Rusty Block!
Powerarranger
10-29-2006, 08:46 AM
In reference to this thread (http://www.automotiveforums.com/vbulletin/showthread.php?t=536633), I've finally found the time to pull the motor and address the issues, namely, leaking core plugs and a rod knock on #6. It's a 4.3 VIN W in a 1993 Jimmy SLE with 230K on the clock.
The engine is in surprisingly good condition. I've decided to do a rebuild since all of the cylinders still have the factory hone marks and there's no ridge except for some carbon. The rod knock was minor, hardly noticeable, but went on for a few years. The core plugs leaked really badly after I repaired the problems referenced in the other thread, so I was forced to run straight water all summer.
The inside of the block looks very rusty from having no antifreeze all summer. The inside of the hoses and radiator have the same rust haze coating the interior. Otherwise, the system is very clean - no sludge. Could some of the color may be residue from the Dex-Cool that was in the system before?
The big question - is this rust in the cooling system going to be a problem? Do I have to replace the radiator (almost new) and other parts because of this? Or will the antifreeze neutralize the rust? I'm sending the block to a machine shop to be tanked - will this be enough?
I have some other questions, but I'll save 'em for later. Thanks!
The engine is in surprisingly good condition. I've decided to do a rebuild since all of the cylinders still have the factory hone marks and there's no ridge except for some carbon. The rod knock was minor, hardly noticeable, but went on for a few years. The core plugs leaked really badly after I repaired the problems referenced in the other thread, so I was forced to run straight water all summer.
The inside of the block looks very rusty from having no antifreeze all summer. The inside of the hoses and radiator have the same rust haze coating the interior. Otherwise, the system is very clean - no sludge. Could some of the color may be residue from the Dex-Cool that was in the system before?
The big question - is this rust in the cooling system going to be a problem? Do I have to replace the radiator (almost new) and other parts because of this? Or will the antifreeze neutralize the rust? I'm sending the block to a machine shop to be tanked - will this be enough?
I have some other questions, but I'll save 'em for later. Thanks!
Blue Bowtie
10-29-2006, 04:14 PM
After the block is hot-tanked, and BEFORE the cam bearings, core plugs, and gallery plugs are installed, get the block back from them. Remove any remaining plugs, get a rifle cleaning brush set and heavy duty solvent or degreaser/cleaner. Run a .50 Calibre bore brush through the full length of the lifter oil galleries and upper main oil gallery. Flip the block and run a .22 or .30 calibre bore brush through all four of the main (vertical) oil galleries between the cam bearing bores and main saddles. Run a .50 caliber brush up the main oil line from the rear main cap to the upper (cam/lifter) oil galleries. Flush/brush everything out until it's clear. You might want to do the same with the oil passages in the crankshaft.
Use a bent wire, coat hanger, hose brushes, or whatever is necessary to reach through the core plug opnings and loosen all the scale in the cooling jackets. Rinse out everything with a strong stream from a garden hose or whatever is appropriate to blast out the loosened debris.
When you're satisfied, take the block back and have it tanked again to completely clean it out (Their first tanking will likely have only loosened a lot sludge in the lubrication system and scale in the cooling system, but likely will not have cleared it all out). Only then should the cam bearings be pulled into place, and the oil gallery and core plugs installed.
White enamel on the inside has always worked well for me. Paint the exterior whatever color you like.
Use a bent wire, coat hanger, hose brushes, or whatever is necessary to reach through the core plug opnings and loosen all the scale in the cooling jackets. Rinse out everything with a strong stream from a garden hose or whatever is appropriate to blast out the loosened debris.
When you're satisfied, take the block back and have it tanked again to completely clean it out (Their first tanking will likely have only loosened a lot sludge in the lubrication system and scale in the cooling system, but likely will not have cleared it all out). Only then should the cam bearings be pulled into place, and the oil gallery and core plugs installed.
White enamel on the inside has always worked well for me. Paint the exterior whatever color you like.
534BC
10-30-2006, 10:14 AM
An oven and blaster will do nicely regardless of how much rust/grunge there is. Usually it is same price if you find a shop that uses it regularly.
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