Thread: radiator flush

EDIT: And yes, I have used the search! There are a few topics about flushes, but the information is very jumbled and non-informative!

well, 180k miles later, the coolant has become so rusty it's turned into a jelly substance. it clogged and blew the head gaskets, blew the thermostat, cracked the heater core, and became too much for the water pump to handle.

i just finished rebuilding the motor, alongside some new mods.

CAI
3.5" pulley
autolite 104s
autolite 8mm plugs
180* tstat
speed daddy headers
custom-tuned PCM

preventative maintenance is complete, including fuel, oil, and trans filter, etc.

some asshat stabbed my tires last year just as the head gasket went out, which REALLY discouraged my love for GTPs. i tried selling it, but then changed my mind and decided to tackle it head-on and get it done.

now i've got some new tires and have made some interior modifications, but the overheating problem still exists! (i figured i'd give a little background. :P) i will admit, being able to test-drive for two minutes gives me many oohs and ahhs thrills, but i'd like it to last much longer.

i work at autozone and decided to buy some prestone super radiator flush. it's about a quart i believe of some supposed super-powered sodium-silicate. i've been reading up on guides to flush for a while now, but now that i have the flush kit, coolant, and solvent, i'm stuck.

i can't find the draincock on our radiators. i've seen pictures of new radiators with what appears to be a drain plug on each side, but i'm unsure. i've looked all over under the car and i've seen a rubber plug on each side, but i have no idea how to open those suckers up. am i looking in the right place?

next, what is the most efficient way to flush these darn things? i keep reading confusing guides with hose tees and splash deflectors (which i have), but they're generic guides and not for 3800s.

do i want to run the solvent and fill with water to flush, then run 50/50 green coolant and green full-strength antifreeze when i finally refill? note i say green coolant because i will never go back to dex-cool. i know some of you defend it, but working in a semi-automotive retail environment, i've seen the effects of dex-cool on MANY W-bodies from customers that come to our store.

thanks for the help guys. this is the one last thing keeping my car from being on the road. i've been working on it for 8 months, slowly adding to it and changing things, making fixes. it was a total piece of sh*t when i bought it. i can't wait to hear her scream now!

Hey just read your novel lol!! I can tell you everything you need to know, however i am at work right now, but will b off here in about an hour or so!! I went through this exact same thing trying to find info on flushing the radiator on my gtp, and never really found anything, however a local gp memeber and i tackled it and figured it out, and also took pics for this very reason just havent posted them yet!! But when i get home and settled i will hit you back and fill you in

wow thank you very much! i really appreciate it. i've been looking around everywhere for any info i can get, but nothing seems to have helped much. you're a lifesaver!

I am interested too. I will wait to see what you have to show us.

the drain is on the driver's side of the rad at the bottom..its green. open that up and drain all the coolant out of the rad. Close the plug. Fill the rad up with water, and the bottle of rad flush. Let the car run for 15 minutes or so to let the system cycle a few times, shut it off and drain the rad again. Don't burn yourself the water will obviously be hot. Fill it up again with water, and let the car run with the drain open, continuously filling at the top with a hose or something. when you see the water coming out the bottom is clean, let it all drain out, close the plug, fill it up with 50/50 mix...DONE

youll more than likely break the drain plug if you use it. just pull the lower radiator hose, its easier, but a little messier too.

good tips! i'll go out there right now and begin the process.

alright bio, your hose trick was a good idea. in the course of 2-3 hours, i got the radiator flushed out about five or six times. i got it to where it was pure clear water running out. engine was still heating up too quickly and overheating, so i pulled the upper hose and put a bucket under to make sure coolant was circulating. turns out it was, but the cooling fans aren't coming on.

i've checked all fuses, they're fine. i'll have to buy some new relays from my store and see if those help, but other than that, i don't believe there are any fuses or relays i'd need to worry about.

any suggestions besides a bug in the harness that i might be overlooking?

Damn, sorry bro....i never got back to ya the other night...just been slammed workin and doin shows!! It seems you have figured it out however with the help from some fellow Gpr's

When i can get time to do it, I will make a write-up for this!! I have more than a few pics of the process somewhere around here from when Iron Indian and I did mine, and took the pics for this very reason!!

no problem, i figured out the issue. i'll post a guide of my own right now.