Question:

I have a 2003 dodge neon se, my daughter was driving my car and noticed smoke coming from the vents when the a/c is on. A friend of hers was nice enough to put anti freeze since it was low ( I thought when you get an oil change that also includes topping off the radiator flud?) What exactly does that mean? There is no smell but now I have to put it in the shop.

Answer:

Smoke can mean many things. Was there a sweet coolant smell coming out of the vents? Its possible the low coolant and the smoke are related to a blown heater core. The heater core is basically a radiator, where the hot engine coolant runs through to heat the interior of the car. There is a fan which blows over the heater core and heats the interior air. While she had the A/C on, the heater core could still be bad and leaking coolant, causing the smoke.

If there was no sweet smell, it was more than likely the A/C working so well that it was causing an icy fog which does happen from time to time, depending on the humidity levels outside.

I would keep track of the coolant level, see if you lose anymore and if so, get the heater core checked out.

Question:

I had a water pump and hoses replaced on a 1995 Chevy G30 van, the morning
after I got it back I noticed a small 2″ spot of a yellowish-green oily
fluid on the driveway. Thought it might be some residual antifreeze driping
off the engine. By the next day I noticed my A/C seemed to not be getting as
cold as usual and 2 days later it started cycling of and on, by the next day
it would not cycle the the A/C on at all and was not cooling at all. I took
back to the service department and the said they found refrigerant leaking
from the A/C Compressor High Pressure Cutout Switch and replaced it. When I
was talking to the tech doing the repairs and explained that I just had the
water pump and hoses replaced and questioned if the switch could have been
damaged then he seemed to think that it could have happened. When I went to
get the car and told the service manager my story he stated that there was
no possible way that they could have caused the leak in the switch. He said
it was just a coincidence that the leak started when it did. I was just
wondering what your opinion was. If you have ever heard of a A/C Compressor
High Pressure Cutout Switch just start leaking on its own before. Thank you
for your time any comments.
Answer:

Rick,

I get a lot of questions from people wishing to retrofit their R-12 System
to work with the new R-134a refridgerant. I am no expect A/C guy but I
know some guys who are. The guys a www.autoACsystems.com
have written a great article on what is involved in a retrofit job.

Retrofitting auto A/C Systems
Up until the early 1990’s, all auto A/C Systems used a common refrigerant
known as
R-12 (Freon). It was relatively inexpensive and very efficient at transferring
heat. However, it was eventually discovered that R-12 (along with all other
CFC’s and some other substances) had a very sever negative impact on the
earth’s ozone layer. Therefore, R-12 had to be replaced as the preferred
refrigerant.

With most industrialized nations signing the Montreal Protocol (1987), the
elimination of R-12 was imminent. That created a lot of questions and concerns
within the industry. In addition to the concerns about finding a replacement
refrigerant, there was the issue of dealing with all the vehicle A/C systems
that were on the road already using R-12. This created even more questions and
concerns. In order to address all of those existing R-12 systems, it was decided
that they should be retrofitted to use another refrigerant. Once again, more
questions and concerns.

I have been around cars all my life, and the least understood system to me, is the air conditioning system. The folks at AutoACsystems.com have an excellent line of e-books detailing the operation of automotive A/C systems.

I have also updated my AutoShop101 pages and added a little more information about air conditioning and heating systems. HVAC Systems

Kevin Schappell