Honda Accord A/C Question

Since the Beeb always comes through with about everything else, I figured I'd ask for help on diagnosing the boy’s A/C issue with his car.


2008 Honda Accord Coupe, 3.5L V6, EX-L (no nav)


A/C was only blowing hot so I checked a few things, tried adding freon and it wouldn’t take. Figured out the compressor clutch relay was bad, replaced it and boom A/C works sitting in the driveway. Add a little freon to it and with the windows down it’s blowing ice cold. Fast forward a day and now it’s blowing hot again going down the road but sitting in the driveway with the doors open it seems to be blowing cold air to me but 5 minutes down the road it’s like the heater is on.


Any idea what I need to check? I thought about order some gauges and making sure pressure was ok in the system but after that I’m stumped.


I don’t mind taking it somewhere if I need to but I’d like to try and fix it myself if possible.



Thanks,


Brian

 

I stayed at Holiday Inn express last night. My guess is leak(s) in system or possible evaporator failing (or both).

 

System had Freon in it still but figured after 12 years it needed topped off.

My fear is the expansion valve has crud in it and isn’t working correctly. To change that I have to go through the tail pipe to get up under the dash. [emoji849]

 

Get the gauges.

You can "borrow" them at the major auto parts stores.

 

When the Accord is at an idle with the A/C turned off and you turn it on, can you hear/feel the compressor kick on?

 

Yes, now that I changed the AC clutch relay.

 

Call you dealer for an appointment ......and then buy a new car

 

You might have overfilled the freon. I had to replace the compressor in my car. Rented the AC vacuum and filled it myself. My cheap ass gauges apparently wern't accurate enough. Sent it to a local shop and they charged me about a hundred bucks to diagnose and drain out a little gas. Still saved almost a grand by buying/replacing the compressor myself. Go to autozone and rent the gauges.

 

Not happening for my 16 YO. I just bought a brand new AT4 Sierra less than a year ago, he has to drive that thing until he’s done with college or buys his own car.

 

Assuming it's serviced correctly and not leaking, Honda's have a compressor overtemp switch that will cause that issue.

 

The first thing I would have checked at the beginning was whether the fans on the radiator turned on when you turned on the A/C. Obviously they did, which says that there was enough Freon in the system to engage the A/C. The first thing I would have checked was the clutch relay, which you did. These cheap little units are made in Viet Nam and tend to fail in both directions. (Open, causing no cooling, closed, draining battery and/or compressor engaged without fans, causing high pressure.) When I go to the parts counter, I simply ask for a "FUBAR Relay", they know what I want.
A/C operating OK while idling in driveway but not while driving? Since it probably wasn't working for a while due to the relay, first thing I would do is get that sucker up to temperature, then run it at about 3,000 RPM with the A/C on. Observe the clutch engagement when it cycles. It should engage immediately and forcefully at the same time the fans kick on. Watch for delayed engagement, dragging, or not engaging at all. If I get it not engaging, I'll take an old trunk lid spring (A 3 foot screwdriver will work, too. ) and carefully place it against the driven plate to determine it there is magnetism at the plate. If you can feel it the gap is either too big and/or rusted. Many options here. Replace entire compressor/clutch assy with a reman, (Honda makes them for certain models, aftermarket doesn't thrill me too much.) R&R the compressor and replace the clutch assy, checking the coil while you have it out. On some shitboxes not worth the money, I've pulled the driven plate off, wire brushed the surfaces, removed all the shims and put it back together.
Contrary to beechkingd's post, there is no compressor overtemp switch. There is a physical blowby switch to handle too much pressure. Make sure your cooling system is OK. If the ECT sensor (Engine Coolant Temperature) goes outside its normal parameter, the computer will shut off the compressor.

 

Drop it off at your local independent tech. Mine charges $90 for an A/C service. I’ve been standing there while he works on other people’s systems and it’s amazing what he can tell by watching that machine’s display and how the system is acting. It pulls a vacuum, which will indicate any leaks. Having an excellent mechanic look at it is an investment.

 

There is one on an S2000 I've changed it. Assumed all of them did. I was wrong.
https://www.amazon.com/Genuine-Honda-38908-PCX-006-Thermal-Protector/dp/B00AQUWEOY

 

Different models have different setups. I was replacing thermal protectors on 2001-2005 Civics like it was nobody's business.
Having access to ISIS, I was able to look at the official schematics for the Accord. As far as the actual A/C clutch, I haven't seen much of that on Accords, but plenty on 2006-2011 Civics and CR-V's.

 

First things first, charge the system to the capacity, this is ONLY done correctly by weight, then continue diagnosing. A/c clutch coils can get hot and gain resistance and not be able to engage the clutch much or at all. Definitely a lot of different scenarios can play out. Even then it may be nothing to do with the compressor, it may be your temperature control/ HVAC ducting etc...

 

Real men don't need A/C.

...your wife on the other hand.

 

There is a really good possibility you overcharged it....
Those have a lot of issues with the dryer stopping up also causing the same issue.

Really takes a skilled tech to add Freon and get remotely close to the right amount in newer small cars, they hold less and have a smaller window for what will work volume wise. It has to be a warm to hot(85-95) day where the system will be loaded, inside fan on high, Recirculating switch off. Low side pressure should be around 30psi and high side should be over 200 but under 300, with the condenser fans on high. Most importantly, the low side line should be cold all the way back to the compressor. That means the evaporator is flooded and the system is full. If it isn’t the system is low.....IF it is circulating.
If the pressures are off feeling the lines can lead you to the problem, the liquid line(small line) from the compressor to condenser should be hot, if there is a big difference in temp going in and coming out of the dryer that is where the issue is. If the line from the condenser to the evaporator is cool that is a sign the condenser is stopped up.

Good luck.

 

Hooked gauges up tonight and it definitely has too much Freon.

Got the low side down to about 40 and the high side at 210.

Air temp was right at 55 coming out of the vents while sitting in the driveway. Went for quick spin and the air temp came down more.

I’ll see how it fairs over the next few days. Worst case I have the system fully evacuated and recharged to a precise volume.

Thanks for the help everyone.

 

I've noticed after charging a system it takes a good 5 miles of driving before a system will come around and cool to it's max potential. I'd always assumed certain parts were flooded with liquid that needed to be circulated through, seems plausible.