A/C broken after engine replacement

Had my engine replaced. Immediately noticed that A/C didn’t work. (Had been ice cold and fast to cool.) Told mechanic. He said I could bring it back another day and they could charge it for $80. I bought 134a and tried to charge myself but it would work. So I think the condenser is the problem. I KNOW it was something the mechanic did. Any suggestions? (Student with no extra $$)

In order to pull the motor he more than likely would have had to disconnect the AC compressor and its refridgerant lines. Odds are that he simply omitted recharging of the system. The cost to replace the motor shoudl have included that, but I can understand someone overlooking it. We’re all human.

You think it’s the condensor? The condensor doesn’t actually do anything. It has no moving parts. The fluid after having removed the cabin heat via the evaporator (a heat exchanger) is forced under pressure by th ecompressor through the condensor (another heat exchanger) where the heat from the cabin and the heat from the compression of the refridgerant is dissipated. It then moves back through the evaporator where it decompresses, chills, and removes heat from the cabin again.

You can drive the car without AC until you get some cash without doing any damage to it.

This is not something you are likely to be able to remedy yourself.

Does the compressor run? One possibility is just that something (like the compressor) was unplugged or disturbed and not hooked back up.

If it is just low on refrigerant, you probably can’t get it charged back up yourself. If something happened that resulted in the loss of refrigerant while the engine was being replaced, the system is probably contaminated with air and moisture. Someone with the right equipment and knowledge will have to completely drain the system, put it under vacuum (at this point they can find out whether it is leaking or not) and then fill it with the known correct amount of refrigerant. The only “good” news I can give you is that if you added some refrigerant then what you just added will be recovered and reinstalled during that process.

You don’t mention the year, but I’d imagine it is somewhat older and high mileage. In this case, it wouldn’t take much to disturb the system’s parts in such a way that it would lose refrigerant.

Fixing AC takes a lot of expertise and expensive equipment - you need to just bite the bullet and bring it back in. Explain that the AC was perfect before the engine replacement.

The normal procedure when removing an engine is to unbolt the compressor from the engine and set it aside without disconnecting the refrigerant hoses. This eliminates the need to evacuate and recharge the AC system after the engine is replaced.

However, when removing an engine a lot of electrical connectors have to be unplugged. So the AC might not be working because something didn’t get plugged back in after the engine was replaced.


Flesh this story out a little…Replaced with a used or new engine?? Why? Model year and mileage of car??

this is a 2001 toyota corolla, engine “threw a rod” and no longer worked. Told it needed another engine. Replaced with a used, newer and lower miles engine. The car has about 100,000 miles on it, the replacement engine had under 50,000 miles on it. It was a cold day when we picked up the car so we didn’t try the A/C b/c we didn’t even consider something would be wrong after a big job like that.

When trying to add the freon the usual noise of the “condenser”? didn’t turn on and suck out the freon from the can. The can dial showed no pressure but there was a little I could hear when I hooked up the blue hose.

So since the thingy didn’t turn on, that is why I’m assuming that is the problem. I feel so stupid not knowing the right names but I am learning. I did manage to change the rear shoes. That is something.

So now what do you think? I think they will just claim no fault and still charge us $80 to recharge. It just angers me since it was great before they did the work and zero good after.

Ok, so I think it is the compressor. It doesn’t turn on when the car is idling with the air on high and blower on high. It didn’t suck out any freon. the gauge showed less than the minimum pressure on the gauge but it did make a little hiss when connecting it. The thing is we paid $2000 for a used engine, and got a broken A/C system. We think they should make it right and not for the $80 they wanted after the fact.
They charge more than doctors per hour. Where are the honest ones? I know they are out there but I feel like they prey on our ignorance.

If $80 more makes everything work right, consider yourself LUCKY…May times, these engine swaps turn into endless nightmares from which there is no waking up…Believe me, your air conditioner was the LEAST of your mechanics concerns…

The “compressor” is the part that is not kicking in. The “condenser” is the radiator in front of your other radiator…