i had a question to find out some tell signs that my coolant seals are going bad or already need replacing. went to start up my car a couple days ago and noticed a funny sound like it was struggling to start. then right away i noticed a smell of coolant in the air so i then went to the back of the car to look at the exhaust and noticed a bit of smoke with a faint smell of coolant. as soon as the car warmed up the smell and smoke both went away. so my question is how do i know if my coolant seals need replacing or is it something else...? thanks in advance for any help...

 

1) Mysterious disappearing coolant
2) Bubbles while the engine is running
3) Overheating / boiling coolant