I put the car on my lift to do an oil change the other day. I carefully checked the whole bottom of the car from front to back. Not a single drop of ANYTHING under there!! The good news is that I have not smelled it since I posted the above thread. It is sooooo random. I just had a thought though. Is it possible that the antifreeze recovery tank (if there is one), has a hose attached to the vent that vents it to the bottom of the car towards the rear of the engine? I can see them doing this in case it over flows, so it doesn't dirty the engine compartment. If they do have the hose, maybe we can smell it a little as the level in the tank rises? I know it's a far reach, but it's weird for me to intermittently smell antifreeze and not even lose a drop!

 

I think you are correct in your assessment that the oder is from overflow. I haven't experienced the "antifreeze odor" but in trying to help someone with another problem I took the cover off and looked at the radiator arrangement. If you look, you will see that there is no antifreeze recovery tank that was common on older designs. The coolant reservoir that was the top of the radiator in older designs is a nylon tank on these cars and the overflow hose is a short hose, about 6" long, that goes down the back of the tank and allows the overflow to go into the front of the engine compartment. I don't see that as a problem, except that antifreeze has a very distinct odor and even a few drops can be easily sensed by most people. Whenever liquid - antifreeze or water - is added there will be some overflow until equilibrium is reached. And, a very important point in all this is the cap on the coolant reservoir. The cap is a pressurization cap, much like the old radiator caps and must be properly tightened or pressurization will not be attained and there will be overflow because the boiling point of the coolant will be lower. To properly tighten the cap, you must turn until it clicks, much like the pressurization cap on your fuel tank.

 

I have a 2007 LS460-L with the same intermittent coolant odors. Quickly appears then disappears... This post was helpful-thank you.

Any other developments? Discoveries?

Cheers,

 

You probably got the car hot and a little bit of coolant flowed out of the overflow tube and blew onto the exhaust manifold while you were driving. When you parked the car, the little bit that was on the exhaust burnt off...leading to the smell. I've smelt it on my car before...checked the level...no problems. It has happened to me a couple times, but nothing major.

That's my guess.

 

I wonder how many miles are on the original poster's car now?

That's crazy to have such low miles after that many years, unless you can afford to buy a brand new LS and just forget about it!

 

3,500 miles on an 08? HUH?? that's kind of scary.

 

And I thought I didn't put much mileage on my car!

 

Hi guys,
I'm the original poster. I got a notice in my e-mail that there was activity on this thread so I logged on. I sold the car back in 2014, I think I had about 5,000 miles +/- LOL. The car was unbelievably immaculate when I sold it. I sold it because I wanted something a little more fun for zipping around town and running errands since I didn't take too many highway trips (where this car excelled) so I purchased a Porsche 911 Turbo.
I can tell you that the weird smell seemed to have stopped since my original post. I sold the car to a gentleman that I still keep in touch with! He was a great guy and also a car nut, so we got along great. As far as I know, He has 25,000 miles on it now and has zero complaints. He absolutely loves the car! Sorry I couldn't be of more assistance, but I didn't want to leave loose ends on this thread.

 

You're a good man for following up! Thank you for that.

 

Wow...couldn't agree more!

 

Another possibility is a leaking water pump. Mine was leaking, but left no evidence anywhere in or under the engine compartment. It wasn't until I removed several engine compartment covers and looked closer that I saw the failing pump as evidenced by the crusty pink cluster at the weep hole.

 

Chris. You're a gentleman for the follow up. So very much appreciated.

Cheers,
-Adam

Ps. 911 Turbo sucks little

 

Adam,
Thanks. Lol
Well, I already got rid of the 911 turbo as well, LMAO. I have automotive ADD.