Hey guys, new here... last winter I could smell antifreeze in the cab and also in the engine compartment. It was leaking a small amount. As soon as the engine warmed up, you could no longer smell the antifreeze. All Spring Summer, no leaks at all... Winter is once again fast approaching and I'm wondering if it's maybe just time to let this one go. I had to rebuild the tranny last year $3000... Now this... One shop did a block test and said I had a bad head gasket. Another shop did the same block test twice and said, no way, it's not the head gasket, both tests passed. I'm not sure where the leak is coming from, I did get a dye and put it in, but it hasn't leaked since I put it in. Any experience with this anyone? Is there a common issue with these things? I have 122K miles... I'm just tossed on keeping it and fixing it. If it can be another $2K bill... I'd let it go now and get something newer...

 

5.3L engine
you said it was leaking a small amount...where did you see the leak. head gasket problems are rare

 

When I first started to notice the smell I looked at the overflow and it was low. So I added fluid and began to keep an eye on it. I noticed the smell throughout the winter and tried to see if I could find it, but never could. I continued to add a bit of fluid into the overflow container as needed. Once we had no more cold days.. (ie. winter ended) it has not smelled like antifreeze at all and I have not had to top off the overflow container... I'm guessing once winter settles in again and we get the cold days and using the heat, it's going to start back up leaking and smelling of antifeeze. That is what I'm still trying to find is where the leak is happening. Yes 5.3L engine

 

Since you only smell the antifreeze in the winter time, could it be related to the heater core? If it's not leaking enough to where you can see it, I would put a bottle of Bar's in it and see if that takes care of the problem. Of course with the newer vehicles without a radiator cap, that's not as easy as it once was. Probably involves removing the upper radiator hose.

 

Ya, heater core is what I've been thinking. Can you just add the Bar's right into the overflow container? That being said, if I'm going to hang onto the truck I'd really like to find the root cause and fix it. I may just have to wait for it to get worse. The antifreeze smell though is kind of annoying... :-) I added that Dye the end of winter into the overflow container, maybe it never made it's way through the system.

 

Putting anything into the overflow reservoir will not get into the main coolant system very fast because there's very little circulation between the two. There is just the overflow expansion when the engine heats up and then as it cools down some fluid is drawn back into the radiator. Therefore you need to get it into the main coolant system for it to be effective.

 

Ahhh, dang, probably why I never seen the dye at the end of winter last year.... Well I'm 95% sure I worked out a deal on a new '17 Acadia Denali and trading this '07 Tahoe in... Appreciate the feedback guys! but I think it will end up being someone else's headache... :-)

 

That works for me.

 

Well dang... Seems for now this still might be my issue. I have the '17 Acadia Denali in my garage this AM. Dealership let me take it for an overnight test drive. Glad I did. After 40 minute ride my legs were going numb because
the seats cut into the back of your thigh. The seats do not come all the way up under the bend in your knee, so it was cutting in. Also after 40 minutes... I realized the thing is just too small. I'm so used to the size of my Tahoe at this
point I can not go to the Acadia. I hear the new Travers is bigger, but not sure I like the style of that. I think I'm going to be shopping for a used '15 or '16 Tahoe.

I don't know, we'll see, but for now I'll have to see if my Antifreeze leak resurfaces when the weather gets colder. I'll have to see if I can get the dye into the system, maybe get it into the top hose.

 

Sounds like you need a new heater core