Smell of anitfreeze thru car interior vents, yet no leak detected, is it from the heater core?

Question

Radiator, and top and bottom hoses replaced along with the thermostat, but detecting smell of antifreeze now.

Answer 1

Just an example car....Fords w/ 3.8 engine had similar problem and it was the head gasket it was blown.

Answer 2

I swear I answer this 5 times a day. This is the situation: The automobile is full of coolant and the reservoir if full. After running the car for a few minutes it overheats then cools once shut down only to do it again and again. Boiling over the reservoir if opened. The coolant is replaced and it happens again. I'm frustrated! Don't worry this is a very common problem with an easy fix. This is the problem: The engine coolant was at sometime in the past low enough to let an air pocket in behind the thermostat. Usually engine work was done that allowed the coolant level to drop and this problem resulted. All thermostats have a tiny hole or notch cut in them to avoid this but because of degrading gaskets, loose silicone blue goo, and contaminates these vents become blocked. This traps the air pocket behind the thermostat. Your car now needs “burped”. I'm not trying to be funny, that's the technical term for it. This is what is happening: The air bubble behind the thermostat keeps hot coolant from coming in contact with the thermostat. Without coolant touching the thermostat it will not open. If it did the system would burp itself and the problem would end. So, the thermostat stays closed and the coolant boils over entering the radiator backwards, cools and the cycle starts again. If you were to open the radiator cap it would shoot coolant out like a shotgun then sit and percolate like a coffee pot. How to fix it: You can burp your car by finding the highest point in the coolant system behind the thermostat. On American V8 cars this is almost always the heater hose. As for imports you'll have to use your best judgment but it will probably be the heater hose or carburetor heater. Some fuel injected cars use manifold heat too. Anyway, find the highest point and vent it by removing one end, the highest one. Now, if done correctly the coolant system will now accept more coolant, usually at least another gallon. That is how you'll know if it was the problem, by all the extra coolant you can now feed the system. Keep adding until if flows out your vent. Replace the vent and top off the coolant again. Your problem should be gone.

Answer 3

It is most likely the heater core. If could also be a pinhole in a heater hose spraying antifreeze near the air intake, but the odds are with the heater core!

Answer 4

Yes,it's probably your heater core. I had this happen in a '84 Mustang..in the middle of a snow storm so I had to drive home with my windows open since the defroster no longer worked. The smell was awful!

Answer 5

sounds like a small leak in the heater core or a small leak in a hose

Answer 6

Heater core most likely leak.

Answer 7

that sounds like the problem. coolant has a sweet smell to it. if heater core leaking should have wet carpet in that area

Answer 8

unfortunately, i have to conclude that it's 99.7% gonna be the heater core .... as it gets worse, you should notice the passenger side front floorboard getting wet with coolant/antifreeze .... your windshield should also start fogging up real bad when the car is running

Answer 9

Yup its the heater core

Answer 10

have seen alot of vehicles with same prob, inspect the two lines in the engine compartment that go through the fire wall,where they go through sometimes the line will crack. Mind you, it might also be behind the dashboard.