I smell anifreeze...

I have an 04 4S cab with 39k miles. I just noticed a faint smell of anti freeze when I open the hood. No drips on the ground and no heating/cooling issues. I just had it in for routine service and they said the coolant was fine. There is a bit of yellow grunge dried up around the fill cap. Anything to be concerned about.

By hood, you mean the front trunk? If so, you may have a sub-pinhole leak in one of the radiators, or maybe one of the clamps that connects the lines to the radiators needs attention. Could also be where the hoses connect to the heater core (behind the battery tray)...

Change the overflow cap even if you don't see any fluid. They are insidious little &%$# and they can slowly fail and you lose pressure which might be why you smell coolant. Its a cheap fix and if that isn't the problem at least you've eliminated the cheapest failure point. They are not much more then $30 bucks at the dealer. I changed mine and no more smell and I found the temp's now a bit lower over all.

Sorry, I meant engine hood. The cap could be the culprit. Having problems loading a picture - "parse error".

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Both my Boxster and Turbo had what proved to be leaking tank caps. The Boxster cap was leaking bad enough that in about one month the tank lost enough fluid to cause the low coolant warning light to go on. In both cases I never smelled anti-freeze from the caps. The only time I have smelled anti-freeze at the Boxster is from what proved to be a bad coolant tank. At the Turbo, I caught of a whiff of anti-freeze getting in of or out of the car on the driver's side. Upon visual inspection (with the car on a lift) the whiff was believed to be coming from an obviously leaking water pump. I had this water pump replaced and haven't smelled anti-freeze since. Get the new tank cap. Be sure to clean the tube where it threads on and must seat to form a pressure tight seal. Be sure the coolant fluid level is ok and note where the level is. Replace the cap then keep an eye on the fluid level. If it goes down again there's a leak.

I'm with Macster - even with a bad cap, I never smelled coolant. I smelled coolant when my water pump was going, and I saw and smelled coolant when it was time to replace the tank. Have you taken a look underneath? Drying coolant leaves telltale residue, so you may be able to eyeball the source by looking from below.

I'll take a look and report back. Thanks.

Here's a pic

You really have to get the car in the air and be able to get underneath the car and give every place from which coolant can leak a thorough inspection. The most common places are the underneath side of the coolant tank, which may or may not be that visible. A mirror on a stick is helpful. The other place is from the water pump. Look for signs of anti-freeze residue. In some cases there will be a white residue, a stain on the water pump casting. In this case this may be normal. I've been told the water pump seal can leak a bit, enough that the leak will create a white stain area but the size of this should be very small and there should be no signs of any wetness ever. But if you are smelling anti-freeze and if it is coming from a water pump leak you'll find more than a small white residue stain. With my Turbo's water pump there was a rather large blob of greenish anti-freeze residue under the pulley. 'course, to be thorough you have to check all hoses, where the hoses connect, and at the front of the car too at the radiators. If you want you can perhaps smoke out the leak. With the coolant tank topped up and a new cap on and properly installed drive the car around town until the engine is fully up to temperature. Leave the A/C off. You want to hear/feel the radiator fans coming on as this is a clear sign the coolant is plenty hot. Then at home in your driveway raise the RPMS to say 1500 and hold until the radiator fans come on. Then shut off the engine. The heat load in the engine will raise the coolant temperature and pressure. With everything hot and under pressure if there is a tank leak, or a hose leak, or any leak, the odds are very good it will make itself known. You have to be a bit careful. When I did this I was not that close to the car but the coolant tank finally let go and hot coolant came gushing out of the bottom of the tank. You want to look under the car for any leak sign but you want to be aware that at any time a leak can result in a gush of hot coolant. Also, use your nose. You already report smelling anti-freeze so with this "test" you will probably get a much stronger whiff of the odor.

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Change your cap. Look at the part number on the top, if it ends in 01 you have an early version that is susceptible to failure. I think the newest iteration ends in 04. http://www.suncoastparts.com/product...96WaterCooling What does your coolant look like? Open the cap & take a pic for us.

Looks like you got off easy this time. You may want to replace the water pump (assuming it's still original) before too much longer. A 2012 article in Excellence recommended replacing the water pump every 4 years / 50K miles.