General engine questions/issues that aren't specific to the other categories
User avatar
By Leppy
#313422 Ok, i've got an issue with my A/C. I generally know what i'm doing, but I don't have the equipment to troubleshoot or the money to take it to a shop for this without a gameplan. That, and I've worked at Honda for 4 years, having to take my car to a shop would be a blow to my ego lol. I want to get some educated talk on what's going on.

Anyway, onto the issue. The temperature only get's mildly cool, about 70 degrees or so under normal driving. When it's cooler outside and the motor isn't heatsoaked, it sneaks down to about maybe 65-ish. Setting up my little cheap-o pressure gauge shows it's got pressure reading 'full', but i can't tell you how much is in there exactly. When I WAS working at Honda when we put the B18C in, we added dye to the system, and there are no visible leaks in the condenser or on any of the o-ring locations. Last I looked, the window was frosty colored when it was running and holding about 1500 RPM on full blast.

I, however, do NOT remember if we changed the dryer when we swapped everything over (2 or 3 years ago). It's the D-series compressor, converted to R-134, and we put it under vacuum, added oil and charged it according to the EG D-series service bulletin.

We built the car (B-swap, mild restoration, etc) for my coworker's dad, and he drove it for a year before he sold it to me. The A/C belt was loose when I got it back and was squealing. That was fixed by a simple adjustment at the beginning of this summer, and it's been only mildly cold since. I have no idea if he added a quick walmart/autozone refridgerant charge or not when he had it, but i wouldn't put it passed him.

Also, when parked out of gear and the motor is hot, the compressor kicks on and off in a matter of about 15 second intervals for a little bit, then behaves for a bit.

So, Is it undercharged? overcharged? Air in the system? Would the dryer be causing this? Any ideas?
User avatar
By Leppy
#313435
bigJOE671 wrote:Read my post:
http://civic-eg.com/viewtopic.php?t=24711

But I suggest your recover the freon, do a vacuum, and recharge. Don't forget to change the dryer.


I actually read that a few weeks ago when i was trying to figure it all out. I know mechanically how it all works, just want to see what the general consensus is on the problem.

I'm leaning toward some air in the system. It's the only reason I can see as to why the compressor is being finicky.
User avatar
By elrompetoto
#313438
bigJOE671 wrote:Read my post:
http://civic-eg.com/viewtopic.php?t=24711

But I suggest your recover the freon, do a vacuum, and recharge. Don't forget to change the dryer.
i second this
User avatar
By bigJOE671
#313440
Leppy wrote:
bigJOE671 wrote:Read my post:
http://civic-eg.com/viewtopic.php?t=24711

But I suggest your recover the freon, do a vacuum, and recharge. Don't forget to change the dryer.


I actually read that a few weeks ago when i was trying to figure it all out. I know mechanically how it all works, just want to see what the general consensus is on the problem.

I'm leaning toward some air in the system. It's the only reason I can see as to why the compressor is being finicky.


All right...your compressor turning on and off could mean a couple things: Your high side is reading to high of a pressure and hitting the high pressure switch...maybe too much freon :? , blockage in the condensor :? , or too little freon(freon gets low over time) and hitting the low pressure switch :? Also the possibility of air in your system being introduced by hooking up guages or trying to put more freon in your system

The only real way to diagnose is to hook up guages and read the high and low pressure. A cheapo gauge ain't really gonna cut it. I'm assuming you know that. Maybe a local shop can read your pressures for no charge if they offer it.

I bought my gauges from Advance Auto for like $90. I didn't even intend to return it or use it to make profit. But that was the price I paid to do my own AC system. When I first did my AC...I got the vent temp to 42-45 degrees fahrenheit on an 85F and 40% humidity. Just by following the posts on HT. Now my vent temp is 50 degrees on the same day conditions :? IDK why
User avatar
By Leppy
#313442
bigJOE671 wrote:All right...your compressor turning on and off could mean a couple things: Your high side is reading to high of a pressure and hitting the high pressure switch...maybe too much freon :? , blockage in the condensor :? , or too little freon(freon gets low over time) and hitting the low pressure switch :? Also the possibility of air in your system being introduced by hooking up guages or trying to put more freon in your system

The only real way to diagnose is to hook up guages and read the high and low pressure. A cheapo gauge ain't really gonna cut it. I'm assuming you know that. Maybe a local shop can read your pressures for no charge if they offer it.

I bought my gauges from Advance Auto for like $90. I didn't even intend to return it or use it to make profit. But that was the price I paid to do my own AC system. When I first did my AC...I got the vent temp to 42-45 degrees fahrenheit on an 85F and 40% humidity. Just by following the posts on HT. Now my vent temp is 50 degrees on the same day conditions :? IDK why


That's pretty much my train of thought too. I've done A/C work when I worked at the dealership, but it wasn't my strong point. If I didn't live 4 hours away from there I would have already done it on a saturday off the books with help, but that's not an option anymore. I really wanted to make sure I was on the right page before I found a shop to go to. I hate going to a shop for something I can do myself but I might not have a choice. Just didn't want to go in without an idea.

Thanks for your help.
User avatar
By Leppy
#316005 Found the issue. The larger valve has a minor leak that's causing it to only compress up to a certain pressure before leaking out, which explains the odd behavior. It all makes sense as to why it only get's cool but not cold and misbehaves when it's hot.
User avatar
By bigJOE671
#316030
Leppy wrote:Found the issue. The larger valve has a minor leak that's causing it to only compress up to a certain pressure before leaking out, which explains the odd behavior. It all makes sense as to why it only get's cool but not cold and misbehaves when it's hot.


I'm glad you found the problem...I hate gremlin issues.