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Hi guys. My wife and I share a 99 Civic LX. I'm not too mechanically inclined, but I've done a few things like change timing belt, water pump, gaskets, and other routine maintenance. I need to buy a second car for college. A friend is selling her 98 Civic LX and I thought, "What luck!" It's only got 126k miles and it's in good shape. It blue books for about $2500, and she's selling it for $2000. Problem is, she says that a mechanic told her it "needs a new AC compressor." I live in Houston, Texas where it gets HOT, and AC is definitely vital here, especially since this will be the car my wife uses and I gotta make her happy.

So having never worked on AC stuff, I'm not sure how to approach this. I realize there are several expensive components involved in the AC system, such as the compressor, dryer and clutch (though I don't know how any of them work). Next weekend I'll be meeting my friend to do an inspection on the car myself. Is there anything I can do to evaluate the extent of the damage? It seems like a good price for the condition of the vehicle, assuming this is something I can repair myself for a few hundred dollars. But I'm worried I'm going to buy something that requires repair outside of my technical ability and I have to pay a mechanic $1000 to fix.

Any advice would be awesome... I'd hate to pass on this deal if I can fix this thing myself without going broke.

 
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Maybe my question is too rambly... How about this question: if someone told you that their AC compressor was bad, how would you go about evaluating the car to make sure it's worth the purchase?

 
Rep Power: 518

The exact same way you evaluate any other used car purchase.


Prepurchase inspection by a competent, observant, and trusted technician of your choosing.

How can you KNOW it NEEDS a compressor? Maybe it doesn't need a compressor at all. Roll that checkout into the same inspection.
Ballpark estimate and subtract or bargain on the price of the car.

 
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I appreciate the reply. So can you tell me this... is AC work something that novices take on themselves? I understand that AC systems can offer varying complexity, but let's just say it was the compressor that needed replacement... if I've changed a timing belt, is an AC compressor likely within my ability?

 
Rep Power: 518

The nuts and bolts part, sure...

Doing the (what I consider) proper thing with refrigerant, no....but that sure doesn't stop other DIYers.


As a professional, I cannot discharge refrigerant into the atmosphere.
Legally, I must use the proper equipment and procedures to reclaim/recover the refrigerant prior to opening the system.
The DIYer is free to do as he pleases though. (Kinda pizzes me off that it works that way, you don't have to follow the same rules I do.)

Then I fully evacuate (using a micron gauge), vacuum leak test, and recharge the system (by weight) after repair is completed.







The quick list:

Remove freon

Disconnect the belt.
2 hose connections.
wires,
4 mounting bolts,
(Make sure to replace the O ring on each hose fitting or it will be very likely to leak. Most parts stores should have a large selection of AC Orings, take your old ones in and match them up.)

Calculate oil needs and add, reassemble system.

Evacuate system, leak check, and recharge


HTH

 
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That's some great input, thank you much... I'll look into some DIY guides and will consider giving it a go.

I have one more question that you might be able to answer... The entire automatic transmission has been replaced. It has about 6 months of warranty left, but at 126k miles, it seems like that's a pretty extensive repair for such low mileage. Could a premature transmission replacement indicate a history of aggressive driving / misuse of the vehicle?

Thank you again. I'm super poor and want to avoid buying a lemon.

 
Rep Power: 518

I can't say much about a 99, but IMO NO, it does not necessarily indicate abuse, and no, that's not all that early on many cars. (Be glad it's not a Chrysler.)
Hondas' automatics have been kind of a weak area for an awful long time. Google it.
It can't be a lemon. That car is used, and got itself that far.

Spend WISELY.

AFAIK, only like 2 states have any regulations covering "lemon law" on USED cars. In all other states, Lemon Law can only apply to NEW cars.



(Canned reply here)
Used car window stickers say AS IS, not AS IF.

You are buying a USED CAR. You are buying any problems it has too.
That's why I always say to have a competent pro do a prepurchase inspection. Spending $100 there might keep you from making a $3000 mistake. Or $30k, whatever.
If not, then you SHOULD know what to expect as far as immediate needs. (But we CANNOT predict the future!)

