Well its been years since I posted here, not that I didn't want to, but we had the dealer do all PM's on our 2018 Highlander with 67K miles. Well because of economics, we can't afford to pay the dealer and buy food, as most of us have experienced in the last couple of years. So I changed out the coolant before the 100K mile interval due to issues with head gasket failures on the Toyota engines that went 100K plus miles on the original coolant. I know its arguable about the early interval, but I believe the source that states its better to change coolant early. The opinion is that the old coolant turns acidic and eats at the coating on the metal head gasket, which can cause a possible head gasket failure and overheating that can warp the block, as well as the heads, and that is not machinable and requires a block replacement.
I spent 4 hrs looking for the petcock valve on the block, to drain the coolant from the block, and had to put everything back together so my wife could get to her appointment. Then another 2 hrs after taking the lower engine guard, I won't call it a skid plate being flimsy plastic, and air filter housing. So I searched youtube and went to the parts house where I bought the coolant, with no luck finding that information. I did find a video on a 2GR-FKS, but in a Lexus where he had pictures of the block petcock valve. Now that I could identify it when I saw it, I looked in the rear of the block (Driver Side) and finally found it. SO if someone does a search here on a highlander coolant replacement they may find this post. This link can help alot, but it is a Lexus.
This is the Video that put me on the right track.
So remove the guard cover (skid plate) under the drivers side to access the rear view of the engine, and you'll see the same petcock valve as the video I linked here. A long wobble 1/4" extension and a 10mm socket works well. Also in the video he uses a special funnel that I bought as well, that worked awesome in helping to get the air out of the system, at $34.00 from Harbor Freight, it made it so easy and kept the spilling at a minimum. Unfortunately I didn't take any photos, but after 6 hrs in two days looking for that petcock valve, I wanted it over with.
I hope this helps someone here that plans on the same DIY coolant change on their Highlander.
I spent 4 hrs looking for the petcock valve on the block, to drain the coolant from the block, and had to put everything back together so my wife could get to her appointment. Then another 2 hrs after taking the lower engine guard, I won't call it a skid plate being flimsy plastic, and air filter housing. So I searched youtube and went to the parts house where I bought the coolant, with no luck finding that information. I did find a video on a 2GR-FKS, but in a Lexus where he had pictures of the block petcock valve. Now that I could identify it when I saw it, I looked in the rear of the block (Driver Side) and finally found it. SO if someone does a search here on a highlander coolant replacement they may find this post. This link can help alot, but it is a Lexus.
So remove the guard cover (skid plate) under the drivers side to access the rear view of the engine, and you'll see the same petcock valve as the video I linked here. A long wobble 1/4" extension and a 10mm socket works well. Also in the video he uses a special funnel that I bought as well, that worked awesome in helping to get the air out of the system, at $34.00 from Harbor Freight, it made it so easy and kept the spilling at a minimum. Unfortunately I didn't take any photos, but after 6 hrs in two days looking for that petcock valve, I wanted it over with.
I hope this helps someone here that plans on the same DIY coolant change on their Highlander.
