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Discussion Starter #1
Hey all,

I am having a strange to me AC issue. My car is 07 FG2, 142k atm.

It will sometimes blow cold, but will always turn hot.

Example
Start my car, car warms up, turn fan speed to max, hit the ac button on the dash, AC is cool. As I start to drive, AC gets colder. After driving for 20ish minutes, AC blows hot.

I'm trying to understand this problem, not sure why its happening like this. In the past Its either been a on or off situation.

Any help or ideas appreciated.
 

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There can be 2 possible issues.

1. The AC fan motor is weak and not working at full speed - When you start the car, the engine takes 15-20 mins to reach optimum working temperature and until then radiator fan motor is able to take the load. After that since the AC fan motor is not working at full capacity, and the radiator fan which is already working at full capacity will not be able to take the heat load and so the heat management of the AC condenser will not be optimum which in turn increases the pressure in the AC system. This will automatically trigger the safety switch which will cut off the compressor completely and you'll start getting hot air after 15-20 mins of driving. So check and replace the AC fan motor. (I faced this problem in my 2007 Civic).

2. The hot and cold air mode selector switch maybe having issue and needs to be checked - At cold start since the engine temperature is low, you are getting cold air and once the engine reaches optimum working temperature (takes 15-20 mins from a cold start) you start getting hot air.

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I don’t concur with earlier post. We don’t know enough.

If it’s actually hot the compressor likely is not even engaged. These Civics have weak points and the relay for the mag clutch is a known weak link. In addition the mag clutch itself is a common issue causing the AC to nor work.

When it’s blowing warm pull over and leave vehicle on with ac on. Pop the hood and look for the compressor being engaged. Also verify the fans inside the radiator both are on.

If the compressor is not spinning test to see if voltage is getting to the mag clutch. The relay is a culprit if no voltage is available. If you do have voltage but the clutch isn’t spinning the compressor you likely need a new mag clutch. Read up on this issue as there are specific tests and a possible work around to temporarily fix it by removing some shims on the mag clutch.


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Discussion Starter #5
I don’t concur with earlier post. We don’t know enough.

If it’s actually hot the compressor likely is not even engaged. These Civics have weak points and the relay for the mag clutch is a known weak link. In addition the mag clutch itself is a common issue causing the AC to nor work.

When it’s blowing warm pull over and leave vehicle on with ac on. Pop the hood and look for the compressor being engaged. Also verify the fans inside the radiator both are on.

If the compressor is not spinning test to see if voltage is getting to the mag clutch. The relay is a culprit if no voltage is available. If you do have voltage but the clutch isn’t spinning the compressor you likely need a new mag clutch. Read up on this issue as there are specific tests and a possible work around to temporarily fix it by removing some shims on the mag clutch.


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Thanks for this will look into this one as well.
Changing out the radiator and ac fan, as I noticed the AC fan blade was turning on, but would slow down by about 30 - 50% as it worked.
 

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Discussion Starter #7
So....
Went to install the new AC and radiator fan assembly, and noticed my condensor seemed to be positioned awkwardly.
After some investigation, I noticed that the crossmember that holds the condensor had sustained some pretty serious damage.... This was missed by me when i bought the car. (angry)

I think that i will be able to bend the metal back into place-ish. but am ordering a new condensor as well. The one that is currently installed has sustained some damage on the bottom left side.

To be noted, the AC remained cold for longer than before after the fan replacement. Also, before, when it would start blowing hot, it would not blow cold air again. Now, if i wait about 5-10 mins, the air is cold again.
So progress, but no yet there.
 

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Not going to go into detail on your diagnosis but an intermittent AC is often a bad relay or mag clutch. Order two new relays and the expansion valve while your doing the job. I replace them when doing an AC job. The relays are a known weak link so replacing the mag clutch and fan relay is a good idea.

The expansion valve is a bit more difficult to get to but really is required if your replacing a condenser and compressor. Get the OEM valve as it includes the insulation around it and it’s not much more money then an aftermarket valve.

The radiator support can get easily damaged. I’ve had to replace and weld in an entire assembly after daughter had a run in. If condenser has been bent verify your radiator didn’t have any damage as well.

BTW I picked up a bunch of the good plastic retainers clips with a metal one way washer built into them. 10 times better holding then the plastic only clips. Search EBAY and you can find them easily. Good luck.


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Discussion Starter #9
Not going to go into detail on your diagnosis but an intermittent AC is often a bad relay or mag clutch. Order two new relays and the expansion valve while your doing the job. I replace them when doing an AC job. The relays are a known weak link so replacing the mag clutch and fan relay is a good idea.

The expansion valve is a bit more difficult to get to but really is required if your replacing a condenser and compressor. Get the OEM valve as it includes the insulation around it and it’s not much more money then an aftermarket valve.