If you don't want problems, buy a new car with a warranty.

HTH

 
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Lol what doesn't **** you off ezone. And ac is not hard just got to get the right equipment and tools and you are ready to begin reading how to DIY. Make sure that the equipment has a freon catch tank so you can dispose of it properly. Or expect retarded dogs and cats dead in your work area.(same as green coolant). If you have someone work on it make sure they are legit an not taking advantage of you.

 
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There's a lot of stuff that doesn't.
But it's probably a short list.
Mostly stuff that doesn't involve uninformed decision makers.
Some days I work in a Dilbert comic strip.

 
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Lol tell me about it. I work on school buses and there are too many idiots ere

 
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Hey, thank you guys for the replies. I was able to check the car out this morning, and I got some more info about it. Basically per the owner, the AC does not put out cold air, and when she turns it on, it drops the engine RPMs heavily. Could that mean the clutch is also bad?

I imagine people probably post this stuff periodically, but perhaps someone could let me know if this is a bad deal. The car blue books at $2500 (with functional AC of course), and she's willing to sell for $2300 because of the broken AC and missing stereo. I was thinking mentally I wouldn't pay any more than $2000, but I don't want to lowball her since she's a classmate of mine. I realize no one can make a decision for me, but I'd be interested to know how much one would guess this AC issue depreciates the value from blue book. Is a $500 discount a fair offer, given the uncertainty of the issue?

Thanks so much for any advice.

(PS - I'm somewhat a treehugger, so I will definitely dispose of any freon in an environmentally-friendly manner if I decide to purchase this car and take on the AC myself.)

 
Rep Power: 518

I'd want to see it firsthand. The severe RPM drop might not be severe at all, or maybe it really is.

An AC compressor turning on creates a load on the engine, so there should be a little sound and possibly some RPM change......BUT

If the compressor is locked up, that would certainly try to kill the engine. Cost to fix something like that could run all the way up to a complete AC system replacement. Depends on the extent of the damage found.
Irrelevant at this point, but it sounds like the clutch part is working.



I don't do numbers like this. (I won't even add up the estimates for fixing the cars.)
I personally wouldn't buy it unless it is a killer deal ($500 or less LOL), knowing what the cost could potentially be to make it a $2000 car again. Not including labor.
The last car I paid money for (before the current 12 Civic) was a 1990 Olds Calais (w/50k miles) I dragged out of a wreckers yard for $100 with a blown head gasket (Quad4 engine), had sat for a couple years with coolant in the cylinder. Made it a running, driving unit with license and title for about $600. Kept it for 10 more years.

No car here is in excellent condition, I'm in the rust belt.

http://houston.craigslist.org/cto/3859624259.html
http://houston.craigslist.org/cto/3830078171.html --(Claimed EX, this is a DX. Knock $5-800 off the top.)
http://houston.craigslist.org/cto/3859487040.html
I bet you could drive away in at least one of these for $2500 cash.

 
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ezone, you are awesome. Thank you for the great reply, and for also showing me what I could get in the area for a good price. I did end up buying my classmates car, but I was able to negotiate a great price due to the feedback you gave me. So now I'm trying to figure out where to go from here.

The classmate I purchased it from is the first owner and has a complete history of every service ever performed, which is pretty convenient. So I'm trying to figure out where to begin with the AC issue. I know there are plenty of guides on replacing various AC components, but I am not exactly sure which components I need to replace, and would prefer to avoid the shotgun approach. I turned on the AC while idling and I definitely hear a loud click upon starting it, and it does actually blow some cool air. Additionally, I didn't notice the RPMs drop at all. Per the detailed history I was given, the AC compressor and accumulator was replaced in 2010, about 20k miles ago. Then the AC was recharged in 2011. Then it says AC condensor replaced in 1/12, followed by an AC compressor replacement in 8/12. There's no way the condensor could have been replaced 2 times, as recent as less than a year ago, and need replacement again, is there?

