I was recently in a front end collision with my 1996 Civic LX. Most of the damage was to the radiator, condenser, and condenser fan. The A/C quit working after the wreck. The condenser fan got pushed into the engine and it is not able to run without rubbing so I disconnected it because it kept causing the condenser fan/compressor clutch fuse to blow. Replacing the fan isn't possible unless I get the front end of the car straightened out which probably isn't going to happen since it has 200k miles on it and it has been running fine after I replaced the radiator (except for the A/C).

I had the system evacuated and replaced the condenser and the drier. It then seemed like the clutch wasn't engaging so I had it evacuated again and replaced the compressor and clutch. The A/C runs for about 10-20 seconds and the compressor shuts off due to excessive pressure on the high side (~400 psi). The low side pressure is normal (~20 psi). The guy at Autozone seems to think that the expansion valve needs replaced. Before I dive into another costly "fix", I thought I'd get some additional opinions.

1) Is it likely the expansion valve is the culprit or could there be another blockage in the system? Any way to locate a blockage?

2) When I replaced the compressor, I drained the oil out of the new compressor and added 5 oz of PAG46 oil. I don't think this would cause the high side pressure to be too high, but is it possible I added too much oil? About 2-3 oz drained out of the old compressor.

3) I've read postings about having the system flushed. What exactly does this do and would it help? Will this clear any blockages? Should this be done before or after I replace the expansion valve?

4) Do evaporators go bad and should I replace the evaporator while I am replacing the expansion valve?

5) I've read mixed comments about the condenser fan. I've read some postings that say the condenser fan doesn't provide much cooling at speeds above 40 mph and it not working could possible cause overheating at low speeds with the A/C on. I've also read that it is required to have the condenser fan running to prevent high side pressure from going too high. Is the condenser fan required to have an effective A/C system?


Thanks in advance,
Ron

 

You need the condenser fan. For example, read this thread:

https://www.hondacivicforum.com/foru...ad.php?t=74986

 

So will the condenser fan not running cause the high side pressure to be 400 psi shut the compressor in 10-20 seconds? I haven't tested the A/C on the highway yet for fear of doing damage to the system. Is it possible the expansion valve isn't working properly or there is a clog in the system? Is there a way to test the expansion valve?

Thanks,
Ron

 

Absolutely you need a condenser fan with the car sitting still, or exactly what you describe will happen. You can test drive like it is to prove it to yourself, but be sure to release the A/C button whenever you slow down. Don't count on the switch to work all the time, it is intended for abnormal conditions only. If the switch doesn't act to kill the compressor in time, the pressure will keep rising until the relief valve (or a line, or the compressor case) blows out.

 

You do indeed need the fan running. But at the same time, a minor kink in your refrigerant lines can cause abnormal pressure readings. I dont think it would be an expansion valve, TXV's dont go bad too often and I dont see how a wreck would destroy it.