The radiator support can get easily damaged. I’ve had to replace and weld in an entire assembly after daughter had a run in. If condenser has been bent verify your radiator didn’t have any damage as well.

BTW I picked up a bunch of the good plastic retainers clips with a metal one way washer built into them. 10 times better holding then the plastic only clips. Search EBAY and you can find them easily. Good luck.


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Appreciate the help!
I will be doing all of that now.

I am hoping to be able to bend that radiator support back into place, but we shall see.
Thanks for the input.
 

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I would recommend you figure out why the AC is getting warm after it gets cold, before discharging the system and replacing the condenser. It's not a good idea to add more variables to a problem and breaking into the system to replace the condenser is adding variables. Since the AC does get cold, it's obviously got enough refrigerant in it to work and it's probably not due to low refrigerant and a leak.

The question was asked above and needs to be answered...when the AC gets warm, have you checked to see if the compressor is running when that happens? This is a simple thing to check but is critical in figuring out what is going on. If the compressor is not running then it's an electrical issue. If the compressor is running but the AC is warm then I would suspect a possible internal issue, like sticking expansion valve.
 

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Had the same prob with my SI. Searched on this forum and found a test, something about taking a stick and pushing the mag clutch. If it engages then just need to take out shim. This was a few years ago so search for ac fix. Saved me $1000 and still have cold air. Car has 248000 miles and runs perfect, no rattles. It's only 240,000 miles to the moon so I could've driven to the moon.. and now 8,000 miles on the way back!
 

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Discussion Starter #12
I would recommend you figure out why the AC is getting warm after it gets cold, before discharging the system and replacing the condenser. It's not a good idea to add more variables to a problem and breaking into the system to replace the condenser is adding variables. Since the AC does get cold, it's obviously got enough refrigerant in it to work and it's probably not due to low refrigerant and a leak.

The question was asked above and needs to be answered...when the AC gets warm, have you checked to see if the compressor is running when that happens? This is a simple thing to check but is critical in figuring out what is going on. If the compressor is not running then it's an electrical issue. If the compressor is running but the AC is warm then I would suspect a possible internal issue, like sticking expansion valve.

I will look into that this weekend.
fingers crossed for NOT an electrical issue.

Thanks for the info.
 

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Discussion Starter #13
Had the same prob with my SI. Searched on this forum and found a test, something about taking a stick and pushing the mag clutch. If it engages then just need to take out shim. This was a few years ago so search for ac fix. Saved me $1000 and still have cold air. Car has 248000 miles and runs perfect, no rattles. It's only 240,000 miles to the moon so I could've driven to the moon.. and now 8,000 miles on the way back!

Nice, thanks for sharing.
I searched for a couple of days and couldnt find it. Admittedly, I may have missed it. But Will be checking into that come the weekend.
 

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I will look into that this weekend.
fingers crossed for NOT an electrical issue.

Thanks for the info.
Why? Way cheaper and easier than a bad expansion valve or something like that. Your symptoms sound to me like either bad relay or bad compressor clutch (though that can be a little pricey, especially if a compressor is needed.) When electrical things start to fail, when they heat up they can stop working intermittently. Just need to know if that compressor is running or not when the AC stops working.

Just rule out the cheap things first.
 

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Why? Way cheaper and easier than a bad expansion valve or something like that. Your symptoms sound to me like either bad relay or bad compressor clutch (though that can be a little pricey, especially if a compressor is needed.) When electrical things start to fail, when they heat up they can stop working intermittently. Just need to know if that compressor is running or not when the AC stops working.

Just rule out the cheap things first.
Ah I see what your saying.
Have always been weary of electrical. Its not something I have good exp working with.
 

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Just get us an answer to the question about whether the compressor is running or not when it turns warm. That will give the direction we need.
 

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Hey all,

I am having a strange to me AC issue. My car is 07 FG2, 142k atm.

It will sometimes blow cold, but will always turn hot.

Example
Start my car, car warms up, turn fan speed to max, hit the ac button on the dash, AC is cool. As I start to drive, AC gets colder. After driving for 20ish minutes, AC blows hot.

I'm trying to understand this problem, not sure why its happening like this. In the past Its either been a on or off situation.

Any help or ideas appreciated.
I agree with verifying relay switch (no. 5 if I remember right, inside engine bay), after seeing A/C compressor is disengaged. This is a $15-20 fix. My mechanic told me that they all fail eventually.
 

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Yes as John reiterated the simple stuff is the easiest to fix and often the lowest cost to repair. I wanted to caution you as well to not open the sealed system just yet. We can help if provided some good info.


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Discussion Starter #19
Hey all, turns out, it was the relay.
As the relay would get "hot" from use, it would fail. Changed out, AC is pumping like brand new!
appreciate all the input and advice!!
 
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