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- Oct 28, 2014
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GM 3.8 L upper and lower intake gasket replacement
You can watch this guy do it with you in about 20 minutes for disassembly. I have personally done this more times than I can remember, for my own and friends and neighbors cars. Start by washing the engine gently from the top with Dawn dishwashing soap (or any gentle degreaser you are comfortable with) and idling it until dry, then vacuuming any debris remaining from the intake manifold. Remember, you are opening the engine internally, so you cannot be too clean.
I can save a LOT of time and trouble by using a battery syringe with a long pickup tube on it and patiently dipping and sucking coolant out the radiator cap: http://www.ebay.com/itm/Lubrimatic-Syringe-Battery-Filler-/281815440372?hash=item419d825bf4:g:e~IAAOSwgZ1XvQsv Twist it, work it down into the radiator until you have the bulb sitting on the radiator cap opening, go as deep into the radiator as you can to suck out fluid.
It seems tedious when you are sucking fluid out the radiator a few ounces at a time, then removing the upper radiator hose at the thermostat, jacking the car a little on the passenger side to get the engine to tilt and sucking all the antifreeze you can reach, and soaking up the last few drops with rags, but the payback is that I leave NO mess of antifreeze on the garage floor, vacuum and use clean rags carefully and meticulously to immediately "sponge up" any remaining liquid from the intake valley when you first lift the lower intake (and have clean rags immediately at hand). The payback is not only in no wasted antifreeze and a clean garage floor, but I have done this several times WITHOUT changing my $50 of synthetic oil and followed with UOA to verify results in a few thousand miles, no contamination in oil.
These GM 3.8L are wonderful engines, with ideal oil pressure and all steel timing chains and gears, but the intake gaskets are weak points that need to be addressed. Make sure you use the aluminum lower gaskets with neoprene liners; and don't forget to use aluminum coolant elbows rather than the OEM plastic trash: http://zzperformance.com/3800/gaskets-adhesives/intake-gasket.html Coolant elbows: http://zzperformance.com/3800/gaskets-adhesives/aluminum-coolant-elbows.html
I also work through the torquing sequence going 22-44-89 INCH PUONDS about 3 times; use motor oil and lubricate the injector O-rings really well, clean out the machined holes they go in with brake fluid and rags like a gun barrel, then re-assemble things just enough to start the car...Let it idle just enough to get to operating temperature, shut it down and re-torque your upper intake bolts to 90 inch pounds a couple more times.
Short of some old lady T boning your car and destroying it, there is no reason NOT to get another 175K out of this car.
You can watch this guy do it with you in about 20 minutes for disassembly. I have personally done this more times than I can remember, for my own and friends and neighbors cars. Start by washing the engine gently from the top with Dawn dishwashing soap (or any gentle degreaser you are comfortable with) and idling it until dry, then vacuuming any debris remaining from the intake manifold. Remember, you are opening the engine internally, so you cannot be too clean.
I can save a LOT of time and trouble by using a battery syringe with a long pickup tube on it and patiently dipping and sucking coolant out the radiator cap: http://www.ebay.com/itm/Lubrimatic-Syringe-Battery-Filler-/281815440372?hash=item419d825bf4:g:e~IAAOSwgZ1XvQsv Twist it, work it down into the radiator until you have the bulb sitting on the radiator cap opening, go as deep into the radiator as you can to suck out fluid.
It seems tedious when you are sucking fluid out the radiator a few ounces at a time, then removing the upper radiator hose at the thermostat, jacking the car a little on the passenger side to get the engine to tilt and sucking all the antifreeze you can reach, and soaking up the last few drops with rags, but the payback is that I leave NO mess of antifreeze on the garage floor, vacuum and use clean rags carefully and meticulously to immediately "sponge up" any remaining liquid from the intake valley when you first lift the lower intake (and have clean rags immediately at hand). The payback is not only in no wasted antifreeze and a clean garage floor, but I have done this several times WITHOUT changing my $50 of synthetic oil and followed with UOA to verify results in a few thousand miles, no contamination in oil.
These GM 3.8L are wonderful engines, with ideal oil pressure and all steel timing chains and gears, but the intake gaskets are weak points that need to be addressed. Make sure you use the aluminum lower gaskets with neoprene liners; and don't forget to use aluminum coolant elbows rather than the OEM plastic trash: http://zzperformance.com/3800/gaskets-adhesives/intake-gasket.html Coolant elbows: http://zzperformance.com/3800/gaskets-adhesives/aluminum-coolant-elbows.html
I also work through the torquing sequence going 22-44-89 INCH PUONDS about 3 times; use motor oil and lubricate the injector O-rings really well, clean out the machined holes they go in with brake fluid and rags like a gun barrel, then re-assemble things just enough to start the car...Let it idle just enough to get to operating temperature, shut it down and re-torque your upper intake bolts to 90 inch pounds a couple more times.
Short of some old lady T boning your car and destroying it, there is no reason NOT to get another 175K out of this car.