Anyways, any thoughts would be amazing. I plan to work on this car over my upcoming break from school and plan to purchase the right parts and tools in the meantime. Thanks so much for any help!

 
Rep Power: 518

Sure. If you have idiots working on it, installing the cheapest parts known to science.
It all depends on what actually happened, and you will never get that part of the story.
Grenade one compressor, it can ruin the condenser. Drier (accumulator) is standard replacement item.
Grenade the next compressor, do it all over again.
Install cheapo reman compressor (guaranteed to leak), do this every damn year for the rest of the cars existence.


Fix it right the first time, it's not cheap but should last the rest of the cars life. Until the next freon leak is ignored and serviced improperly. (Lost PAG oil was not replaced when serviced? Compressor won't last long.)

If a compressor fails:
Depending on the type of failure, sometimes it sends debris throughout the system.
If it sends solids, they can lodge in components downstream. Large solids don't normally get past the expansion valve, but tiny solids sure can (metal flakes and black death).

If it melts teflon seals out of the compressor, that stuff not only gets into the condensor, it can remelt and continue moving downstream whenever the system heats up again. HUGE problem.

If the compressor ground itself to death, it can leave what we call "black death" ALL throughout the entire system. (Google: black death.) Fine powdery blackish residue. It can and will ruin the next compressor, this is why I said to expect "all the way up to a complete AC system replacement. Depends on the extent of the damage found."




Normal!
PLUS!!
What did I tell you earlier? LOL

Since you say it DOES cool some, I'd start with hooking a set of gauges up and checking pressures while in operation.
If it only cools weakly, I bet the freon is low again or the expansion valve could be clogged with debris, or something..

Connect AC gauges, both high side and low side.
Grab a thermometer, stick it in the center dash vent.
Run the engine at 1500 RPM, blower on full blast, MAX cold, recirculated air.
Let the system stabilize.
See what temp is, see what pressures are.
Compare to pressure charts.


Or, you know, have a pro check it for leaks and refill it?

 
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Thank you for the reply. I only mentioned the RPMs just because I thought it might be pertinent info since starting the AC isn't drastic enough to stall the engine or anything... As for the click when turning on the AC, it's pretty loud. I do hear a click on my other car (a 99 Civic LX), but not as loud as the click on the newly-purchased 98 Civic. I looked up black death as you mentioned, and that's definitely a scary prospect. I'm hoping the problem is simply non-OEM parts. If I isolate the problem, I will definitely replace with OEM parts only.

I will check the pressure readings as you say. I noticed there are a ton of AC gauges on Amazon. Anything specific I need to look for? As for the thermometer, are we just talking about a glass mercury thermometer?

Thanks again... if the problem gets too complex, I will certainly take it to a specialist. I'd definitely like to learn how to measure / refill ACs though since I now have two Civics.

Edit: Autozone carries the gauges, and it sounds like I just need a glass thermometer to stick in the vent.

 
Rep Power: 518

Gauges and pressure readings can indicate to me if the system is full or not, and other things that might be going on inside.

ANY thermometer that will accurately read vent temps, one from a refrigerator is ok. Unless you have a calibrated hand and can tell when the air temp gets down to 38-44 degrees F. Most people can't tell the difference between 40 and 65 degrees when it's 100+* F outside.
I thought Mercury thermometers were banned now?

I have a couple of kinda cheap digital units, they get the job done.



I have to be accurate when I do something, I can't afford to guess (much) for a paying customer.



I really can't give you a crash course in HVAC theory here man, you need to do the research yourself if you really want to learn it.


If you get to refill your own, make SURE you only use pure R134a, nothing else. All other refrigerant stuff is considered a contaminant and you could be rejected by any shop that cares about their expensive AC equipment.

