Though it sounds intimidating and labor-intensive to folks that haven’t tackled this project, draining coolant from your engine block is pretty simple and straightforward.
In fact, almost anyone can pull this project off in their driveway – all without ever having to visit a garage, have a lot of mechanical know-how under their belt, or even own a lot of tools!
Sure, you need to be deliberate about how you go through this project if you are going to attempt it. The last thing you want to do is mess up the coolant system responsible for keeping engine temperatures safe and stable.
But armed with the inside information in this quick guide you should have no trouble whatsoever figuring out how to drain coolant from your engine in record time!
Do I Need to Change My Coolant?
Unlike motor oil (which should be flushed and changed every 3000 to 5000 miles) you probably aren’t going to have to swap out your engine coolant anywhere near as often.
In fact, there are some engine coolant varieties on the market today that are designed to last between 130,000 miles and 150,000 miles before having to be flushed and replaced.
This is the kind of project you might only have to pull off once with every vehicle that you own!
At the same time, it is important that you make sure that your coolant is replaced when it starts to get dirty, when it starts to fill up with sediment, or when it starts to smell kind of burnt.
Those are obvious signs that the coolant is no longer as effective as it was before and it’s time to start over with something fresh.
How To Drain Coolant from Engine Block
All right, now that we’ve gone over the importance of making sure that you flush your coolant when necessary let’s get into the meat and potatoes of actually undertaking this project.
Make Sure Your Engine is Cold
The very first thing you need to do when you are getting ready to flush your coolant is to make sure that you are working with an ice cold engine.
No, you don’t have to tackle this project only in the winter when temperatures dip below freezing. But you do need to make sure that you haven’t run your vehicle for at least a few hours before you start messing around with your coolant.
Every time you fire your vehicle up coolant go searching through the engine, pulling heat from the internal combustion components, and then working through the radiator to exchange that heat outside of the vehicle.
When you turn the car off the coolant doesn’t go ice cold right away.
In fact, it stays pretty hot – and under pressure – for quite a while. We are talking a couple of hours (minimum).
If you opened your radiator cap right after going for a cruise around town or running errands you’d be blasted with steaming hot coolant under extreme pressure.
Not ideal.
Make sure that you haven’t driven (or even idled) your vehicle for at least a few hours before you start this project.
Spot the Drain Plugs on Your Engine
The next thing you need to do is find the actual drain plugs for your coolant system located on the engine itself.
Drain plugs on most modern vehicles are almost always going to be located somewhere towards the back of the engine block, either on the bottom of the block itself or pretty close to it.
The plugs themselves usually won’t be located right next to the oil plug (or even anywhere near the oil pan), but somewhere in the vicinity. It’s not a bad idea to start your search for the plugs at the flywheel housing.
Once you spot bolts in the back of your engine block that don’t appear to be holding anything in (or anything together) you’ve found your coolant plugs.
You can also find them pretty quick by googling engine bay diagnostics or looking for them in a service manual.
Position Your Drain Pan
Now that you know where your drain plugs are you can position your drain pan to capture all of the coolant to be discarded.
Just wiggle that into position and you’re ready for the next step.
Slowly Back Out the Bolt, Let the Fluid Drain
When it comes time to back out your drain plugs you are going to want to make sure that you go really slow and are really deliberate.
You don’t want to just ratchet them off like you are in the pit at a NASCAR race. That’s going to send fluid spilling out all over the place and send your bolts flying with it.
By backing things out slowly you can control the flow of fluid pretty effortlessly. Keep backing these plugs out until the coolant system runs bone dry.
Tighten (or Replace) Your Bolts
After the coolant has been completely drained from your vehicle you can replace the bolts into their position.
It’s not a bad idea to check out how much these bolts should be torqued according to the manufacturer, either.
You never want to spend them on to hard (potentially cracking something or making them impossible to remove later on), but you don’t want to put them on to gingerly so that they spin off later on their own.
Torque them down to spec and you’ll be good to go.
Refill Your Coolant
After you have confirmed that your drain bolts are back in place you can refill your coolant up to the “cold fill line”.
Make sure that you go by the cold fill line and not the “warm fill line”.
Run up to that second maximum fill line intended for hot overflow coolant and you’ll end up overfilling the reservoir and spilling coolant out all over the ground.
Run Your Engine – With the Radiator Cap Off! – For 30 Seconds
A lot of automotive experts recommend that you run your engine on idle for about 30 seconds or so with the radiator cap off of the vehicle, just to make sure that the system gets pressurized correctly.
You don’t want to go to long here, but 30 seconds to a minute of idling with the radiator cap off isn’t going to do any harm.
Reattach Cap and You’re Good to Go!
All that’s really left to do now is to reattach the radiator cap and check for any leaks.
If everything looks all good and bone dry you are all set!