Hi all...I've searched on this and so far it does not seem to be covered...so here goes:

Shortly after joining the new engine club, I started noticing a slight coolant odor when stopping the car. Time went on and it actually vanished, returned, then really starting showing up even when the car was moving. Took it in to the dealer, and sure enough they found that the tank had a small crack (presumeably started microscopic, but started growing to the point the odor was always present). Had that replaced under warranty and just started to notice a similar odor today after a hard run through the city.

So, after examining everything and seeing the levels were perfect...I happened to notice the small black hose that is inverted near the rad. cap on the expansion tank. This hose is not in a closed circuit, but rather just a few inches long and completely open. There does not appear to be much in the way of loss, but having a "vented" expansion tank would definitely account for the odor.

Can anyone out there confirm if this is the way it is supposed to be, or should there be a closed circuit on this? I mean, having coolant odor as normal operation seems very odd to me, and is going to be unavoidable at time of heavy running by the way my expansion tank is set up.

 

That hose is not to be connected it's an overflow for the tank. Was it a hot day?

 

For Austin, TX it was actually mild, about 80F.

The only other thing I can think of, barring an actual slow leak (which seems unlikely due to the consistent level since replacement) would be that the prior tank's spill may have left some residual coolant behind and until located and cleaned may be heating up and causing the odor.

 

It could be you push it a little harder and a little coolant came out. As long as the level stays good you should be fine.

 

coolant expands when heated. the hose is there so when it has too much pressure, the expanded coolant* will not be all over the place.

but the hose is positioned @ a very bad location, the coolant will spill right into the power Steering wheel connector.

After a while, it might clog the connector and ur power steering might fail.

either replace the hose and direct it to somewhere to bottom of the car, or clean that air with clean water once in a while, or just cut the connector and hard wire it(not recommend if u're under warranty)