I have a 2004 TL with 92K miles on it. 2 years ago my AC stopped blowing cold air. When I had it serviced, the dealership replaced the compressor (which was out of warranty). For 6 months everything functioned perfectly, then one day when I turned the car on a "burning rubber" smell came out of the AC vents. When I turned the AC to off, and left the fan on it went away. When I turned the AC back on there was no smell. The strange thing is most of the time when I turned the car on with the AC on there was no problem. But about 1 in 20 times the burning smell would be evident on crank-up, and go away when I turned the AC off. This went on for a few weeks until I noticed the "burning rubber" smell while driving one day and then saw smoke coming from under the hood. I had it towed to the dealership who said the compressor was "burnt up" and replaced it. This same experience has happened 2 more times and follows the same pattern: Burning smell sometimes on startup, burning smell while driving, AC stops blowing cold air, smoke from under the hood, compressor replaced. I am now on my 4th compressor and the dealership has not been able to figure out the problem. Any ideas or similar experiences? Car works like new other than this recurrent problem.

 

Begin by Googling "AC BLACK DEATH". This pattern is unfortunately common to every later model car and manufacturer. I am not going to give a long explanation, as you can find that for yourself, but here is the short version, and you can find some general info here ...
https://acurazine.com/forums/showthread.php?t=805682

Old timey AC compressors were large, heavy, and pump style (not going to give a mechanical explanation). When they ran low on freon, and were damaged, they were unlikely to damage the rest of the system.

Modern rotary AC compressor are small, light, and when they are damaged from low freon (leading to lack of oil), or lockup from wear, they spread material throughout the entire AC system: lines, condensor, evaporator, accumulator, etc. The junk which is spread is said to look like black 'gunk', hence BLACK DEATH. The only solution is to replace the entire AC system, everything, which may seem expensive and extreme, but with the replacement of 4 compressors, you have already spent that amount of money.

Early Ford 2000's A/C compressors had teflon seals, and were particularly prone to BLACK DEATH. But really, every A/C system has some degree of problems. You can Google to find which car manufacturers, and which A/C compressors, are more prone to this problem.

You need to find another dealer, or someone who understands modern A/C systems. There are some threads on this forum, for various model Acuras, who have had this problem, and commented on the 'solutions'.

Basically, the only way to avoid a repeat of this problem, after replacing the entire A/C system, is that at the very first sign of a problem, is to stop using the A/C and have the compressor replaced, or find the leak and replace the freon. Running the compressor for only a very short time, with low freon, will damage the compressor, and spread junk throughout the entire system.

Now supposedly, the system contains a low pressure switch which is supposed to prevent the compressor from running, when freon is low. But as you have observed, it does not always work.

Sorry, and good luck.
---eof

 

I've replaced compressors that have locked up with positive results, however, if each successive compressor locks up and debris is found in the system, more than the compressor needs to be replaced and the system flushed to ensure all contaminants are removed and even an inline filter can be installed on the high side to protect the compressor.

 

I've never heard of only replacing a compressor when there's a failure. Most systems have some form of an orifice plate or a restrictor of some sort. Many have some crude form of filtration. When a compressor goes there are some parts that are replaced automatically and others at the mechanic's disgression.

If the compressor froze up once and then worked fine for a while longer it very likely it's debris as was said. The burning smell is obviously the serpentine belt. I'm sure the system can be flushed really well, at least the evaporator and condensor and lines should be able to be saved. If this system has a drier, it should probably be replaced. If you decide to replace everything, I would probably go with something from the junkyard that looks to be in decent shape. Evaporator and condensors and lines do not wear out. The compressor is one of the only parts of the AC system that actually wear so I would have no problem using decent junk yard parts.

 

With 4 compressor failures i'm sure that there is a lot of debris in the system. I work at an international truck dealership and when we have a compressor failure we have a very long and tedious procedure on cleaning the system. Basically all the lines get flushed out with an a/c flush solution, compressor, condensor and txv or orifice tube and dryer get replaced and then the proper amount of refrigerant oil gets injected into the system and then recharged with the proper amount of refrigerant.

 

Did you have to pay for all four compressors yourself? or were some replaced under warranty by the dealer who installed them?

Keep in mind that I am not an A/C specialist - which is why I would encourage anyone with an A/C problem to educate yourself. Yes, replacing only the Compressor sounds *crazy* to me.

Anyway, based on what I have read, modern condensors are so efficient, because they are small and have just tiny passegeways, so that it is basically impossible to flush them out. Usually, the labor to do a thorough job will exceed the cost of a new one, including the installation labor. Some shops will insist on condensor replacement to give a warranty - some shops will clean the condensor.

Generally, again, based on what I have read, only the evaporator is not replaced when a modern compressor fails - everything else is replaced, basically because of the labor to clean the old parts. Of course, if you are doing the job yourself, a junk yard part, or performing the cleaning process yourself, may be an option.

Now, once you have trashed 4 compressors, even the evaporator may not be able to be cleaned. And that is surely a problem, because it is located under the dash.

Again, good luck and let us know how you proceed and what success you have.

 

^^^ x2 on the difficulty/impossibility of successfully flushing many/most modern condensors. I'm really surprised that after 4 burn-out replacements (much less one), they still didn't get a clue. Oh wait, it's a dealership, I'm not surprised

 

OP:
The dealership ONLY replaced the compressor each time?

What do the invoices say? Was anything else replaced/flushed?

 

When I had to replace my compressor last summer, the stealerships quoted $1200 - $1400! I got the Denso OEM replacement on Rockauto.com for around $225 BRAND NEW with the clutch pre-installed. My local shop charged me only 2½ hours labor to install it and charge the system. Total, $508 w/tax.

They don't call 'em stealerships fa nuttin ya know!
.
.

 

Depending on the problem, that's possible if the system didn't need flushing, or any other parts replaced.

As the condenser needs to be removed for drier replacement, one can purchase a new condenser, drier/accumulator and block assembly for @ $100, but the labor is the killer.

Looks like some of the guys on this thread read too much.