Head gasket replacement issues 98 k1500 5.7L

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ElCalvinator

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So I bought this truck about a month ago with the intended purpose of being a hunting/beach vehicle. I managed to buy it off the previous owner for a really good price. It ran and drove fine, but there was a suspected head gasket issue as there were some coolant leaks. I've replaced head gaskets on vehicles before, albeit not on a 350, so that didn't really deter me. Managed to drive it home (45 minute drive), noticed it was leaking quite badly from a couple hoses. Replaced those, ran some seafoam through it and all seemed to be well drove fine for about a week or two without issues.

Unfortunately that was short lived as the coolant leaks came back with a vengeance and clearly were coming from the front of the engine. Couldn't tell if it was the intake or the head, but I had already bought a set of gaskets that covered the heads on up when I bought the truck. So decided to replace them all, tear down went without incident. Putting it back together wasn't all that difficult either, however I have now reached the point I realize we did some things out of order. We got the heads back on, lower intake and upper intake put back on, all hoses are back, and electrics are plugged in. But we didn't adjust the valves when the intake manifold was off. I have personally never adjusted valves, but I felt somewhat confident that through youtube and the wonderful world of the internet I could get it figured out. So I spent all day researching and watching videos and a few things I noticed 1. it would be much easier to do with the intake off 2. it can be done with it on though 3. everyone seems to do this differently. So my plan was to adjust them manually by turning the engine and adjusting one cylinder at a time watching for the exhaust valve to open and close and then the intake to open and go to close, then tighten at which point I would start the engine and readjust using that method of loosening the nut until I can here the clapping and then do a half turn.

Unfortunately things didn't seem to go well, I'm assuming I missed some pretty big steps because as we went I started noticing rockers I'd already adjusted getting loose, very loose. At this point it was late and I decided to snug those downs and get it running and adjust while it was going. This is where my bigger issues start to arise. It really struggled to start (it has always had some issues starting up right away) this time it it took a good while and some throttle to get it going, ran for a minute then bogged down and died. I managed to adjust all of two before it died. We gave it a bit and tried again, while adjusting the third one it finally started sounding like it was running well, when I moved to the 4th one and tightened it the engine choked abruptly. Now the engine wont start or turn over almost like the battery or starter has given out. There was also some white smoking coming from the exhaust manifold, i chalked that up to some coolant splashing in there when we removed the heads. At this point I'm just looking for some advice, I think the issues with it running poorly and choking out are largely due to the valves not being adjusted properly, but I'm clearly doing something very wrong with that process and I'm not sure how to resolve it. I also could be wrong and it could be something completely different causing my problems. I'm just at a loss for what I should do next, any help would be greatly appreciated. Slightly related note I just remembered, when I did run the seafoam through the brake booster line it did choke up and die when the break booster wasn't connected to the master cylinder as well. Thanks again.
 

mistaake

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Did you adjust the distributor using a scan tool that can read cmp retard? You have to do that - simply marking it and stabbing it in close enough is not sufficient.
 

ElCalvinator

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I actually did not know I needed to scan for CMP retard. But every thing I am seeing on that seems to indicate that you need to have the truck running for a bit before you can scan. I can only get it to stay running for about a minute. would I need to buy a scanner or is that something they would rent at Autozone?
 

cookseyb

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When you "Re-tightened the valves that got loose" is where you messed up. The first adjustment is ALL you need, the lifters collapsed with no oil pressure when you turned the engine over and the valves seemed too loose but were probably ok.
 

redfishsc

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If you are very cautious about installing the distributor with the engine at TDC1 on compression stroke, and the distributor set to the precise location, you can definitely crank the truck and measure/tweak your CMP retard.

Just be sure you're on the compression stroke with cyl 1. Otherwise you'll be 180 out and I'm pretty sure you'll have an unpleasant experience when you hit the starter.

I just did it successfully on mine a few weeks ago after swapping the intake gaskets (99 Suburban, 5.7). My CMP was only +4 and the tolerances is supposed to be -2 to +2. I have a bluetooth code reader that can read CMP, and I haven't bothered to adjust it because the truck runs like a top 0-80mph no trouble.
 
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