, labeled all the bolts in bags, kept everything in order. Got the cylinder heads off, upon visual inspection, the heads looked good. No cracks that I can see.

I looked at the cylinder walls. Factory cross hatching , nice and smooth to the touch on all cylinders. Nothing odd to report.

I get scraping the old graphite head gasket material off. I worked on it for hours trying to get a nice smooth mating surface.

I decided to splurge and get a pair of new cylinder heads from Clearwater Cylinder Head. They came in a couple weeks and looked great! The ones that came off my truck are 062's, the ones I purchased were 906's. From what I read, there's practically no difference.

While waiting for the new cylinder heads, I decide this would be a good time to replace the leaking oil cooler lines and housing gaskets. That was a messy job.

I then gave the engine block one last wipe down and a visual inspection. Blew out all the dust, made sure both mating surfaces were spotless and smooth. I squirted a little assembly lube into the cylinders. I installed the heads, used ARP head bolts and put some thread sealer on the threads and torqued everything to spec in the correct order.

After getting the heads on, I installed all the push rods and rockers in the order they came out.

I reassembled the engine and all the accessories, got new intake manifold gaskets, used RTV to seal the manifold to the engine block, replaced the O rings for the fuel lines to the fuel injectors.

While installing the distributor, I noticed that I couldn't get the rotor to line up with TDC, distributor wasn't sitting all the way in. Weird. I look at the distributor, I look at that might be interfering. Oil pump. Nice. I stuck a flat blade screwdriver down there and rotated the oil pump shaft til the distributor can be installed all the way in and rotate smoothly. I spun the crank shaft a few times to make sure everything is lined up.

I decided to take this opportunity to upgrade from the 5 blade metal fan to the 11 blade plastic fan. I'm hoping my truck can feel some of my love towards it.

I let the truck sit for about 24 or more hours after that for all the RTV and sealer to dry.

After waiting, I filled up the cooling system with coolant and changed the engine oil and filter.

Hooked the battery back up. Moment of truth.

I put the key into the ignition and the truck started up on the second crank and ran! I was so happy. No more lumpy running. I got out, white smoke coming out of the tailpipe. Okay, maybe it's burning off the assembly lube. We'll let that sit while the coolant bleeds.

It's been about 20 minutes, still smoking from the tailpipe. Hm. Okay, maybe I'll just take it for a light drive around the neighborhood. It's a little lumpy. My first thought was maybe I didn't adjust the valves correctly, but the good thing is I don't hear any ticking.

I'm driving around for about 10 minutes and it seems like its starting to run a little worst. I'm pretty worried now. It's definitely not as bad as it was before when this issue first arose. No more smoke coming out of the tailpipe.

I get it back home, and the "Check Gauges" light comes on, very low oil pressure. When I first started it earlier, it was sitting a couple ticks about 40 PSI, plug it's a new GM Genuine oil pressure sending unit that's been in there for a couple months. I shut the truck off right away.

I let it sit for a few minutes, had a beer, a little annoyed then went out to try to start it. It'll crank and crank, but won't kick on.

Plugged in a code reader. I didn't clear the codes from before, so it's still showing Cylinder 4 misfire, and I hope that's not a new code, P1351 Ignition Coil Output High, Pulse Detected Cylinder 1, P0155, O2 Sensor Heater Circuit Bank 2 Sensor 1, P0300, Random Multiple Misfires detected. Huh.

My question is... what could this be? I did everything by the book as far as I can tell, took my time and make sure I didn't shortcut anything, didn't even end up with a single extra bolt or part, didn't go cheap on any part, gave it some nice love and now this? I haven't done a compression test on it yet or any troubleshooting. To be honest, I was pretty frustrated and went out for a few beers with a friend and now I'm here.

I would appreciate any tips or tricks. Thanks!

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[Schurkey]

1. Clear the codes, see what comes back.

2. "Codes" are the BEGINNING of computer diagnosis. The data stream tells all.

3. Consider another cranking compression test. If the pressures are low or inconsistent, I'd be re-doing the rocker-arm lifter preload adjustment. LOTS of folks get that too tight. Finding "zero lash" seems to be the stumbling block.

