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Antifreeze smell

I had a wet carpet, antifreeze smell, and fog on the windshield. My mechanic replaced my heater core. Off on and on I still smelled antifreeze but no fog anymore. I waited 2 weeks for the smell to go away. Maybe residue. Then I smelled it strongly with my heat and blower on one night and took it in the next day. The antifreeze in the reservoir was almost empty. The mechanic filled it. He has had it a couple of days and says he sees no leak or the coolant down. He doesn’t smell anything. Anybody know what’s going on? The car is a 1995 volvo 940. I’d appreciate any help in how to deal with this.

Since the heater core has been replaced and you are loosing antifreeze the next probable item for failure would be the hoses, or clamps going to the heater core. It is possible the heater core replacement was a defective unit, and I would start with the mechanic who did the heater core and ask for a check of the system describing it as you have posted here. Most mechanics I know want a good word of mouth recommendation, and letting him/her know you had this work done and still have a problem and if they can fix it will encourage you to send more people their way!

I think there are two problems:

  1. The residual antifreeze odor from the original leak, and

  2. the new, stronger smell and possible loss of coolant.

Theory for 1): You say “I had a wet carpet,” which means the antifreeze dripped onto the carpet. Antifreeze takes a LONG time to evaporate, which means you’ll smell it for a while. In addition, the padding under the carpet may have soaked up some of the leaking antifreeze. This padding is a sponge-like material, which will hold any liquid (water, antifreeze, beer) like, for lack of a better term, a sponge.

The only way to dry the padding (if it’s wet) is to get it out from under the carpet (easier said than done) and allow it to dry outside. If you find your under-carpet padding soaked with antifreeze I suggest hosing it off really well, with clean water, before letting it dry.

The fact that you have no more fogging is a good sign. Maybe the antifreeze is just in the carpet, and not the padding. If this were my car I’d want to check the padding, just to be sure.

Questions for 2): When you smelled this new, stronger smell, was it the first time you used the heat/blower since the heater core replacement? Do you have the car now, or is it still in the shop?

If you haven’t already had a pressure test on the system, have that done. i was the only one who smelled antifreeze in my pickup. When my mechanic did the pressure test, a leak in one of the hoses became apparent. Good Luck.

Agree with the pressure test recommendation. If there’s still a leak somewhere, that will reveal it. Otherwise, you’re smelling residual antifreeze stink from what the carpet absorbed.

I should add that the coolant reservoir tank might appear low if there was some air in the system, especially since it was opened for the heater core removal/installation.

Thanks for the reply. The mechanic said he?d checked for leaks and I assume that included clamps and hoses but I?ll check on that. Is there a way to check for a defective core other than taking off the dashboard, etc., in effect doing it all over again? As yet the mechanic hasn’t acknowledged a problem.

Thanks for the reply. The car is still in the shop. With respect to the carpet, I had a carpet mat on the floor. I took it out after it got wet. Subsequently, after the heater core replacement, I vacuumed the floor a few times. It didn?t seem wet at that time. When I get the car back, I?ll check again. I kind of doubt that the smell is coming from there though. The smell seems to happen when I have both the heat and the fan on, and whether the fan?s dial is pointed up, down, or to the side. The fan seems to be the biggest reason. It?s been two weeks since the replacement and I?ve had the heat and fan on a number of times.

Thanks, I’ll definitely ask about a pressure test.

Thanks, I’m going to ask my about the pressure test. I believe my mechanic filled the reservoir after the core replacement. I saw it was low two weeks later.

While I agree with all of the above and you should follow the advice, you may find a dead end, with no new problems. It is possible that there was an air block when the system was refilled after replacing the heater core. That could have explained the apparent loss of coolant.