Flush coolant with baking soda.

[oil pan 4]

I have herd that a cheap way of cleaning out a cooling system is two put about half a box of baking soda in the car and run the motor untill it gets up to temp, then drain the system and flush it again with water.
Would that work?
Alot of other flushes contain weak acids.
At least baking soda would get rid of any acid in the system.

 

[UncleS2]

That's a new one to me.

I wouldn't try it in my car. Why?
One reason is because it's virtually *impossible* to drain all the coolant out, so there would always be a little baking soda left behind.

Another reason: baking soda is a base(as opposed to an acid. Lye is a *strong* base). Did you ever see what happens when aluminum comes in contact with a strong lye solution?

When I was a kid Dad filled balloons with...but that's another story!

Any aluminum in your cooling system(in my case, the head, intake manifold, & radiator!) might not be harmed at all by traces of leftover baking soda, but I wouldn't want to take the chance. It would be in there a long time at a high temperature. I may be wrong, but it sounds like asking for trouble to me.

Unless you have good reason to think your cooling system is really gunky, just drain, fill with clean water, run till warm, drain again. Do it several times if you like, or think it's needed.

If want to use a flushing agent, it might be safer to pay a few $$ for a purpose made product that's guaranteed safe for your cooling system.

 

[Big Jim]

This was a common method three or four decades ago. Baking soda is near neutral and is often used to buffer either acids or bases.

I have not ever tried this with a car that has so much aluminum, but I have done it many times with iron engines and brass radiators.

It was also commonly used to flush a cooling system when it had been flushed with acid cleaners that left an acid odor that just would not go away.

Washing soda was also once commonly used for this.

I agree that I would not try this on aluminum components, but I don't know one way or the other if it would work or not.

Today, I change the coolant often enough that it is not necessary to do a flush. I think that is the best answer.

 

[Vilan]

Coolant is normally basic. They add a little potassium hydroxide or somesuch. The coolant info sheets I've seen show a pH from 9 to 11 depending on the brand (water is 7, acids below 7, bases above 7). Baking soda is a weak base, I don't see how it would be a problem.

Whether it would actually be *helpful* is another question though.

I say flushing with plain water is fine as general maintenance, unless you have a specific problem you're trying to fix. The water will also flush out any acids. Just flush a little longer if you're worried about it.

 

[oil pan 4]

When I do flush the system on my cars I normaly unhook the hose going to the heater core and put a garden hose on the end of it. And push water through the heater core under pressure back into the engine and out through where the line was connected to the pump.
While it's running and hot, well hot when I start it. The engines tend to cool off kind of fast with cool water going through them.
I think the pH of baking soda is 10.4
The next car I might do this to would be my 1985 Z28. But the coolant is only about 2 years old, I flushed it real good 3 times with different brands flushes then it sat for about 18 months.