Stilo 2.4 & JTD Thermostat Replacement

You're ready to put some coolant back in it now! If you've bought ready-mixed stuff get pouring it in, otherwise you'll have to make yours up from concentrate.

Follow the guidance on the bottle for concentration levels. The stuff I had was 25% for normal use.

Pour it in, you might as well over fill it a little as you're going to get some air come up. I filled mine up to about 3/4 way up the bottle which turned out to be about right.

Make sure you screw the cap back on the coolant reservoir.

If you removed any induction piping, as I did, refit it now and start the car. Don't be alarmed that it starts to steam and smell funny as it gets hot, as obviously we've sloshed some coolant around that'll evaporate off.

It's important that you let the car run up to temperature, i.e. the middle mark on the temp gauge, so you get coolant flowing through the entire system. So crank the stereo and relax for a few mins.

Make sure the car runs up to normal operating temperature. When it gets there, whack the heaters on full for a few minutes. This will make sure you've got no air in the heat exchange.

The coolant level will drop as the air gets shifted but shouldnt drop far enough to empty the tank. If the tank empties stop, check for leaks and refill when cooled and repeat.

As you're getting up to temperature make sure you're not leaking anywhere. Also check that none of the pipes are starting to try and pop off the stat, just in case!

Don't add coolant to a hot system, if you do need to add more let the car cool and add when cool.

Essentially, you're done. Any remaining trim pieces not yet refitted do so and you're golden!

Keep and eye on coolant levels over the next few journeys as it may shift a few more air bubbles but it shouldn't decrease significantly. Again, if it does, inspect for leaks.