This is a question is touched upon in the FAQ section of the website “Why is my air conditioner blowing hot air”, but I’ve decided to take a question a week, and expand on it, give you more information.  The answer I gave in the FAQ is that it could be a number of things.  I’ll give you the answers from my perspective.  The good news is—it’s blowing, the bad news is, it’s not cold air coming out of the vents.  This would work better with a flow chart but that’s not possible so let’s proceed.  One of the questions I will ask if you call is:  Have you ever had refrigerant added to this system?  If the answer is yes then I would ask you how long ago.  Last year, you say.  “I have to add it every year”, is another familiar response.  YOU HAVE A LEAK.  Your air conditioning system is comparable to the human body.  The refrigerant is like the blood in your body.  You don’t add blood once a year unless you are bleeding.  Same thing with your A/C unit.  You don’t need refrigerant every year unless you are leaking. 

I’ve heard it all, starting with, “The last company came out and fixed my leak and charged me so-and-so dollars, but now it’s not cooling again.  I tried to call them but they’re out of business.”  Yep, sounds about right.  It’s very rare that a freon leak can be FIXED.  More times than not, the leak is in an area that can’t be repaired and the leaking piece of equipment must be replaced.  Another one I get is, “the last company put some stuff in my system to stop the leak, kinda like the stuff they add to leaking radiators.”  If someone tells you this, RUN!  Don’t let an A/C technician add anything to your system except refrigerant.  It doesn’t work and it can cause more severe damage to your system.  It can cause early failure of your compressor.  Acme has been around for almost 30 years.  We fix things and fix them right, the first time.  Our customer reviews will verify that.  Our customers depend on us to give them honest advice and make the repair they know is necessary.

Sometimes leaks start out small and refrigerant is only needed every couple of years.  Just keep in mind, adding refrigerant to any leaking system is throwing money away.  Some people think it’s okay to let them run low on refrigerant and just add when it gets really hot outside and the A/C system can’t keep up.  Just know that the cool refrigerant coming back to the compressor from the evaporator coil is what cools the compressor.  air handling unit autocad drawingIf the air conditioning system is running low on refrigerant then the compressor is not getting the same amount of cooling refrigerant and this will cause the compressor to run hot, which in turn can cause compressor failure.  ductless air conditioning unit reviewsIt’s a domino effect, as with most problems in the air conditioning system.  ac / dc power supplies encapsulated modules

A small problem dominos into a big one if not immediately addressed.  When you know your system is not cooling, immediately TURN IT OFF.  I’ve been to so many houses where the customer knows the air conditioning unit is not cooling and leaves it running, I arrive, say the condenser fan motor is out, and the unit is just running and running.  Keep in mind, the compressor and the condenser fan motor don’t talk, the compressor doesn’t know the condenser fan motor is not running, it only knows that it’s getting hotter and hotter by the second until finally, an internal switch notices this and shuts the compressor off.  But not before it got really hot.  Then the compressor is off long enough to cool and guess what, it comes back on, runs until it gets hot, shuts off, cools, comes on, gets hot….you see my point.  It’s hard on a compressor to do this.  The same thing can happen when a compressor runs low on refrigerant…gets hot, shuts off, cools off, starts back up.   The best thing is to have your system serviced each Spring before the really hot weather hits and make sure your system is running properly and full of refrigerant. 

If you know you’ve got a leak, stop throwing money away and have the leak located, repaired or replaced. What is the best way to locate the leak?  We use a “sniffer” type refrigerant locater.  Some companies use dye that is added to your system and then use a UV light.  As I stated earlier in this post, adding anything to your system other than the refrigerant is tricky and we just won’t do it.  Also, you can use soap bubbles to suspicious joints and try and find leaks that way.  It’s just the choice of the contractor, what they feel is the best way to locate the leak.  The most common place we find refrigerant leaks are in the evaporator coil.  One of the problems with evaporator coils is that they condensate.  As they condensate year after year, they will start to rust, as they rust, the rust will flake off causing pinhole refrigerant leaks, and lots of them.  Another problem with evaporator coils is the coil itself.  Like a radiator on a car, the coil has many pipes in a continuous pattern, back and forth. 

On each end of the back-and-forth pattern is a U-bend.  Each u-bend represents a weld.  The cheaper/lower quality of the coil, the cheaper the metal and workmanship in this coil and the quicker the coil will develop leaks within it. Since low refrigerant levels are so common and a problem at probably 90% of the air conditioning service calls in Plano, Tx or Allen, Tx that we address, or any of the cities we cover, I thought I’d give more information this Friday morning about refrigerant leaks and the problems we encounter.    Are the new-car extras, such as paint protection, underbody coating, and loan gap insurance worth it? Hi, i worked in the automoble field for 8 years, I was the CIO of a large 8 location dealer group.   Frankly, i would be leary of doing business with a company that is still pushing paint protectant or undercoating.  Undercoating is BIG no no as it will actually cause rust.  It traps water between the steel and the undercoating causing corrosion, it plugs up the door and rocker panel drains as well as drain holes in the uni-body frame rails. 

