I smell antifreeze inside

01, 5.3, 120k miles. It took about 20 minutes for the windshield to un-fog on inside and I am pretty sure I smell anti freeze also. Is my heater core gone bad? Is there any thing else to check. Thanks for the help.

I am not really familiar with your vehicle but it sure sounds (and smells) like a bad heater core to me.. :mad:

01, 5.3, 120k miles. It took about 20 minutes for the windshield to un-fog on inside and I am pretty sure I smell anti freeze also. Is my heater core gone bad? Is there any thing else to check. Thanks for the help.


remove the heater core hoses at the engine and using a 10 psi air pressure check that the heater core holds pressure. if not then you must remove the entire dash to get at the replacement of it. also the evaporator may need removal. ITS A BIG JOB.

WHAT ARE YOU USING FOR COOLANT ? HOW LONG BETWEEN COOLANT REPLACING ?

Here is my take on it. All of this could very well be the problem, but before you got through all of this. Check the floor boards for any coolant or coolant smells and wet spots. If there are any of these things, then this is a sure sign that your heater core is bad. If anything, you should take the vehicle to a dealership or automotive shop and have them run a pressure test on the vehicle. Or if you would like you can do this yourself just by spending 80 dollars for the pump at an autoparts store. It comes with different adapters. You attach it to your collant resevior tank and pump it up to the factory PSI and watch it. If you lose pressure then you have an obvious leak. And with pressure on the system it forces more at so it makes locating it easier

Just another note.....Check for leaks along your intake gaskets along the heads and check tour radiator.

Thanks for info. I use Dex Cool anti-freeze and flushed it out at 80K miles. It sounds like its going to be expensive and time consuming. I will post an answer when I find out what's wrong with the truck. Thanks again.

Thanks for info. I use Dex Cool anti-freeze and flushed it out at 80K miles. It sounds like its going to be expensive and time consuming. I will post an answer when I find out what's wrong with the truck. Thanks again.

A friend of mine worked for GM for 15 years and would kick anyone's butt who said they used Dex Cool. GM swears you have to use it but he tells me that is because GM owns the rights to Dex Cool and it's their money to make. Apparently it eats the hell out of your head gaskets (had mine go at 80k and used DexCool the whole time) - he said stick to Prestone don't listen to the Dex Cool requirements.

A friend of mine worked for GM for 15 years and would kick anyone's butt who said they used Dex Cool. GM swears you have to use it but he tells me that is because GM owns the rights to Dex Cool and it's their money to make. Apparently it eats the hell out of your head gaskets (had mine go at 80k and used DexCool the whole time) - he said stick to Prestone don't listen to the Dex Cool requirements.

my head gaskets are with no problems . this is with the other vehicles as well that I work on.

dexcool must be used at 60% to 40 % distilled water , replaced every 3-4yrs.

with your truck this means 2.75 gallons of dexcool.

with low dexcool the corrosion will eat the metal , the gaskets then fail,and fail, and fail.

non dexcool can be used IF you properly ACID flush the system and flush many times. alot of work with replacing every 2yrs instead of 3-4yrs. this is more work and cost ..

01, 5.3, 120k miles. It took about 20 minutes for the windshield to un-fog on inside and I am pretty sure I smell anti freeze also. Is my heater core gone bad? Is there any thing else to check. Thanks for the help.

yes i'm $100 percent sure it's heater core...