Having reviewed the forum for answers on an anti-freeze smell inside my Blazer, I have remedied several issues, but the smell continues. Having bought the vehicle used, I did a much needed coolant flush this summer. The stuff drained was really bad. New DexCool and distilled water was replaced and some Blue Devil coolant stop leak was added, because of a known frost plug leak. Shortly after that I began to smell anti-freeze inside the vehicle. I discovered the fuel pump was leaking from the weep hole, so I replaced the water pump and lower radiator hose in the process. Of course, new coolant was added. There appears to be no leaks from the water pump, gaskets, or hoses. After spraying engine cleaner and pressure washing the engine, especially underneath, I see no evidence of coolant leak anywhere, but still have the anti-freeze smell when I turn on the heater. I checked twice to see if it could be from the heater by pulling back the passenger side carpet and viewing up underneath the dash behind the glove box area. All is clean and dry.

Last week I also replaced the engine oil cooler hose that was leaking due to those crappy crimps. That is was why I really had to pressure wash everything underneath. Today, I had 4 new tires installed and had them inspect the vehicle for signs of coolant leak from below. They found nothing even though I drove the Blazer for several days after pressure washing.

So, could it be a intake gasket coolant leak without any obvious of leaking because of evaporation? I was hopeful that the Blue Devil stop leak would stop anything short of a fully blown gasket.

What would be the next step in finding the leak? Is there anything short of a full tear-down of the plenum, etc. to find the source of the anti-freeze smell?
I did replace the spider last winter and the gaskets looked good then, like they had perhaps been replaced. Anyone got any inspection tricks or ideas on how to proceed from here?

Thanks to all who have been so helpful in the past.

 

its possible it could still be your heater core. ive seen them leak very slowly where it just evaporates as it comes out and stinking up the inside of your truck. it just sucks cause its a big job to even check that.

one stupid thing you can check is your hoses going into your heatercore. ive seen them come loose and then a little antifreeze will actually roll down to your heatercore making it stink

 

Thanks "abig84".

I'm afraid your suspicions are probably as likely as anything right now. I will check the heater core hoses more closely and hope for the best. After just replacing the rear oil cooler line (ugg!), I don't know if I can muster the courage to do the heater core replacement. However, it sounds like it's just a matter of time before the core goes out on these Blazers anyway. I probably should just bite the bullet and replace it. I guess things just never end on these vehicles in order to keep them operational.

Thanks again.

 

loop the hoses on the heater core
take it out of the system
no heat but should tell you 100%

take a look at all the frost plugs again

 

To "loop" the heater hoses, do I just remove them and connect them together with a tube or line and clamp? Sounds like a good idea.

Also, yes- I am still suspicious of the frost plugs. I am hoping for a couple more warm days to show up here in Minnesota in order to work on this problem. It just seems one can never stay ahead of all the things that can go bad on a Blazer. Even the later year models.

I am very curious as to where the smell is coming from. I hope I can eventually figure this out.

Thanks for the suggestions.

 

Its coming from the heater core

 

yes connect the two heater hoses with a tube to bypass
99.9% its the heater core but the fact that you say you used sealer for the frost plug leak makes them the .01% IMO

 

99.9 % sure. Yikes & uggh. This job ani't gonna be fun.

Thanks for the scoop though. Think I need a beer.

 

Just a note about the Blue Devil, if you suspect at all that your lower intake gasket is possibly seeping coolant externally then you better believe its leaking internally too, using any type of "Head Gasket" magic cooling system fix chemical on these engines is flirting with disaster. Blue Devil is 60% water, 20% antifreeze and 20% SODIUM SILICATE, sodium silicate is what the dumped in the oil to destroy the engines on the "Cash For Clunkers" cars. When plain antifreeze gets in the oil it's bad enough, add concentrated amounts of sodium silicate to your oil and say good bye your bearings soon down the road.
The reason i say "Flirting With Disaster", many times ive replaced one cooling system component and then very shortly after another starts leaking, you plug one leak and then 5he next weakest spot springs another one, for instance on my own car, i had a 96 olds ciera with a 3.1 (Another bad designed intake gasket exactly like the Vortecs had) it had a water pump leaking for 6 months....it was cold outside, i had no garage, didnt care about the car and was just being lazy, i just topped it off every day or 2 and it was fine, finally in the spring i replaced the water pump, luckily i still needed heat in the morning and turned it on 2 days later to find i had none and looked down to see the temp gage running hot. Checked oil, choclate milk reading about 3 quarts over full. The point im trying to make is, if your intake gaskets are not new and you go plugging all the other leaks around them with "Liquid Engine Destroyer" , eventually they will fail, dumping that sodium silicate into your engines oil system, before you realize whats going on the engine is overheating, the hot oil has steamed off any water that was in your antifreeze/blue devil mixture and your oil is now overheating and highly contaminated with majorly corrosive and abrasive chemicals.
Wow sorry i typed a book, just cant stress enough, get that stuff out of yoir cooling system after you give it its time to work and change your oil a couple times in 500 miles.
SOOOooo many engines are lost to this "Majic Band-Aid" stuff. A couple hundred bucks to a GOOD mechanic to fix it right will be much much less than replacing the whole engine.

 

Yep just had the same problem as soon as you start smelling the sweet smell of antifreeze. Check any hoses that may be leaking on the engine causing steam. Then check your passenger side floor for moister because a heater core will often leak and the floor will be wet or damp. Sounds to me like the heater core if you live in the tropics and not worried about the cold you can bypass it with the inner and outer hose lines that go into the firewall to the heater core, ( coor is behind the dash on the passenger side in a box attached to the firewall.) Pull these off and get an adapter and a couple clamps.