Was wondering if anyone tried using those coolant machines to flush their system out block and heater core. As I believe my my heater core is blocked because i noticed that my coolant look rusty in color.

 

heater core is aluminum... so its not the source of your rust.

its either from the block or the coolant pipe that runs the back side of the motor.

 

Unless stopleak has been put in the cooling system I doubt the heater core is plugged. Maybe a new thermostat - and change the coolant.

 

I had the same problem but no heat from the vents. I replaced the TS, Flashed the system with water(High pressure) and put Mitsubishi coolant and fixed the problem. NOW I am not say use only Mitsubishi coolant, use what every you like just green color or blue.

Good Luck

 

Here's the way I like to flush coolant on the Evo. First, I buy about 4 or 5 gallons of distilled water. Drain petcock on the bottom of the radiator. You'll only get 1/3 to 1/2 of the coolant out. Tighten petcock, fill radiator with distilled water. Start engine or drive around for a few minutes until thermostat opens. Drain coolant, fill with more distilled water, and repeat this process 3 or 4 times until you have almost pure distilled water coming out of the system. Then top off with 50% of the total system capacity with concentrated coolant (I recall was about 3/4 of a gallon). This will give you nearly perfect 50/50 mixture. As long as you use the proper amount of concentrated coolant, you can top off with distilled water and have the perfect mixture.

Here's why I like this method ... engine seals, water pump impellers, etc are very sensitive to minerals in tap water. Yes, you will waste some distilled water with this method, but it's cheap, and you'll be guaranteed to have only distilled water in the system before you top up with coolant concentrate. Also, make sure you know what you're doing when choosing 'regular', off the shelf coolants (I like the OEM coolant). I read that that Japanese cars in particular recommend coolants with specific formulations ... that their heater cores, water pumps, seals, etc are designed with these formulations in mind. Off the shelf 'safe for all' coolants may not have all these ingredients. Basically, the OE coolant is pretty cheap so I just use a gallon of that to be on the safe side. I've been using this method every 30K miles, and I've never had a cooling system failure, and my coolant reservoir is clean as can be at 150K miles.

 

This is an older article, but the takeaway here is there are alot of coolant specification differences between manufacturers. I work in the industry, and in all honesty, I'm not 100% sure if there is an aftermarket, parts-store coolant that meets the OE specs. To be on the safe side, just use the OE coolant, which is about $20 for a gallon and can buy online easily.

https://www.motor.com/magazine-summa...-or-orange-or/

 

no one here uses zerex asian vehicle? it's red in color, idk how much the color matters but the coolant is good quality

 

No, never heard of that.. Prestone here...

 

I'm sure OEM coolants are superior, they're made for long life. However, anytime I need to drain the cooling system I replace the coolant with new. Replaced the radiator, new coolant. Pulled the radiator to replace the transmission, new coolant. Decided to replace all the cooling hoses, new coolant. Replaced the thermostat, new coolant. So, for the average Evo owner who likes to tinker on his or her car, I don't see the need for expensive coolant. Walmart for me.

 

Pretty much sums it up!