Hi guys,
i am a new CL member and pretty much a noob student who is not aware of much mechanics of a car. Anyway, i just bought a used is350 2012. After driving it for nearly a month, i came across an issue, the AC did not used to do much cooling in the heat and i guess this is where i should have been cautious. i just took out my car the other day and the belt that runs the compressor pulley just broke. I had it checked at the mechanic and they said the belt broke because the compressor was jammed (jammed as in completely jammed, and does not move a single bit). Long story short, he told me i had to get a few other things along with the compressor replaced. Which has already cost me some good money. Now the only thing i am worried about is what might have caused the compressor to jam up and what i can do in the future to prevent it. i am afraid that after getting all the issues fixed,i might end up having the compressor jammed once again. Because i do not quite know what had caused it to jam up. My friend told me that it could be my aggressive driving and flooring the car too much because he had a similar experience with his Rav4's compressor jamming up due to giving the car full throttles. Since i do not quite know any other reason and i am an aggressive driver, that leaves me to believe what my friend is saying but again he does not have much experience with cars either. Did any one have a similar experience with their is350? Any help would be much appreciated.
thanks in advance.

 

I don't have any idea why the compressor locked up, but I can tell you that it is not because of the way you drive. Flooring the gas pedal will not cause the compressor to go bad.

My best guess is that you had a refrigerant leak because you said that the a/c did not cool well. All the refrigerant finally leaked out over the winter. There is oil mixed in with the refrigerant to lubricate the internal parts of the compressor and that probably leaked out, too. So the compressor locked up from lack of lubrication.

 

The vehicle is designed to protect itself. A probable situation is as mentioned above, a slow leak whereby the R134A and it's oil leaked off repeatedly and the previous owner recharged it without adding oil. A one time leak is not a show stopper. Repeated recharge and the system runs short on oil whereby the compressor self destructs as each time the charge leaks off, a small amount of oil goes away too. Mind you, you can't just throw an unknown amount of oil into the system at random. Its much more complex than that.

As stated, the car protects itself and when the AC charge is low, it disables the AC compressor. And although I may be mistaken here, I'm pretty sure it disables it during high rpm too. Its a variable rate pump not like a standard radial pump.

 

Yeah, the compressor (and sensors within the A/C systems) in our cars are actually pretty smart. It was probably a "simple" mechanical failure. Judging from your location, perhaps an abundance of sand/debris within the engine bay? Do you have all of the engine covers and more importantly the lower engine covers?

 

Yes, that was the cause. But, the mechanic at the workshop told me he replaced the compressor with a new one, cleared out all the debris from the system. When he ran the car again, the compressor jammed up again. He told me there was a computer issue. The computer does not turn off the compressor as a result the compressor keeps jamming up. I still did not understand much of what he was trying to say. Any further input on this?

 

The compressor in this car is a variable displacement design that doesn't cycle on and off during normal operation. It seems far more likely that the failure was caused by contamination in the rest of the system. You say he cleaned out the debris, but if he didn't do so properly, it would explain the rapid demise of the replacement compressor.

 

To explain further, if the computer detects an A/C compressor jam, it turns off the A/C and disconnects the magnetic clutch.

Which sounds like the opposite of what is now happening to your car?

Jeff

 

If the compressor is running all the time, I do not think that this would make the compressor jam. I live in a warm climate where the summer temperature is 100ºF (38ºC) or more and the compressor is running all the time without any problems. I would suggest you take the car to a different mechanic and find out what that mechanic says.

 

thank you guys for the replies. i appreciate the input. i will go see the mechanic tomorrow and perhaps take the car to a different garage. i will update you all with any further details. thank you once again.

 

In short when a compressor fails and depending on the type of failure it can require a complete system replacement. Any debris left in circulation can go through the new compressor and kill it.
Few replace the dryer and rubber hoses. Even fewer replace the condenser (in front of radiator) or the evaporator core. There is no sure way to get small debris or metal fragments out of this closed system and there is no filter in it.

Outside debris did not kill the compressor. Something inside did.

 

Sorry for replying so late but i had been completely caught up with university work.
Anyway, the issue was a refrigerant leak. I had the mechanic fix a new compressor with a new condenser and had the ac system cleaned.
Car runs beautiful now. But i am getting really bad fuel economy on the car(14-16 mpg 40/60 cty hwy). i guess i will make a new thread on it.
thankyou all for the input.

 

16mpg ain't too far off of some that have posted on here having an IS350. Personally, I net about 19-20 on any given week.

 

Tbh the car showed me the avg mpg to be 14 and when i did my own calculation it turned out to be precisely 13.8 mpg. Here's how i calculated it.
Refueled the tank to full. Right when the fuel light popped, headed to the gas station and filled it to full again and calculated the miles and the amount i filled the petrol.I wrote 14-16 mpg to makeup for the somewhat aggressive driving of mine, not too aggressive tho and also considering that 60% of my driving is highway. i think 14 or even 16 for instance is really bad