Coolant gunk/sludge

[crow]

My mechanic says there isn’t a way to remove the gunk in my cooling system, and that the radiator, water pump, heater core, and thermostat must be replaced.

The gunk seems to be DexCool oxidation residue. Assuming it’s DexCool gunk, is there, despite what my mechanic says, a way to clean it out?

 

[Tormach]

What year and engine do you have? How many miles on the car?

Where you losing coolant from a slow leak you could not find/lock down?

If it was low on coolant did you add any? Did a shop add coolant to the system when getting an oil change? If coolant was added, was it Dexcool or was it another type?

Problem with GM's Dexcool (OAT based) is it will gunk up if air is in the system to long or if you add a non-dexcool to it (say the green - ethylene glycol), it will eventually gunk up and block the jackets/heater core/damage water pump/etc...

 

[crow]

Let me sharpen my question.

The coolant system is gunked up. Assume DexCool gunked it. Any way to clear the gunk?

 

[Tormach]

Don't Rush the Flush

You could try any of the options from that link or find GM's coolant flush procedures.

I personally have not experienced the 'gunk' issue and do not know what is the best way to tackle it.

I can say this, that is a lot of parts to replace.. especially the heater core, which means that is going to cost a perty penny.


Hopefully someone else can chime in that might know a trick/way to do it or what chemicals will work that wont damage your system in the long run.

 

[wr_guy]

Forget how it got there.
If it is not leaking.
Just flush it a couple of times and replace it and see what happens.

dexcool is fine if you replace it every 4/5 years like you are supposed to.

 

[gothstone]

Just did an Aveo that was FILLED with jelly from somone mixing coolants before I got it. Use Prestone radiator flush and oil degreaser, not just their regular flush. Follow their directions mostly. good couple hours on the cleaning run. Don't wait for the engine to cool every time, the water won't get as hot as you would think and it wastes a lot of time. Repeat the fill with water, run for a while, then drain cycle until what your draining has NO bubbles left in it. Pick up at least 10 gallons of distilled water. Once your draining clear with no bubbles, put in a measured amount of half the coolant capacity of prestone dexcool concentrate. So 3.15 qts on a 2012 1.8L, look yours up if different engine. Then top off with distilled till it's actually full with no more air bubbles.