The dealers cost for the undercoating is about 250.00 including man hours, it is a huge profit booster and nothing more.  Although Paint Protectant will cause no damage, it does no good.  It is nothing more than an acrylic polymer protectant which can be purchased at an automotive store...cost for the dealer including man hours, 75-100 dollars.  It is nothing more than a profit booster.  Gap insurance is worth it, if you are involved in a collision and your car is a total loss, the insurance company generally pays you the trade value for the car.  Gap insurance will pay the difference between what the insurance pays you and how much you owe on the car.  for instance, if the insurance company pays you 2k dollars and you owe 3k, the gap insurance will pay the difference of 1k.  However, if you are finanacing 75 percent of the vehicle cost, then gap is not needed.   Here is my best advice, pay for the car and not a single additional item.  Pay no more than 10 percent over cost, ask to see the dealer invoice, add 10 percent and pay that price. 

Gap insurance can be purchased through the finance company after the purchase.  So, if the invoice states the car cost the dealer 20k, you offer 22k and not a dime more as that is a fair profit for the dealer.  Puschase no other add ons, none.  If they wont show you the invoice, there are plenty of honest dealers that will.  I would be very careful with this dealer.  Dealers also make money on financing.  for instance, they submit your loan for approval, the bank comes back and approves the loan at 6 percent interest.  The dealer will add 2 or 3 points charging 8-9 percent interest and the dealer gets the money for the points at the time of sale. Ask them how may points they are adding to the bank rate.  I summary, be careful.  dont fall in love as there are many dealers with the same car.  Offer 10 percent over the dealer invoice and purchase nothing else.  if the dealer gets defensive, fails to show you the invoice, or pulls other sneaky tactics...go to another dealer.  

to find the dealer cost for your car as well as many other informative car buying tips.I just bought a used SUV with 115k miles for my son . Should I pay to have the timing belt changed now? If it is the original timing belt, then yes - check your owners manual for the recommended changing frequency, but from a quick web search (not knowing your exact engine model) it looks like 60,000 recommended internal, and typically last 80-100,000 miles to failure if not changed. The most frequent comment (and a red note items on manufacturer's website) is that you probably have a "zero-clearance" engine, an idiotic design that means if the valves are not fully closed when the piston come to the top, it hits the valves and breaks or bends them or punches a hole in the top of the piston. Talk about planned obsolescence ! In short, if that is the case and your belt breaks or gets so loose it strips the "teth" off it or slips, your valve timing will be off, and could cause catastrophic engine damage that would require a complete engine overhaul or replacement !

Unfortunately, after looking at a video on how to change the belt, they build it so almost all the auxiliary equipment has to be taken off to change the belt - the alternator, water pump, radiator upper hose, power steering pump, air conditioner, etc - so rough cost is $800-1200 ! If you are getting it changed, it is also recommended to replace the water pump while it is off. Hopefully some Montero mechanic will hop on this question and expand on this, but NO engine belt of any type should be trusted to go 115K miles.Is a transmission flush really necessary?How much does it cost to change transmission fluid At a quick lube type place, with unknown brand of fluid - from about $30-60 depending if done as part of a general fluid change package or all by itself. If transmission fluid filters need replacing too (usually are changed with fluid change on an automatic transmission), more like $75-125 range. At dealer, using OEM parts and fluid, about twice to triple that. Normal auto repair shop about halfway in between those two.

One reason for higher price is they will not (if reputable) extract the old fluid through the dipstick tube and put in new - they will remove the pan or maintenance panel (which commonly has to be done fgor filter replacements) and clean the pan at a minimum regardless. This assumes you do not need band or continuously variable shift friction surface replacement or adjustment, which can crank it up from $50-100 for band adjustment to several hundreds more for replacements. Do NOT let some shop convince you to pay for a transmission flush - not only is it unnecessary, but usually uses contaminated fluid from other cars or harmful chemicals (sometimes even tap water or diesel fluid) and can seriously damage your transmission. If your transmission filters were not doing their job or you smoked your transmission fluid, the proper cure (assuming not bad enough to require transmission overhaul) is to change to new fluid and filters, then replace them again in a short time - typcially 50-250 miles recommended by manufacturers, to let the new fluid pick up the dirt and sludge and transport to the filters for cleaning.

IF manual transmission - from about $40-75 for one with drain pan and no filters, to as much as $200 range for one with filters that requires removing side panel to change filter and clean it out. Again, higher end at dealers. My recommendation - ALWAYS require OEM fluids be used for all but engine oil - mixing brands and additives in equipment is just not a good idea, as they can react with each other and cause serious degradation of the lubricating properties, and even cause gel or sludge in the fluid. A transmission, transfer case, differential, etc should be able to run at least several hundred thousand miles without maintenance if you change the fluid as recommended and use only the same OEM fluids in it. The small amount you will save using cheap fluids is not worth the mega bucks to repair or replace a damaged unit. If you go to an auto shop, find out your required refill quantities and buy the fluids at the dealer and tell them to refill with those - just be sure to get enough to allow for a bit of spillage.