dante2 Posted May 14, 2022 Share Posted May 14, 2022 Broke the rear stud for the exhaust manifold inside the head. Being in the back it's damn near impossible to get a straight shot at it. So to ease pain and less cussing I'm pulling the head. While the head is off is there any thing that I should look at or replace? 135K on mileage and dry compression is 142 on the low side and 151 on the high side. Link to comment Share on other sites More sharing options...
89 MJ Posted May 14, 2022 Share Posted May 14, 2022 If I were you, I’d do the headgasket, intake and exhaust manifold gasket, valve cover gasket, and maybe to plugs and wires while you have it that far apart. Link to comment Share on other sites More sharing options...
75sv1 Posted May 14, 2022 Share Posted May 14, 2022 I'd probably have the valves done. Head cleaned etc. I'd check the lifters and camshaft for wear. I would not pull the camshaft. I might look at going to a .042 head gasket. Link to comment Share on other sites More sharing options...
cruiser54 Posted May 15, 2022 Share Posted May 15, 2022 Unless you're just hellbent on spending money during these inflationary times, new gaskets and back together with it. Link to comment Share on other sites More sharing options...
AZJeff Posted May 15, 2022 Share Posted May 15, 2022 I vote with Cruiser's advice. I am a big fan of "do it once, and do it right", but I don't see the need to "refresh" a head with those compression numbers. Link to comment Share on other sites More sharing options...
DirtyComanche Posted May 16, 2022 Share Posted May 16, 2022 I'm in the crowd of throwing new gaskets at it and putting it back together. Those dry numbers are great. Also if the stud didn't break flush or below I'd just take it out with the welder. 10 minutes to do that if it goes well. Link to comment Share on other sites More sharing options...
gvthnks Posted May 16, 2022 Share Posted May 16, 2022 Id take a hard look at expansion plugs while it's out. They're cheap, and a pain to get to with everything in place in the truck Link to comment Share on other sites More sharing options...
dante2 Posted May 26, 2022 Author Share Posted May 26, 2022 Ok got the stud out in one piece this last weekend. Now I have another question. Can you test a CPS with the head off? Should have checked it before I pulled everything apart. I ended up rolling/pulling it into the shop because of a no start. Never going to have an easier time to change than right now with nothing in the way. Link to comment Share on other sites More sharing options...
cruiser54 Posted May 26, 2022 Share Posted May 26, 2022 there's an ohms test which is unreliable. Link to comment Share on other sites More sharing options...
dante2 Posted June 27, 2022 Author Share Posted June 27, 2022 Update Last week I got the engine all put back together and changed out the CPS. Got it started, idled up to 2k and back down to normal after a second or two. After about 10 seconds it sounded wrong like a light knock and bad exhaust leak. I looked at the engine thru the oil cap, no oil. I made a primer tool and spun the pump for a bit and got oil flowing. Day late and a dollar short, now the engine is toast. Today I pulled the pan to see how bad it is. No shavings in the pan and no shiny bits on the engine. I pulled all of the rod caps and so far no.5 main cap. Rod bearings don't look real bad. Very smooth, a little copper color showing, and the markings on the bearings are easy to read. My issue is the main cap and bearing half that I pulled. Under the bearing the cap looks bad but is smooth just discolored. Journal side of the bearing is showing discoloration at the edges. Crank journal looks and feels like it just came back from the machine shop. I also checked 2 cylinders for wear also smooth but can't any cross hatching from below. Sorry for the long winded post. So after all that how bad does it sound? Adding pics of the main cap and bearing half. Link to comment Share on other sites More sharing options...
Eagle Posted June 27, 2022 Share Posted June 27, 2022 You have it apart -- throw in a set of bearings. Link to comment Share on other sites More sharing options...
dante2 Posted June 27, 2022 Author Share Posted June 27, 2022 My thought process too. Both rod and main? Going to get the rear main seal while I'm in there. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 27, 2022 Share Posted June 27, 2022 2 hours ago, Eagle said: You have it apart -- throw in a set of bearings. My thoughts exactly. I don't think I would have torn it apart but now that you have, replace the bearings. Use plenty of assembly lube. Why wasn’t your oil pump working? Link to comment Share on other sites More sharing options...
dante2 Posted June 27, 2022 Author Share Posted June 27, 2022 The way it sounded I thought I spun every bearing. It hasn't been driven in a while so I'm guessing the oil pump lost it's prime. Should have been thinking after this long, "your basically working with a new engine so plan accordingly". Nope brain left the building that day. Link to comment Share on other sites More sharing options...
75sv1 Posted June 28, 2022 Share Posted June 28, 2022 Yeah, looks like just new bearings. Don't know how much you are replacing, like the camshaft etc. I might get some Rotella T1 30 weight oil. I might put in some GM EOS or Motor Honey. If you put in a new camshaft, then you'd need to coat the lobes. Also, then ignore next. I like to spin the engine before it fires up, to get oil pressure. I do that for an oil change. I pull the distributor wire. Link to comment Share on other sites More sharing options...
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