4.3L Vortec Getting a Rebuild
#11
From Les in the other thread:
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
#12
Sounds like a plan.
Be sure to not sand or use abrasive pads or wire brushes of any kind on the gasket surfaces (like some people will tell you to use). Razor blades or putty knife sharpened with a file, and carb cleaner only over clean shop rags - and vacuum out any remaining gasket debris. You dont want abrasives or wire pieces or anything else left inside the engine and/or getting on the piston rings and cylinder walls. Keep the rockers and pushrods in order.
I think you can still buy new exhaust manifolds if necessary.
Oil up the open cylinders so they dont start to rust while the head is off. I assume you have a garage to work in during the cold weather.
Don't let the machine shop do anything more than fix the one valve/valve guide if compression is OK on other cylinders. I would check them all before teardown.
Keep us posted!
Be sure to not sand or use abrasive pads or wire brushes of any kind on the gasket surfaces (like some people will tell you to use). Razor blades or putty knife sharpened with a file, and carb cleaner only over clean shop rags - and vacuum out any remaining gasket debris. You dont want abrasives or wire pieces or anything else left inside the engine and/or getting on the piston rings and cylinder walls. Keep the rockers and pushrods in order.
I think you can still buy new exhaust manifolds if necessary.
Oil up the open cylinders so they dont start to rust while the head is off. I assume you have a garage to work in during the cold weather.
Don't let the machine shop do anything more than fix the one valve/valve guide if compression is OK on other cylinders. I would check them all before teardown.
Keep us posted!
Last edited by LesMyer; 01-15-2022 at 11:51 PM.
#13
From Les in the other thread:
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
#15
If you end up pulling the engine your biggest challenge as said above is getting access to the upper drivers side bolts to the bell housing. The manual says (and turns out to be right) to remove the body mounts under the radiator and jack up the body enough to get access to the 2 bolts.I removed those plus one on each side below the front doors.Had to put couple of 4x4 wood blocks on the jack to raise it up enough. It will give you a few inches but is enough to access the bolts - just takes time. Note: When you install the flex plate make sure to put it on correctly. It will bolt on either side. When I went to bolt it to the trans the bolts were too short. Pulled it back out again and took off the flex plate - turned it over and and stamped in big capital letters are "THIS SIDE OUT". Also, If it's your 1st time like mine was, bag and tag everything and take lots of pics/video. Mine was a project and not a daily driver so I tore it down and took the block and heads to the machine shop. Had the shop order my rebuild kit and did the rebuild myself. In the log run it would have been cheaper and faster to order a crate engine but I was doing it for the experience. It's pretty cool driving something you built yourself.
#16
If you end up pulling the engine your biggest challenge as said above is getting access to the upper drivers side bolts to the bell housing. The manual says (and turns out to be right) to remove the body mounts under the radiator and jack up the body enough to get access to the 2 bolts.I removed those plus one on each side below the front doors.Had to put couple of 4x4 wood blocks on the jack to raise it up enough. It will give you a few inches but is enough to access the bolts - just takes time. Note: When you install the flex plate make sure to put it on correctly. It will bolt on either side. When I went to bolt it to the trans the bolts were too short. Pulled it back out again and took off the flex plate - turned it over and and stamped in big capital letters are "THIS SIDE OUT". Also, If it's your 1st time like mine was, bag and tag everything and take lots of pics/video. Mine was a project and not a daily driver so I tore it down and took the block and heads to the machine shop. Had the shop order my rebuild kit and did the rebuild myself. In the log run it would have been cheaper and faster to order a crate engine but I was doing it for the experience. It's pretty cool driving something you built yourself.
Last edited by LesMyer; 01-16-2022 at 12:16 AM.
#17
Oh man, I know... The regret I have for not just going out and getting a compression tester and testing it when Les first mentioned that is crazy. Or even just getting a helper and doing a thumb test I could have found it that way too. You live you learn. I was running in circles barking up the wrong tree, looking back there are many things that stand out to me now that pointed to something else going on. But of course, that's easy to say now that I know what's really going on. Unfortunately, I just don't have space in the garage for the blazer, it doesn't even fit in the garage anymore with the roof rack and spare tire up top lol. That's also part of the reason why I want to pull the engine if I do decide to repair it, I would be able to keep the engine in my garage at least and I could work on it in the warm. Also, get the oil pan and rear main seal situation fixed up. Thanks Steve for the tips, I have not mentioned yet that I do have a 2" body lift installed as well so that should help some with the space and getting that bell housing bolt. Haha Les well that would be the case if I didn't do the lift but thankfully for me all the bolts are brand new so they should come out with no problem now if I do need more space.
#18
Oh man, I know... The regret I have for not just going out and getting a compression tester and testing it when Les first mentioned that is crazy. Or even just getting a helper and doing a thumb test I could have found it that way too. You live you learn. I was running in circles barking up the wrong tree, looking back there are many things that stand out to me now that pointed to something else going on. But of course, that's easy to say now that I know what's really going on. Unfortunately, I just don't have space in the garage for the blazer, it doesn't even fit in the garage anymore with the roof rack and spare tire up top lol. That's also part of the reason why I want to pull the engine if I do decide to repair it, I would be able to keep the engine in my garage at least and I could work on it in the warm. Also, get the oil pan and rear main seal situation fixed up. Thanks Steve for the tips, I have not mentioned yet that I do have a 2" body lift installed as well so that should help some with the space and getting that bell housing bolt. Haha Les well that would be the case if I didn't do the lift but thankfully for me all the bolts are brand new so they should come out with no problem now if I do need more space.
From Les in the other thread:
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
"Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation."
Man that turned out to be an impressive call. Just sayin'
George
As you said, you'll get some of the other issues fixed up properly while you are at it.
Here's one more you can address when the engine is out: Replacing the remote oil cooling lines!
#19
Oh man, I know... The regret I have for not just going out and getting a compression tester and testing it when Les first mentioned that is crazy. Or even just getting a helper and doing a thumb test I could have found it that way too. You live you learn. I was running in circles barking up the wrong tree, looking back there are many things that stand out to me now that pointed to something else going on. But of course, that's easy to say now that I know what's really going on. Unfortunately, I just don't have space in the garage for the blazer, it doesn't even fit in the garage anymore with the roof rack and spare tire up top lol. That's also part of the reason why I want to pull the engine if I do decide to repair it, I would be able to keep the engine in my garage at least and I could work on it in the warm. Also, get the oil pan and rear main seal situation fixed up. Thanks Steve for the tips, I have not mentioned yet that I do have a 2" body lift installed as well so that should help some with the space and getting that bell housing bolt. Haha Les well that would be the case if I didn't do the lift but thankfully for me all the bolts are brand new so they should come out with no problem now if I do need more space.
Last edited by LesMyer; 01-16-2022 at 09:03 AM.