Why Your Car Needs a Fluid Exchange: Keeping Your Engine Cool and Healthy

Dear Mike,

I recently took my car in for maintenance and was told that I need an engine and cooling system fluid exchange or a coolant flush. I’m not exactly sure what this means or why it’s necessary. Can you explain what these services entail and why they are important for the health of my car?


Dear Sadie,

Thank you for your inquiry. A fluid flush or fluid exchange is an essential part of any car’s maintenance routine. Simply put, this service replaces the old fluid in your car’s engine and cooling system with fresh coolant. But why is this important? Well, let me dive into the nitty-gritty details.

Your car’s engine gets hot, and I don’t mean Netflix-and-chill hot, I mean bake-a-cake-on-the-hood hot. In fact, your engine can heat up to over 200 degrees on any given day. This can cause individual parts in your engine to overheat and break down. That’s where the cooling system comes in – it keeps your engine at a manageable temperature so the parts inside don’t overheat, and as you so aptly put it ‘bite the dust’.

Think of your engine as a chicken car, but instead of a refrigeration truck, it’s running around the yard looking for shade to avoid being cooked. Your engine is the chicken and the cooling system is the refrigeration truck. Yes, it’s a weird analogy, but it will help you understand the importance of this particular service.

Now, back to coolant fluid. This is the stuff that moves within your engine to keep it cool. It’s a complex system that involves your radiator, reservoirs, fans, hoses, and of course, the coolant.

When all these things work together, they keep your engine at a reasonable temperature. But, as with all good things, the coolant wears out, becomes dirty, and loses its effectiveness. This is where the fluid exchange service comes in.

Depending on your vehicle, you need to exchange your fluid every 100,000-150,000km, or every 5 years, whichever comes first. However, it’s not just about timing. There are also symptoms to watch out for, like your engine overheating, your temperature gauge jumping, your car feeling sluggish, or a Check Engine Light or Low Coolant Light turning on.

In addition, leaks in your coolant system can cause a low coolant level, which is another thing to watch out for. The hoses that carry the coolant throughout your engine can become old and worn, leading to potential leaks.

So, what does the fluid exchange service entail? Well, most service providers and dealers simply remove the lower radiator hose and drain the system of coolant. Some may or may not add a chemical cleaner prior to emptying out the system. If they do not add pressurized water through the cooling system and radiator, not all of the potential deposits within the system are being removed.

That’s why the coolant fluid exchange process, using a machine, is the better option. It removes all the old fluid in your cooling system and replaces it with fresh new fluid. So, be sure to ask your service provider or dealer if they’re performing this service with a coolant fluid exchange machine to ensure the job is done right.

So, there you have it Sadie, my long-winded explanation of why a fluid exchange or flush is important for the health of your car. Don’t ignore the symptoms and get this service done when it’s due. Your car (and wallet) will thank you.

Best regards,

Mike Urban, Founder of Urban Automotive