scott37300

I have been searching this all week long and have found so many differing opinions on the right way to do a coolant flush! Some say the T-flush kit and some say don't use that because of tap water. Some say to use a flushing chemical, some say don't.

So what is the right way to do a coolant flush on a 04 impala 3.8L? This is for my grandma's car and that only has 43,000 miles but past the 5 year mark for changing dexcool. I opened the radiator cap and found some "chunks" of stuff, redish brown in color like the fluid and when I grabbed it chunk and rubbed it in my hand it pretty much turned to liquid, in other words not hard or solid chunks. I assume this is from the coolant being almost 7 years old? Also was a little low in the overflow tank.

Some say to just drain and fill with distilled water and run till hot, then drain and repeat until clean and then fill with dexcool and distilled water to a 50/50 mix.

Some say to cut the heater hose and install a T-flush kit and not worry about the little bit of tap water left in after the flush. Just drain after flush and fill with distilled water and dexcool. Some say not to use this kit because it cuts your heater line, put tap water in the system, and isn't neccesary.

Some say to use a flushing chemical that you add and run threw and then drain and then fill with coolant. Some say they don't do much and can cause problems.

Seems like there is someone for and against just about everyway to flush a cooling system! Gets really confusing! Can anyone help sort out the best way to do a coolant flush? I am just trying to do this right and seems like everyone has a different opinion on which way is "right". So how do you guys flush your coolant in the impala?

Thanks, Scott

IggyDenton

I haven't done my Impala yet, but generally you have to remove the thermostat and replace the cover. Pull off the upper radiator hose and open the core. You can jam a garden hose into the radiator hose and flush that way. (FWIW, I use a device that mixes compressed air with the water). Replace the thermostat, reattach the hose, Refill the system. I never use a commercial flushing chemical. I just run the water until it comes out clean.

Distilled water? Really? This is the newest car I've owned by a margin of 14 years, so I haven't distilled water in the radiator yet.

scott37300

Thanks for the reply Iggy. I ended up buying a factory repair manual because there was so much conflicting information on the web on how to flush the cooling system, distilled or non, T-flush kit or not, etc, etc, etc. The factory manul states to just drain and fill with water and drive till hot and then drain. Repeat until fluid comes out clear. Then fill with right coolant.

HotSauce6226

Doing a flush is the worst thing you can do.

scott37300

Hotsauce, can you explain why a coolant flush is so bad. I've read about transfer flushes being bad but never heard that coolant flushes are so bad.

Right now I plan on just draining and refilling with distilled water and repeat a couple times to "flush" the cooling system. I went to some other sites since there wasn't to much activity on here and there is so many differing opinions out there.

Thanks for any advice

gotstylez

the way i did it on my truck was drain the coolant..refill and drain with water from the waterhose a few times.. put some dishsoap in fill it back up run it til the thermostat opens drain and fill a few times. finally fill with coolant

scott37300

After much reading on many forums I plan on doing as you stated, just drain, fill with water and run till hot, drain and repeat as neccasary until clean and then fill with new coolant.

gotstylez

make sure u pour in dish soap..then run it hot and drain and fill up a few times...... it helps get alot of the inside on your engine clean........when i did this to my truck it had mostly water in the coolant system..it was a rusty color..when i just did the dran and fill a few times it got it clean bu when i did it soap..it was like i jst started again.. it helps alot

scott37300

Thanks for the tip. I assume you need to use the dish soap for the dishwasher and not the regular dawn? I know you can't use dawn in the dishwasher cause it will bubble up like crazy so I assume the same would happen running it threw the cooling system.

gotstylez

no..i used dawn..... thats why u drain and refil about 6 times.. lol also after u use the soap and drain a time or 2...drive it about a mile... that help alot also