NOTE: i will be adding pictures soon to make this guide more aesthetically pleasing and comfortable for new DIYers!
subnote: would also be much appreciated if a mod could stick this in the how-to section! thank you!
thanks to some helpful members on this forum and the interweb, i've figured out how to revive my dying cooling system efficiently, quickly, and easier than the methods you've read about in other places. read this guide slowly and carefully. if you follow everything in the right order, you'll be on your way to a smooth, cool-running 3800!
the dex-cool had turned into such a harmful sludge in my engine that i could rub my finger inside a radiator hose and pull out what appeared to be orange paint on my finger. it was VERY solid. i can't believe the champ that my car is ran so long on that crap! unfortunately it did shred some of the cores on my radiator, which i will be replacing soon. luckily my water pump is still kicking!
i'm going to go out on a limb and say that i strongly believe that my cooling system was more neglected than anyone else's on this forum. i don't think the coolant was ever changed in the 181,248 miles of my car's existence. the prior owner had all tech receipts EXCEPT for routine maintenance with antifreeze, which i never thought anything of until after my head gasket blew. why he didn't change it? i have no idea. i'm going to guess because he thought dex-cool would last forever. but that's in the past. this is now. no time to wonder, now for solutions.
so here's how it goes down.
TOOLS NEEDED:
shop towels or rags
vice grips or something to grip the spring clamps with
prestone radiator flush or super radiator cleaner (sold at your local auto parts store for about 5-6 bucks per bottle)
garden hose (well water, city water, or distilled; anything you put in there at this point is going to make you better off than that nasty coolant)
POSSIBLE NEW PARTS TO ADD WHILE DOING THIS MAINTENANCE:
radiator hoses
thermostat
radiator cap
first, instead of pulling the draincock and risking damage to it, i followed bio's advice and pulled the LOWER radiator hose (hose closest to the battery). have your car jacked up and have a large bucket ready to catch the coolant! this way is sloppier than the draincock, but it is much more efficient and gets the largest gobs of sludge out best. be prepared to get a little dirty!
for those of you that actually use your heater core, make sure you have it running full speed throughout these exercises. that way it's getting the cleaning it needs as well! be sure to check your interior carpeting for leaks in case the new coolant spawns leaks that were plugged by the old. i bypassed mine, so i had no need to worry about it for this guide. installed or not, it makes no difference, however!
now, depending on how bad your system is, you're going to want to take a garden hose, open your radiator cap, and spray all of that crap out of the reservoir ( LOWER hose is still off at this point.) move the garden hose around inside of the neck, while kinking and unkinking it to give it bursts of water to spray out that stubborn sludge. once that is cleaned out, reconnect your LOWER hose nice and tight, then fill up the water to the top of the neck. seal the cap, then turn on the engine. remember to bleed the system of any air inside! turn the bleeder valve on the thermostat housing OPEN a couple of turns and wait until coolant begins to trickle out, then CLOSE it. at this point, turn off the engine, remove the cap, and top the neck off with water. WARNING: DO NOT remove the cap if your engine has warmed up at this point. let it cool down first unless you want to risk burning your limbs/face! nobody likes a freddy kreuger!
now for the fun part. turn her back on, then take her for a nice drive. and by nice, i mean beat the hell out of her. make that lady STUPID hot. if you were overheating before, get her somewhat close to the danger zone. but be careful if you had to take the engine apart like i did to fix any plugged gaskets or runners! you don't want to make the same mistake twice and start all over again. if she doesn't overheat after beating on her, at least you're already making progress. put her back on the jack stands and pop that LOWER hose once more. any solid sludge that was in there before should now be a pretty fine liquid and will pour out of that housing, steaming and all, like a fresh dog turd! but much more reassuring.alright stop smirking! (you know it tickled your humor just a little bit) reattach that LOWER hose and lets start getting serious.
while we're here, since you're obviously having cooling system issues, i hope you replaced your thermostat. lets check that now and make sure it's working fine and able to handle the semi-sludge based water. disconnect your UPPER radiator hose (hose closest to the PCM/intake tubing) and place a bucket somewhere underneath where it'll catch the water. remove your radiator cap (when cool) and place your garden hose in the neck. turn the engine back on and let the water flow from the garden hose. wait until the temp hits whatever temperature your tstat is set to (mine is 180*. i recommend everyone use this temp as an upgrade replacement unless going colder for intercooled applications. 160 is a bit overkill, in my opinion, if you're running standard bolt-ons or stock.) so it will open and allow the water to travel through. at this point you should see a modest amount of fluid rushing out of the UPPER hose and down into your bucket. let this flow until it's clear- that way you know that your block, heater core, and the rest of your system is cleaning out. note that since you are forcing cold water in your system, the thermostat may stay shut. in this case, pull the garden hose out and let the water warm up inside. rinse and repeat.
