I’ve had this system installed and in use since June 2012 —- love it! However, ‘bout a month ago, I noticed strange odors in the car. This was just after topping off the gas tank, refilling the reservoir and accidentally over-filling it. No mess inside, just a slight puddle on the concrete floor (stored in a closed garage). Thought the odors were from the overfill, so I put a few fun miles on it to lower the fluid level slightly. Windows down and sunroof open —- cleared it out nicely. Just to be safe, I decided to keep the windows down and sunroof open while in the garage. Due to our self-isolation practices, we don’t drive anywhere much any more, so car usage is minimal, and we’re a two-car family.


So, yesterday I made a pizza run with the Mini and noticed the WMI liquid level alarm light was on. This was with only about 100 miles on the tank of gas, and there should have been at least two quarts of WMI mix in the reservoir. Conclusion —- WMI leak! Odors must have evaporated thru the open windows and sunroof, into a 2 ½ car drafty garage.


Un-bolted the reservoir this AM and found one of the two hose connections on the bottom of the tank was wet. All the other hoses were in good condition —- no noticeable wear and felt like a good tight fit on the barbs. Turns out the nut holding it together was only finger-tight, both bottom-of-the-tank hoses. Tightened them up with a wrench, refilled the tank, let it settle for a few minutes, and no more wet fitting. Didn’t check the washer but it feels like soft felt that just needed to be compressed. If the leak continues, I’ll try replacing the washers.


Main reason for posting this is, I want to warn other HFS4 owners. If you’re on a long trip, in bad weather, have family on-board, you don’t want this scenario —- these fumes are toxic so check these fittings! It’s an extremely easy task. I have 50 - 60K miles and 8+ years on my system. Haven’t heard of any other reports like this, so maybe it’s just a one-off happening, my Mini has more than its share of vibrations. But since I consider it a safety issue, I want others to know about it. Under no circumstances do I consider this a manufacturers defect —- too many years and trouble-free miles with a highly modified engine.