 

[seant117]

Hello, thanks for the reply. I went ahead and readjusted the valves today. Boy it's a PITA to get that drivers valve cover off compared to the passenger side. I loosened up every valve and went by the GM service manual to adjust the valves. Got the truck back together, it started and ran, much smoother than before. However, still misfiring and on the same cylinder I was initially having an issue with. I'm feeling pretty defeated. New head gaskets, new cylinder heads, ARP head bolts torqued to spec, everything is in time. Unburned fuel smoking out of the tail pipe. The great thing is no tailgaters, bad thing is I have a massive headache. What else would be causing this issue? Maybe a bad lifter? Thew weird thing is this issue happened suddenly out of nowhere, so something had to have broken suddenly for it to start to misfire like this.

 

[Schurkey]

readjusted the valves today... ...it started and ran, much smoother than before.

Progress.

still misfiring and on the same cylinder I was initially having an issue with.

Fouled plug?

[Edit] Cranking compression test of at least the problem cylinder?[/Edit]

Unburned fuel smoking out of the tail pipe.

No catalyst?

 

[Erik the Awful]

What else would be causing this issue?

I'd guess a bad lifter or a bad cam lobe.

With the engine cool, take off your radiator cap, start it up, and once the engine warms up, check to see if you have combustion gases burping up out of the radiator neck. That will tell you if you have a cracked block. My Suburban's 350 looked fine when I threw it together, but the block was cracked.

 

[texas tough]

white smoke is steam.. did you inspect the block for crack or warping? I like to put a straight edge across the block at different angles. you can pull the head on the side that is leaking coolant into the block, clean the mating surface and put some rags in the cylinders,., if u cant see any obvious defects on the surface of the block, take some very fine baby powder and sprinkle it on the top of the block,, this is the old school method before magnaflux.. if there is a crack, you will see it.. best use for babypowder besides butt cracks..,. haha
If the block is slightly warped, u may be able to true it up with a ******* file and alot of elbow grease.. then maybe use a slightly thicker head gasket. u might lose a little compression but it is better than pulling the motor.

 

[Schurkey]

white smoke is steam.

Or burning ATF. But modern automatic transmissions don't have a vacuum modulator, so no ATF entry to the intake manifold.

 

[seant117]

Got it. She's running perfect now. The new MFI fuel injection I put it went bad. I replaced the fuel injection module and now it's running absolutely perfect! Cylinder 4 injector was dumping fuel into the cylinder and wasn't able to ignite. I'm so happy to have my truck back! Thanks for all your help.

 

[Road Trip]

Got it. She's running perfect now. The new MFI fuel injection I put it went bad. I replaced the fuel injection module and now it's running absolutely perfect! Cylinder 4 injector was dumping fuel into the cylinder and wasn't able to ignite. I'm so happy to have my truck back! Thanks for all your help.

Thank you for closing the troubleshooting loop for the forum by
sharing the fix! The more often folks do this, the clearer our
collective vision is into what tends to ail our aging GMT400s.

Sharing this info is what helps *all* of us down the road, whether
working on our own stuff...or helping others who are experiencing
a similar scenario.

On a side note, once upon a time installing a new part would take
a troubleshooting variable and turn it into a constant. Even if it
didn't fix the problem, you could at least consider this function to
be covered by the Process of Elimination. Not any more - these
days a replaced part is still a troubleshooting variable until such
time that it proves itself to actually work as advertised. (!)

In the worst-case scenario, NEW = Never, Ever, Worked. Not
exactly fair, but as your story illustrates anything is possible.

Good job keeping your '97 on the road. She's a beauty according
to the photo. And welcome to the forum!

Cheers --

 

[HotWheelsBurban]

My cousin is a retired mechanic (fleet, dealership, partner in an independent shop, and still works on his family's vehicles). For decades, he's said,"N-E-W does not spell G-O-O-D".
Even back in my parts store days (mid 70s to late 80s) we had defective parts from time to time. Sometimes it was something that was damaged in shipment, but not initially bad enough to be noticed immediately. This was mostly stuff like distributor caps and spark plugs that had likely been dropped at some point.
Then you'd find threaded parts...with no threads! For a while I had a collection of these, mostly bolts and nuts but there were a few spark plugs in there. Probably any of us who've spent time in parts suppliers or shops has seen a few defective or improperly made parts, and had our share of them. I've had the multi function switch on my Dodge Intrepid be defective (the first one I replaced, failed within a day or two). Good thing it's much easier to change on that car than on the GM trucks! We speculate that the first hydro boost unit replaced on Rawhide was defective, but the part was also poorly installed so that could have contributed to the failure.
Point being, even in the days when most parts were made here, there were some things that weren't made right or didn't hold up as they should.