JimTrail

Hello Honda-Tech forum;

Question: Can a mechanic test the expansion value in my Honda Accord to see if is not working properly?

I have been having the same problem now for a couple of years.

Here is a thread I started here two years ago:
https://honda-tech.com/honda-accord-...-cold-3152427/

Firestone Tires here locall had an advertisement "A/C checkup $19.95."

I pulled in and asked the person at the counter could they check to see if my a/c expansion valve was working properly. He asked could I leave the car.

The Firestone technician did not give me a definitive yes or no answer or the answer he gave me did not seem definite one way or the other.

----- Two years, one year ago below ----------

First Mechanic: I took my car to a mechanic before the one in the above thread. That was in the year 2013.

He told me that my compressor was leaking freon and needed to be replaced.

Second Mechanic: I took it to the mechanic in the thread above for a second opinion. The second mechanic told me there was no leak. He said the a/c was 20 degrees cooler than the outside temperature (which was 70 degrees) and that may be as cold as it would get.

First Mechanic: I thought the first mechanic just made a mistake.

I then last year (2014) took it to the first mechanic for an oil change.

I asked his assistant to ask the mechanic if there was a way he could check the expansion value.

I came to pick up my car. Instead of $45 for an oil change he said the bill was $250.

I was a little bit shocked. The mechanic said that the nozzle where you put freon into the a/c was leaking so he replaced it. The guy turned out to be a real jerk. I never authorized any repairs. He was earlier lying about the compressor. He was lying about the nozzle.

----- Two years, one year ago above ----------

Third Mechanic: I found another mechanic. He told me that he would not replace just the expansion valve because that may not fix the problem. He said that he would want to replace the compressor or rebuild the entire system. That would cost about $800.

The a/c is still getting cool. It's about the same as it was in 2013. But now it's getting into the nineties and the a/c is just barely cool.

I would appreciate any information.

Thanks.

jollyhonda

By watching the pressure on a set of ac gauges you can sometimes conclude whether the expansion valve is working properly. With ac it is all about pressure. The expansion valve essentially controls the pressure on the low side of the system. I have seen then plug up and let no refrigerant thru. In theory one could become overactive and thus keep the low side pressure too high, causing warm air. You need those pressure numbers. If your condenser fan is not working properly that will cause high side pressure to be too high, and thus low side as well. If your condenser has a blockage or is not exchanging heat properly, same song different verse. But pressure is key. They refrigerant will be at a specific temp based on the pressure. Warm air is a sign of high low side pressure. That could be caused by a weak compressor not having enough suction, expansion valve stuck open, or a blockage upstream of the expansion valve. Since the performance of the system has remained consistent for two years I would rule out a leak. Another possibility is an over/under charge of the system when the initial work was done.
So Firestone made no recommendations for repairs?

JimTrail

jollyhonda;

Thanks for responding to my question.

Firestone didn't tell me for sure that they could check the expansion valve so I did not let them do a check.

So, basically there could be four causes:

1). Expansion value stuck open letting too much freon through into low side.
2). Condenser blocked causing freon to back up causing low side pressure to be too high.
3). Condenser fan not working causing temperature to be too high causing high pressure on low side.
4). Compressor weak not sucking hard enough from low pressure side causing pressure too high on low pressure side.

Which one of the above is the most frequent?

jollyhonda

Idk for sure. Expansion valve malfunction is really least likely in my opinion, unless it has trash in it. You really need to have someone put gauges on it and see what happens.

holmesnmanny

If your ac is working its highly unlikely the ev is bad. Normally they start sticking shut when they go bad.

JimTrail

jollyhonda, holmesnmanny;

Thanks for responding to my question.

Yesterday I pulled into the shade. I had a thermometer. It was 92 degrees outside. I held the bulb of the thermometer in front of one of the a/c vents.

The thermometer got down only to 88 degrees. It was only getting four degrees cooler.

It's going to cost $1050 (including sales tax) to have a new compressor, condenser, expansion value, installed according to my mechanic.

It's $200 to replace the expansion value (which may not fix the problem according to my mechanic) or $1050 to re-do the a/c system.

masospaghetti

Have you gotten the system hooked up to a manifold set? By monitoring system pressures you can get a very good idea what is wrong with it. You can get manifold sets from some parts stores for free with their loaner program.

Also, for what it's worth - it seems more common than not that the service ports leak a little bit. I've found that just tightening the cap down reduces this leakage to a tolerable amount. I think that mechanic did you a great disservice by replacing that hose assembly without asking.

A bad expansion valve could either fail open or closed. If it failed open, you would expect to see low pressure and temperature differential between the low and high side. You would be able to see this on the manifold set. If it failed closed, you would see a very high pressure differential between the high and low side. The system would probably keep shutting itself down to prevent an overpressure condition. Also - I've had to replace many failed compressors over the years, every single one of them had bad seals but ALL of them still delivered good system pressure.

Do you know if leak sealer products were ever used? This can cause the TXV to clog up.

If the system has too much or too little refrigerant, you will get insufficient cooling.

If the cooling fans aren't turning on, you will get almost no cooling at a stop.

If the system was overserviced with oil, that means there's less refrigerant to transfer heat, which means reduced performance.

djkurious

You need to grab a set of gauges and report back with pictures of the readings.
As many A/C systems I do in the summer, 99% of the time the gauges always tell the story.
Is there a Harbor freight in your area? Or better yet, Autozone will let you rent their guages
for a deposit and you get the money back upon return.

tim73

Yes

phootbag

If you can't aquire gauges and you cant evacuate and recharge the system, I recommend you find a real technician instead of these "mechanics" you've been visiting.

jollyhonda

Judging by the luck you have had picking mechanics...you may just need to wheel into the dealer. First of all, I dont understand why people want to keep changing your condenser. That is not a part you usually change on a whim. Of all the air conditioning work I have done over the years, I have replaced 1 condenser over the years, except for units physically damaged, and it was on my personal pickup. Replace the compressor, flush the condensor, replace drier and it would probably be kicking cold, unless you do end up with a txv failure.