 
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Hey there. I'm finally on break from school and had a chance to hook up an AC gauge and thermometer. It's about 95 degrees today with about 60% humidity. The readings were taken in the shade following the directions in the Honda service manual. I took readings on both my 98 Civic (the one that I recently purchased where the previous owner said "the compressor needs replacement"), as well as my 99 Civic just for comparison. Here are the readings:

98 Civic
- Temp: 60 degrees F
- High pressure: 205
- Low pressure: 34

99 Civic
- Temp: 45 degrees F
- High pressure: 200
- Low pressure: 27

Do these readings indicate anything in particular? I'm having a difficult time wrapping my head around the Honda AC charts, but if I understand correctly, the 99 Civic may soon need a little extra R134a, but I don't know what the readings from the 98 Civic could mean. I will say that the air coming from the vent in the 98 Civic seems a little humid and has an interesting smell... possibly a leak? Any advice would be extremely helpful... thanks!

 
Rep Power: 518

Were these both done with the engine at idle? Try holding the RPM at 1500 and see if there is any difference.

Does the water valve still work----is coolant still flowing through the heater core? I have seen plenty of heater water valves that appear to work visually but had in fact rotted away underneath the cable and lever. Lever moves but water flow is not shut off.

The 99 doesn't look too bad at all if it is 95 degrees out. If you are comfortable with how cold it gets while driving, then I'd say to leave it alone for now.
The 98- did you have that set on fresh air instead of recirculate?


Ok lets gather some data/numbers I can plug in to a chart.....
Set up the car.
Park in the shade. All windows open, doors wide open. Hood open.
Thermometers: One in the center vent (Ideally one for each dash vent), and the other in front of the blower recirc inlet (I stick it over the top edge of the glovebox on most)....the idea here is to measure air temp before and after the evap core, to see how much the AC can drop the air temp in a single pass...
Set controls to max cold, dash vents, and recirculate.
Turn the AC on, fan speed to full blast.
Using a throttle prop, hold the engine RPM at 1500
Let system run for 10 minutes like this to stabilize
Take temp readings from all vents
Take temp reading from blower intake
Need ambient temp, humidity, and system pressures, all while running at 1500 RPM.


For the 98 I made up some numbers to plug in just for an example....
60*vent temp
85* blower inlet temp
60% humidity
95 ambient temp My chart said the 60* vent temp could be acceptable, (that would be a 25 degree drop across the core) but when I plugged in the pressures it said the high side is far too low given the rest of the conditions.

Again, I just made up the numbers to plug in so this can't be considered accurate yet.

Plugging in the numbers from the 99 didn't work either.
I'm thinking both are undercharged right now.

 
Rep Power: 0

Thanks again for all your help. I can’t say it enough. I’ll reply to a few things in your previous post. Both cars had pressures and temperatures measured at 1500rpms, in the shade, with windows and doors open, the hood open, AC on full blast and set to recirculate. The temperature I took was from the center vent.

You mentioned obtaining a second temperature… are you saying just stick a thermometer into the defroster vent above the glovebox near the windshield?

You also mentioned making sure the water valve works. Do I just verify this by looking into the radiator while the car is on? I’ve drive it around a fair amount and haven’t overheated at all…

Finally, you had mentioned that both may be undercharged. How do I find out what the correct refill pressures are? From my understanding, the low side pressure indicates the coolant level… do I just fill until the low side reaches a certain temp?

Thanks mucho!

 
Rep Power: 518

Not the defroster vent.... I'm looking for the temp of the air being sucked into the fan when the controls are set to recirculate. That's the blower inlet temp. If you could open up the glovebox all the way (til it drops to the floor) you'd probably be able to see where that inlet is on the blower housing.

The grate with brown foam showing is the inlet when the driver selects recirculate.



No. The water valve controls the flow of hot antifreeze to the heater core. Flow is supposed to be shut off when the temp control is set to coolest position. If the heater core still has antifreeze flowing through it at 180 degrees, that will greatly affect the temp at the vents when the AC is running. You have 2 very similar cars with very similar pressure readings but quite different vent temps. I was trying to give you some possible ideas as to why the big difference....besides just freon. And at the same time figure out if it is a freon problem.

Contrary to popular (and management) belief, not all AC issues are from low freon!. Heater core still hot could be a biggie.



I was trying to get temperature numbers taken from specific places and under specific conditions so I could plug them into this program I have here.

