Propane smell inside 2010 Prius

After my 2010 Prius sat unused for about 10 days, the interior smelled heavily of propane. I understand that propane is colorless and odorless and that it only smells due to the ethyl mercaptan added to it. There is no propane in the Prius (I did call my dealer and they verified no propane and they had never heard of such a thing). I smelled the hybrid battery vent on the passenger side of the back seat and it does not seem to be originating from there. Could something in the car be deteriorating that would create ethyl mercaptan or a smell like it? After using the car since, I still smell this but not as strong. Any comments would be appreciated.

 

Tomorrow I will look for something dead or food and will also dive into both batteries to see if they seem to be venting - definitely a propane smell - not rotten egg smell. Will report back after my deep dive...

 

Will check cabin filter and under the hood. No kids - just me - so pretty sure it is not food.

 

I have not yet located the propane smell but I have caused myself Considerable Trouble while learning some things in the process. While systematically going through my car and removing and smelling every thing, I exposed (for the first time) the back side of the hybrid battery case. The orange plastic plug on the right side had a handle on it so I pulled it and removed it to look at it, and then put it back. The 12 volt battery looks good and clean and its vent is in place and functioning and does not smell. I ran out of time to go further since I had to go to work. Much to my surprise and dismay, the car started but would not go into reverse or drive and I had a large "Check Hybrid System" on the dash display. I had no time to go back in the house to search PriusChat so borrowed another rig to get to work. Later research showed me that I had not completely replaced the orange plug (it needs a slide to the right to fully lock it in place) and that the orange plug disables the hybrid system (one person said it would be a good theft deterrent - I agree!). So I properly replaced the plug and the car did start and go except I still had the "Check Hybrid System" on the display along with the large triangle with an exclamation point that would not go away. Back into the house to dial up PriusChat - the advice to start and stop the car three times in a row did the trick and the displays cleared. Next is further exploration of the hybrid battery area and the battery fan. Stay tuned. And thanks for being such a good resource for us uncertain DIYers!

 

Update on Propane Smell in 2010 Prius with a deep dive search and smell into almost everything without discovering the source! Searched/smelled (s/s) under hood, s/s interior, all items in car, under seats, removed glove compartment and cabin filter (cleaned not that long ago and still clean), s/s and removed everything from rear hatch including spare tire and tools and warm clothes and emergency stuff, 12 volt battery clean with no corrosion and vent tube intact, exposed hybrid battery fan and cleaned it (not dirty at all) , removed/cleaned the air vent to the hybrid battery (passenger side of back seat) as well as the black plastic vent from the battery, removed metal cover for the hybrid battery (after disabling it with orange plug), very little corrosion on hybrid battery metals (decided not to use anything other than an old toothbrush - nothing to speak of brushed off - felt too risky to use boric acid or vinegar or baking soda, etc under the "if it ain't broke, don't fix it" rule), verified that the rubber venting tubes running along the top of the cells were clear and venting through tubing to the exterior of the car. I did this over the course of several days and the propane smell lightly persisted. Got it all put back (nothing left over) and then jacked up the car 5 different ways to get underneath to smell and search for anything dead or melted or stuck underneath. The smell clears upon use and does not seem to be coming through the fresh air vents but I am considering borrowing a leaf blower and forcing air through the fresh air vents without the car running to verify nothing stinks in there, My only other thought is something could be under the plastic panels on the bottom of the car. I would want to have use of a lift to undo all that...

After much searching on the Internet, I found cases of GM vehicles that had a propane smell coming from the transaxle and it was solved by venting it more towards the back of the vehicle.

I wanted to give an update as it drives me nuts when someone posts about the same problem I am having and then never gives us the rest of the story...any comments or other ideas appreciated.

 

No odor anyplace that I delved into, including around the hybrid battery. No kids but I like your seat idea. I did not remove the backseat previously but looks easy to do - will do so and report back.