Today was the first time I've driven since I smelled the coolant. I took maybe a half a cup out the day I smelled it. I noticed no problems at all. The car warmed up a bit slower than usual but it was in the low 30's! No coolant smell at all and I made sure that the recirculate air was off. I can't explain it and I hate mysteries. I'm certain that something is hinky. I couldn't find anything; let's hope if I do I'm not on an interstate. I'll be popping the hood at every stop.

 

Our '05 S-Type 4.2 had a slight leak at the vent line connection on the reservoir that did not show itself unless I moved it slightly allowing a visible stream of steam to escape. The first indication was the low coolant message. Ultimately, I did see some orange residue below the connection, which prompted me to start probing. The hose is fairly soft and the hose clamp was just beginning to lose its grip.

 

you need to really watch this cause that is right where the reservoir cracks. That line breaks off and pumps coolant out while driving, of course if you keep a small pair of vise grips in the trunk you can clamp off this hose from the engine without issue and get home and fix later, but left off and you wont get far

 

So I had the car in yesterday for the RH headlamp repair (sagging ****).

I also asked them to look for the leak. I am losing coolant.

They found nothing. Again. They said they washed everything off while they had the belly pan and bumper facia off for the headlamp repair.

I get home and after an hour's drive it stinks of hot coolant.

I guess I'm going to have to fix this or at least find it for them.

Apparently this is going to be one of those frustrating chase it almost forever issues.