I charge AC by weight (we have one of those big recovery machines at work), but I use performance, temperatures, and pressures to determine if the system is working fairly efficiently or not. Charging by weight is the most accurate way to do it. There are SO many variables that go into pressure readings that the average Joe with no experience has a slim chance of getting it right.

Plus, the AC systems are so small, there isn't much room for error. A few ounces over or under spec is all it takes to suffer a loss of cooling performance (an example of max/min spec is 0.40 Kg to 0.45 Kg, or 1.75 oz. leeway in charging....and 0.45Kg is not quite equal to a pound.) Most average DIYers will try to stuff a whole can at a time in without having any way of knowing what the high side pressure is while they do it. Then wonder why it still doesn't cool good.

Feel the AC suction line coming out of the firewall leading to the compressor. Under the same conditions as before, How cold is that line on each car?

Feel the heater hoses (between valve and firewall) at the firewall on each car. Any big difference? (I use infrared temp gun here. Feeling the heater core itself isn't normally possible.)

It's awful hard to give a crash course in how I think and how AC systems work. There's plenty of info on the net about it if you are willing.

 
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Hi guys Im in the Same BOAT...Im Also in Houston...just changed out the DRYER, Expansion Valve and compressor last week...$185 from Buyautoparts(seemed like a good deal for not reman-ed parts)

2000 honda civic

my readings were..

49 Low psi (Civic chart says im in the ban )
250 High psi (Chart says im LOW not in ban

95 temp (outside) 80% humidity
60 exit temp

Wife's- PILOT(2004) is getting to 50 temp -- 10 colder

Im worried that my High PSI is low...the Civic chart I have says it should be around 330 PSI (H) for the outside air temp...what would cause that ? too much Freon? PUT almost 2-12 oz cans in.specs say 21.9-22.1 oz.
Should i be worried or am I ok ?
Anyway do not want to HIJACK thread...but figured we are on same problem.

A Side Note...the PIC posted... there is no Filter there(at least on mine) that door just opens If on RECIRCULATE. Is closed like pic shows for outside air. If filter gone(not sure there is one just looks like one in PIC) the Fan and Evap will be clogged full of Carpet fibers like mine was.
Could be your problem.

AP514

P.S. Putting in my 2 cents to work on a final goal...COOL AIR for the car

 
Rep Power: 518

AFAIK, US Civics did not get a cabin filter until 2001.

Too much freon will not cause low pressure on the high side.

What is the vent temp while driving down the road?

Temp taken while set on Recirc or Fresh?

Temp taken while at Idle or 1500 RPM?

Sorry, it's awful tough to evaluate AC from long distance.

 
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sorry the temps I posted were while driveing.....I did not have the temp gauge while I had the Gauges on the civic.(got the cheap-o temp gauge local from parts place).

I will post a set of serious numbers within the next few days..

1500 RPM, in shade, recurc windows open, in temp, out temp..Low PSI , high PSI


Just weird that High side from Manual is low.....looking for Causes..


Side note:Comp did not shell but was being safe...Comp, dryer and exp valve changed.. Flushed condenser w/2-bottles Alcohol(no crap found.drained into cup), cleaned evap fins, fan, added Pak 46 oil to parts in system(mostly in Compressor)...all but Dryer forgot...but about 6 oz in total. System was not left open after I put dryer on but I did not pull VAC for a day or so (Vac pump took a crap on me)
I pulled Vac for hour at -30..added about 2-12oz cans Freon hard to judge exact amount..think about 2 oz left in can.


AP514

 
Rep Power: 518

Sounds to me like it is still undercharged if the high side is that low, given the high ambient temp and high humidity. (My chart gave about 310-340 PSI---but I plugged in some random numbers so it may not be all that accurate).

Did you let the cans suck while the system was running? Raising RPM while can is connected (low side pressure drops) may help get more freon out of them. (You can't get ALL of the freon out though, since the low side is a positive pressure.)

The AC is not very efficient when the engine is idling, it gets more efficient as RPM increases. Pressures change, low side may drop and high side may increase. Take your pressure readings with the engine at 1500.


