Dirty coolant

I've just noticed that my coolant is dirty , it was clear when I first put it in , no sign of mayonnaise on oil cap or dipstick , should I just drain, flush and refill and see what happens , doesn't look rusty , just looks like muddy water , no oil floating on top , no performance / overheating issues .

Neilcmusic1 wrote: ↑Sun Aug 02, 2020 1:13 pm I've just noticed that my coolant is dirty , it was clear when I first put it in , no sign of mayonnaise on oil cap or dipstick , should I just drain, flush and refill and see what happens , doesn't look rusty , just looks like muddy water , no oil floating on top , no performance / overheating issues .

Hi

I would say yes, back flush it with a hose pipe until it runs clear.

That way you will know that all old coolant and contaminants are out.

Then drain as much of the water out and refill with the pink OAT coolant.


The problem you may find eventually with bad coolant that it's corrosive and generating contaminants that affects the weakest part of the chain and that is the head gasket. Hopefully you have caught it in time and with no symptoms, you probably have.

Neilcmusic1 wrote: ↑Sun Aug 02, 2020 1:13 pm I've just noticed that my coolant is dirty , it was clear when I first put it in , no sign of mayonnaise on oil cap or dipstick , should I just drain, flush and refill and see what happens , doesn't look rusty , just looks like muddy water , no oil floating on top , no performance / overheating issues .

You didn't say when/why/you changed the coolant. Was it dirty before? Have you owned the car since new? How long ago did you change the coolant I.E. how long did it take to become dirty?

If your car is second hand, don't be too surprised, most people don't maintain their cars properly. The best you can do is attempt to arrest any corrosion that has formed.

If you have owned the car since new the type/strength of the inhibitor you are using is not doing the job.

I have not found that the coolant quality has anything to do with head gasket failures but not looking after the coolant wont help. Having said that, there are other areas of the engine that will suffer from poor quality coolant.

I would recommend flushing and refilling with de-mineralized water then running your car for a couple of weeks. If impurities come back, keep changing the water. The system will eventually come clean. Buy the de-mineralized water from a super market, not an auto store they rip you off. De-mineralized water is harmless to the environment and is cheap.

When it comes to choosing a coolant mix here are some FACTS:

Fact: If the ambient temperature that your car will be subjected to does not fall below 4' Celsius, you do NOT need anti freeze. To err on the side of caution you might raise that number a few degrees?
Fact: All "100% coolant" additives contain 95% ethylene glycol or Polyethylene glycol (anti freeze).
Fact: Premixed coolants rarely contain the minimum recommended ethylene glycol to water ratio(1/3) for antifreeze protection. Don't believe me? Read the label! It needs to contain no less than 330g/litre ethylene glycol (as an anti-freeze). That's very expensive water you are paying for.
Fact: LESS than 2.5% of the "coolant" (not just water) in your engine is active corrosion inhibitor. Typically in a 50:50 mix you are looking at 50% water 47.5% ethylene glycol and 2.5% inhibitor. So once again you are paying X amount over and above any other "coolant" for just 2.5% of the content of your cooling system, considering ALL contain the balance in glycol. So if the label says "X technology inhibitor" that is about 5%, or less, of what is in the container, for which you are paying a premium. Just saying.
Fact: Water is superior to Ethylene glycol as a cooling agent.
Fact: Inhibitors are added to glycol based coolants because glycol is not a good corrosion inhibitor when used in heat transfer applications.
Fact: Ethylene glycol is extremely poisonous to humans and the environment. Polyethylene glycol is not but it's very hard to find.

If it wont say what's inside the container, go on line and look up the MSDS sheets.

Opinion: What is put in your cars cooing system from the factory is a guess from the manufacturer to "cover all bases". They don't know where or how your car is going to be used. Even here in Australia in the high country it can get below freezing. Is it the best? As far as they are concerned, it's the best to cover all bases.

I am NOT saying don't buy glycol based coolant additives if the ambient temp stays above 4'. Glycol wont hurt your car. Just be aware of the facts and what you are paying for. Sometimes an "inhibitor only" solution is just not findable. Perhaps you can do your research and come up with a better, cheaper and more environmentally friendly alternative?