Gunky Coolant.. vaccum flush or drain it?

[00firebird]

Finally got the bright idea that my coolant was the source of my problems.. I've had all the symptoms of my heater not working very well, and i've been burning about 2 quarts of oil a month. engine temps appear normal however and i couldn't find any leaks. checked my dipstick and my dexcool is literally like the consistency of POOP. I know this is a problem with GMs, and it was bad enough to kill engines.. so I want to fix it ASAP and put in the green stuff.
Now i spoke with a mechanic and he recommended putting it on his machine and flushing it with detergents and sucking them out.. I remember reading prior some saying not to do this.. i asked about bad side effects and he did say it can mess up the heater or hoses, but it is the only way to get it out. Then said it is too late because the gunk is already in the engine anyway, so you need to get it out. Do you guys generally agree with this?

Or is this a terrible idea and risks damaging other areas of the engine/radiator etc? If theres a solution more simple such as "pour in this chemical, let sit for 12 hours, drain out fluid, done." then i'd love to know. thanks in advance.

[Kwazrollinz28]

eeek, i did this 3 years ago, and it ate away at what i had left of my headgasket, then i had to take the engine apart.

[bigjon88]

I have had 4 cars done with the vac no problems ever

[Fbomb]

When I switched mine I ran straight water first, two cycles over about two months time.

[SSTODD]

I do not know if you are a V8 but, the dipstick on my V8 is on the overflow bottle under the battery. No flush or machine will clean or replace the overflow bottle and fluid so I suggest replacing the bottle/battery tray with a new one and filling with new coolant. it is cheap and easy to do, then I would use a machine to flush the system coolant with no solvants but just new coolant and I would stay with Dexcool and just maintain it. I heard the cleaning/solvants can cause issues, I drain my radiator only every year and replace with new pre-mix dexcool so I am replacing almost half the fluid every year to keep it fresh.

[00firebird]

I found this process on another website asking the same question, here was the advice. if someone has more experience with this stuff i'd be willing to pay about $100.

What your going to want to do is pull the thermostat out, next drain the radiator and pull both knock sensors(you will need a deep 22mm socket for this) which will drain the block. next step is run your with the knock sensors our and try to flush the block to some degree through the upper radiator hose. You may have to chunk out the hardened dexacrap after pulling the knock sensors to get coolant to come out. trust me there is a good gallon of coolant hiding in the block. Put the knock sensors back in. Now close off the radiator/pull the lower hose and put the cap back on. attempt to fill the radiator through the upper hose. this will attempt to push out the gunk through the lower hose. You will want to do the same with the heater core. once you seem to be getting clean water from both the core and the radiator and the block appears the be clean, your next step is to put the lower hose back on but keep it disconnected from the engine. same with the upper hose. Now you will want to go to autozone and get a product called evapo-rust. this is a really neat product that doesn't harm rubber or plastic(in most cases). You will fill through the hoses the heater core and radiator. Now let them sit for about 4 hours, then use a hose again through the upper hose of the radiator and the the cooler hose of the heat core and continue to run the hose till you get clean water out. repeat this procedure again until once you put the evapo rust in and it immediately comes out clean after sitting. You may want to let it sit over night. On a few cars it has taken me a full two days for flushing every few hours with over night sits to get them to clean up. i had chunks of shit coming out of the heater core. The evapo-rust will break this stuff up. Normally the block come clean after a good hose flushing. once you get clean water out of everything then do one of those run it with a chemical cleaners drain it out and refill with the yellow coolant. also wash out the overflow bottle real well.

[JoeliusZ28]

when i do coolant flushes I just start the car and open the radiator drain (with an appropriate catch bucket obviously), then I just run the garden hose directly into the radiator. I keep filling it with water until what is coming out of the drain is perfectly clear. Then I shut the car off and fill it with the proper mixture.

Once most of the green/coolant is out, you can get rid of the bucket and just let it drain on the ground too if you wanna give it a really good flush.

[00firebird]

when i do coolant flushes I just start the car and open the radiator drain (with an appropriate catch bucket obviously), then I just run the garden hose directly into the radiator. I keep filling it with water until what is coming out of the drain is perfectly clear. Then I shut the car off and fill it with the proper mixture.

Once most of the green/coolant is out, you can get rid of the bucket and just let it drain on the ground too if you wanna give it a really good flush.

when do you run the engine, during the whole process? also wheres the radiator drain at, bottom side? and the top side would be where it says "do not open" where you put the hose in?

[DETROITMUSCLE]

yep garden hose goes in the top of the radiator. Hes probably referring to draining out the petcock valve on the bottom of the radiator.

[JoeliusZ28]

when do you run the engine, during the whole process? also wheres the radiator drain at, bottom side? and the top side would be where it says "do not open" where you put the hose in?

correct. its probably best to have 2 people to not make a mess and monitor the gauges. But the engine can be running as long as there is coolant in the system. You want it running as the drain is open and the hose is in the cap (the one that says do not open). That way your engines water pump is drawing in the fresh clean water and pumping the old shit out the drain.

do not run the engine without coolant and keep an eye on your temp just in case. ive never had a problem doing it this way, and you see some nasty crap come out usually.

[00firebird]

sounds good, what if gunk is in the heater core?

[JoeliusZ28]

you cross your fingers this flushes it out? lol ... idk. let it run through for a while if you think its bad.

[bri2203]

Coolant is the most neglected fluid in a car. I do not know anyone who changes every 5 years (with the green stuff 2 years.)

If it were me I will drain the radiator via the pet ****, pull a knock sensor(I believe the knock sensor is hard to get to on the passenger side, I only did one) and that will drain most of the the system. Then refill with yellow coolant that can be mixed with dexcool/green stuff. Then I would recommend drain the radiator a few months later

[bri2203]

sounds good, what if gunk is in the heater core?

radiator shops will used water and compressed air to clean heater cores or you could replace the heater core. lol

CHANGE YOUR COOLANT PEOPLE!!!


JOER, I like the new sig! It took me a minute to put it together than i saw the "C"