Mechanics, I need your help!!

[captpete]

Here is the deal. I have an '08 Chevy Colorado with the 5 cylinder motor & automatic transmission. About 2 years ago at roughly 32,000 miles I had to put a new radiator in the truck. Last fall I noticed a slight anti-freeze smell from the front of truck. Now I'm getting a strong smell. I had the person that put the new radiator in check it over and he can not find a leak anywhere. I put on a new radiator cap and still get the smell. As soon as I open the hood the smell goes away. I'm not loosing any anti-freeze....the over flow tank is still in the same spot where I marked it last week and the radiator itself is full. I have only had the smell in the cab once(2 weeks ago) when I turned the heat up and have not been able to get it to do it again. I have power washed the motor and engine compartment but still get the smell. I spent over an hour today checking hose clamps / connections and can't find anything that indicates it is leaking. I even blew trough the hose that goes to the overflow tank to make sure it was not plugged.

Any thoughts or ideas of what is going on what else to check.

[owlhoot]

Did he pressure test it ?

[fallhnt]

Could be loosing a small amount during expansion and contraction when cooling down. You can put some stop leak in it and take care of it that way.

[MK M GOBL]

Did you smell your exhaust or is this just and engine bay thing? If there is a sweet smell in the exhaust you are leaking in to the motor...

MK M GOBL

[bbcoach]

Have you checked the heater core and the hoses that attach to it?

[BOFF]

Your heater core inside the vehicle may have a small leak.

God Bless,
David B.

[outdoors]

Your heater core inside the vehicle may have a small leak.

God Bless,
David B.

X 2
CHECK THE FLOOR AND SEE IF U FEEL ANY WATER........

[Devastator]

Had a colorado and it was junk,went Toyota and am not turning back!!

[captpete]

I'm not sure, but I don't think he pressure checked it.

I did not smell the exhaust. The smell I'm getting is coming from the engine compartment after it has been driven.

I have not physically checked the heater core...it's buried in the dash. We have checked the hoses and connections in the engine compartment.

I have checked the floor/carpet in the cab and they are dry. I have only smelled this once in the cab and that was when I turned the heat up. I have not been able to get it to do that again.  It has been 2-3 weeks since that happened. I'm guessing it pulled the smell in from the engine compartment.

Hate to get rid of a truck with only 51,000 miles on it because it started smelling like anti-freeze.

The weird part is the anti-freeze level has not dropped. The level in the overflow/expansion tank is right where it was when I marked it last week and the radiator is full....I put a new cap on this morning.

[paboxcall]

Could be a gasket and small leak into one of your cylinders.  That would cause the smell in the engine compartment, but not enough to notice a decrease in the coolant level.  Does it idle a bit rough when you start it, and sit at a red light?

[coyote1]

Check the weep hole on the water pump. It can leak very small amounts of coolant that would take a long time to notice any significant change in coolant level. That's the only thing i can think of other than the suggestions in previous posts.

[the Ward]

That's a head scratcher for sure. Strong smell of antifreeze usually happens when its hitting something hot and burning like the exhaust or when the motor is hot and it's coming out of a leak as a steam vapor. What's unusual is you are not losing a visible amount of coolant in the tank or radiator. It might be a tiny pinhole leak in a hose, perhaps in the heater hose after the heater control valve. Or like has been suggested, the weep hole in the water pump. A pressure check should be able to show you where it's leaking.  Stuff like this can drive you crazy sometimes trying to figure it out!

[captpete]

Thanks for the ideas and responses. I guess my next step is to get it pressure tested. If that doesn't show anything I wait until it does show up.

[Tail Feathers]

Your heater core inside the vehicle may have a small leak.

God Bless,
David B.

My first thought too.