Slight coolant smell when starting each morning

[Clint Beastwood]

Hi all - 2017 with ~2300 miles on it. I noticed over the last few days I smell coolant for maybe a minute after I start in the morning. I *think* the ST uses a closed coolant system, but I figured I'd ask before I went to the dealership. I'm not finding any drips, car runs fine. Temperature when experiencing the smell is approximately 45f-47f. Is this a normal quirk of the ST?

 

[blongo804]

I've smelled this before, both after starting in the morning, and after parking and walking behind the car. Odd, but hasn't bothered me since there's no leaks I can see and the car is under warranty. Just about 2500 miles on mine.

 

[apex1]

3500 miles on my 2017 and I have a slight coolant smell too. If the level ever starts to drop I will deal with it then.

 

[kivnul]

2016 w/ ~20k miles, I have never smelt coolant.

 

[zanethan]

2015 here w/12,000 miles. No coolant smell here. I'd take it in.

 

[MichiganST]

Isn't a coolant leak what our recall is for? I think the dealership has a service bulletin out to install a coolant level monitor or something along those lines as a permanent fix isn't available. Either way, I wouldn't take this lightly. Better to take it in and have the dealer say there's nothing wrong than to have your engine blow up... I've never smelled coolant in my '14 and I just broke 51k miles.

 

[Clint Beastwood]

Found the recall - doesn’t look like it affects me. https://media.ford.com/content/ford...-recalls-and-one-safety-compliance-recal.html

I’ll monitor it - I marked the level with a sharpie. If the level changes I’ll take it in.

 

[Sprinkle_Star]

I remember having to bleed a little bit of air from the radiator when I first bought mine new in May, but that's the only cooling system issue I've had.

Mine's at 9,030 miles, and it's a 2017.

 

[Plainrt]

I had this when mine was newer but haven't noticed lately. Mine is a 15 and 64k miles now. Never worried too
Much about it.

 

[Sprinkle_Star]

I have an idea; maybe your radiator bleed cap is not fully screwed in. You can find it in the back of the radiator in the middle on top; it looks very much like a tire valve stem cap in fact.

I've found that it's terribly simple for coolant to seep out from there if the cap is loose enough.

 

[me32]

Hows the coolant level on your car? Id keep it close to max and just check it. I dought its anything. The 2017s dont seem to have an issue with coolant

 

[redmoe]

Bringing this one back from a few months back. Just noticed a coolant smell outside the car when my GF started it up to head for the gym. I’ve had a couple other new cars do this in the past just wondering if any other 16+ owners have noticed/addresses it? There is no smell in the cabin so you would have to be outside the car to get a good wiff of it.

 

[green_henry]

Bringing this one back from a few months back. Just noticed a coolant smell outside the car when my GF started it up to head for the gym. I’ve had a couple other new cars do this in the past just wondering if any other 16+ owners have noticed/addresses it? There is no smell in the cabin so you would have to be outside the car to get a good wiff of it.

Did you install silicone coolant hoses when you installed the Mountune radiator? If so, it's most likely the hoses but is nothing to worry about. I haven't noticed it yet with the Mountune/Samco hoses, but I had the same issue when I replaced the hoses on my Acura TSX -- those were HPS rather than Samco.

 

[redmoe]

Did you install silicone coolant hoses when you installed the Mountune radiator? If so, it's most likely the hoses but is nothing to worry about. I haven't noticed it yet with the Mountune/Samco hoses, but I had the same issue when I replaced the hoses on my Acura TSX -- those were HPS rather than Samco.

I did install the whoosh hoses. Do you know why this happens. Also thanks for the reply!

 

[redmoe]

Just did some web searching and apparently the silicone hoses permeate the coolant more than rubber yielding the coolant smell. Never would have thought that was the cause. Thanks again

 

[TyphoonFiST]

Just did some web searching and apparently the silicone hoses permeate the coolant more than rubber yielding the coolant smell. Never would have thought that was the cause. Thanks again

That's one I've never heard.....Craziness! Learn something new everyday! Weird!

 

[green_henry]

I did install the whoosh hoses. Do you know why this happens. Also thanks for the reply!

Silicone hose is more permeable than rubber hose. If you search the web for "coolant smell from silicone hoses" you'll find lots of content. So far, I'm impressed that I haven't noticed the smell from the Samco hoses -- with the HPS hoses on the TSX, it was noticeable right away but hasn't been a problem.

 

[Quisp]

Anyone with a Mishimoto catchcan knows firsthand about silicone permeability.