Coolant boil over after care


Feb 17, 2023
2012 Jetta CJAA
Hello guys,
Checking in after an unfortunate self inflicted wound. I had to run a standing regen for issues unrelated and like an idiot I forgot to remove the winter front blocking my entire grill because I have a stuck open thermostat being replaced this week.

anyway, during this process I saw the steam under hood and realized my folly immediately shutting the CJAA down. Coolant reservoir lost its top (loose) and boiled over at about 224 degrees when I checked. I promptly refilled with pentofrost I had on hand and lost about 1 1/4 gallons. The coolant was back down to normal temps within 10 minutes or so.

i later started it back up and doesn’t seem to act any differently than before. Are there any health checks you guys would recommend after a brief overheat?


Veteran Member
Sep 3, 2012
Mk6 Wagon
If it was quick, you shouldnt have any issues, especially if it didnt actually pin the temp gauge. Now that being said, no one can tell for sure if you wont have issues down the road. I would just keep an eye on the coolant bottle because one sure way to tell is if you have pressure in the bottle when its cold. If the temps are back to normal and the level is fine, I'd say just keep an eye on it. Steam under the hood was most likely the spilled over coolant touching the engine or other hot components. It usually gets to around 600C while doing a regen up front.