Also, the Civic system is small, you have a lot of heat load, and lots of humidity that have to be overcome before effective cooling can occur.



SO now I tried to plug in your numbers into my chart, but I have to guess at some...so this isn't accurate. But it may be close.
The numbers I used were
60-vent temp
88-blower intake temp
80-humidity
95-ambient
At this point the chart gave the 60* reading as acceptable, that would be a 28 degree drop in a single pass across the evap core IF the readings were taken as directed.
49psi was ok,
250 was low.

 
Rep Power: 0

thanks for the Reply ...the vent temps I posted were Rec on Windows up....going down road...the wife's Pilot was 10 cooler than the civic...both tested about 20 minutes apart.
(so about same outside air temps) the outside air temps was in shade

You think there is not enough FREON in the system ?? I am worried about it sucking too much in...can to much blow seals on comp ? and cause other troubles ?? im just use'n a hand held can and a gauge from the parts store not the good gauge set...I do not have the adapters to punch can and hook to yellow line -ATM.

Going to check PSI's and temps at 1500 RPM first thing in morning......

So can I over service by just holding the can.?
PSI is good for low side and temp....

AP514

 
Rep Power: 518

The first thing you would see if overcharged is high side pressure far too high.

It is easy to overcharge the system if you don't know what you are doing. Watch the high side pressure while charging.

Monitor pressure, monitor temperatures the entire time.

Do not just connect another can to it if you have no way of regulating it or stopping it. It sounds like you probably only need a few more ounces, much less than a whole can.

This is why we charge by weight, using a big machine. Much simpler.




Ever thought about connecting the gauges to the Pilot to see what it's pressures are running in these conditions, for comparison?

 
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Well,Here is the temps finally rigged up a throttle...RPM's are 1500 ouside temp is 90 (8AM dam it is hot in houston) grabbed another 12 oz can and an adapter for the can to hook can up to the Yellow line on my service kit. ran engine for about 5 minute AC on rec, high fan and windows down. low side was low around 25 psi high side was 250.... put another can in..and it really took alot(almost half the can if not more)..might have over charged it...
NOW H PSI jumped up to 430... L PSI is 35psi...air is coming out colder...But now low PSI is low on chart and high is ok/high....So ran down the road and back...temp from AC w/ windows up ,rec on and fan high, got just below 60....

If i wanted to let some Freon out could I just crack the High side line going to Gauges while engine running and Ac on to let some bleed out ?

OR just hook VAC pump up and pull a VAC for a few seconds......or do I have to start over from Scratch and pull a full vac...


Update rehooked gauges after a few hours sleep... and of course things are changed......45 psi onlow side and high is about 280 PSI....high side guages bounce'n now. cycled ac and gauge settled down but still bounce'n about 50 psi as it is running

 
Rep Power: 518

Hitting 430 was way too much. That is getting close to the cutout pressure.
That's why I said to monitor pressures and temps while charging.

You can let freon out from either high side or low side, it's the same freon. The engine does not have to be running......but the only way to check pressures is to run the system.
When you vent a running system, oil escapes along with the freon.

You can trash a vac pump by connecting it to a system that has pressure in it.

Gauge bounce might have everything to do with location of the test port.

 
Rep Power: 0

Interesting thread. I was going to recharge my 2004 civic system with standard can of freon but my gauge said it was way to high of PSI on the low side. I just pressed the valve and let it out until the pressure was right. Im still blowing hot air and the air coming out of the valve was warm. I had no idea I was releasing harmful things into the atmosphere. Can some one confirm this?

 
Rep Power: 518

If you did this while the compressor was not engaged and operating then your AC system is now nearly empty.

Absolutely, you were releasing harmful chemicals into the atmosphere.

---
No offense to you personally here, but I really HATE that stores are willing and able to sell freon and freon substitutes to the general public, while people like myself are subject to laws, regulations, rules, certifications, and licensing in certain locations. I believe everyone including Joe Blow DIYer should have to follow all the same rules and regulations the professional has to adhere to.
/rant