once the water is pretty clear, turn off the engine and reconnect the UPPER hose. at this point, your cooling system is starting to be able to handle breathing fresh new coolant. but not just yet! there are a few more things left to do to ensure that things stay safe and work in proper function.
one thing i did that you don't have to do (and is messy) is take off your radiator cap, turn on the engine, and let the water you have inside boil out. this method clears out your radiator, as the water that is fresh out of circulation from the fins is going to spit out at the neck. you could just keep dropping the LOWER radiator hose, but you never know what's in front of the flow with a constant visual. plus you'll get gunk buildup at the bottom of the radiator. and it's a pain to keep dealing with those spring clamps all the way down there. not much room to grab them with vice grips!
if you decide to boil out your radiator neck, cover all of your electrical. coils, alternator, battery, any exposed wires need to be covered. boiling water is going to spit out of the neck and believe me it spits far. if you have rusty coolant, be prepared to wipe down the pulley side of your bay if you take pride in your 3800's appearance like i do.also, REMEMBER TO KEEP ADDING WATER AS MORE SPITS OUT! you DO NOT want your engine to run dry of cooling! just hold your garden hose over the radiator neck and let water pour in. just hold it high enough to avoid getting splashed by boiling coolant. don't worry, when the cold water hits the boiling, it'll stop splashing out until it gets hot again, which will be within 10 seconds of removing the flow from the garden hose.
next. turn off your engine, seal the radiator cap, and let it cool. by this point, the water coming out of any radiator opening or hose should be mostly clear. there are a couple more steps!
NOTE: make sure you're checking your temp constantly while having the engine on. if it continues to overheat at this step, you need to keep flushing until that water is clear. repeat all steps until clear! you're almost at the stage to test-drive, so it needs to be emptied out of all contaminants and sediment!
once the engine is cold, pull your lower hose and drain your system. now is the time to clean out your overflow tank! unclip the buttons (or bolts, depending on the year) that hold it in place and empty that disgusting thing out. pour some hot soapy water in there and do whatever you have to do to clean it out! shake it up, spray it out, whatever works. replace it and hold off on filling it for now. while you have it out, check for any cracks, leaks, or sealing issues with the cap. my cap had a cracked gasket and was always leaking coolant around and on top of the PCM! not good!
this is where the fun part comes in. pull out your radiator flushing solvent! here's the final step to ensuring your renewed cooling system rocks the old coolant's face off. remember, your cooling system should be EMPTY of any liquids at this point and ALL hoses should be clamped down, valves CLOSED!
this is where you really want to make things nice and right. open your radiator cap. pour all of your flushing solvent down inside. when it's empty, stick your garden hose inside the neck. fill to the top! seal the cap, turn on the engine. OPEN your bleeder valve on the thermostat housing! when it trickles, CLOSE it! turn off your engine. let it cool down. repeat this process until you can successfully open your cap after a cool down and the water is still at the top of the neck. you want your system as full as possible!
and now? drive. drive for 3-6 hours. fill up that gas tank and have a ball. while at it, drop some fuel injector cleaner in your tank just as some added security that you're continuously repowering your engine. keep that beast kicking strong!
when you've successfully driven the long drive, take it home and pull that LOWER hose once more WITH THE ENGINE HOT. BE CAREFUL NOT TO BURN YOURSELF! oh look at the rest of that ugly gum and varnish spill out!
congrats! you've brought your cooling system back to life. if you want, continue to repeat the final step until you're comfortable. unfortunately it is damn near impossible to get it all out of there, but 98% of it being gone is better than 2% of it. :P
fill your system with 50/50 and water. i'll say about 30% 50/50, 70% water. go green coolant. not dex-cool. !@#$ that sh*t. don't forget to fill your overflow reservoir!
enjoy your cooler cooling system! if you still want to run colder and aren't satisfied, drop your thermostat temp and get an aftermarket cooling fan switch. set that beast to run continuously and you'll probably never overheat again, unless you decide to go years upon years of neglect once more. then you're more than welcomed to return to this guide. just don't tell me, because i'll have to kill you for abusing your 3800.
if that still isn't enough for you, ZZP sells electric water pumps, which do a better job at cooling things down without the HP loss and OE restrictions.
just as a heads-up, check your radiator fins, hoses, thermostat housing, water pump, and any other cooling surface connections for signs of leakage. old coolant may have blocked these areas and when adding water, you may have opened the leak! for radiator leaks, liquid aluminum works very well for stopleaks! sold at your local auto parts store for about 10 bucks a bottle.
i hope this guide was informative. it's a long read, but if you follow step-by-step, your system will be golden!
cheers.
...mine has 173k on it and it was never changed!...(got the car 6 months ago from her mom,for FREE)...if it was low on DEX-Cool she would add whatever(coolant) she could find!...other than that the car was takin care of.Im replacing the intake gaskets as we speak(this is the first time the motor has been apart since its date of birth in 2000)...this is going into my favorites!..WELL DONE!
