2001 Mazda Tribute A/C issue

2001 Mazda Tribute V6...just had tranny rebuilt to the tune of $2800...OUCH. Just doing local driving since then...no issues. Hopefully this might be a simple fix. Went to Las Vegas Friday and when we got in a hillier area lost some a/c cooling. Not like it was off...just cool, not cold. Seemed to subside once we were running slower on flatter roads. Saturday on the way back would completely shut down going up long or steep grades. I'd just turn it to air til we cleared them and got back to the flatter stuff. Would come right back no prob.

It was pretty hot both days (mid-90's) and we were driving at about the same time of day. Main difference was the roads and we were heading into the wind coming home. If I slowed down to 60..seemed like it didn't happen quite as much, but can't be sure.

Wife also stated it seemed to happen to her when she was driving up to hike a mountain park on Thurs. Very steep road, but it wasn't hot and her speed was probably 35-40 MPH max.

No sight glass so can't look for bubbles or anything. Engine temp never climbs past normal (not normal range!). It gets to operating temp and stays right there...never changes. We have the aux cooler since it has the towing package (all 3000 lbs of it...lol) and the cooling fan works fine.

Never an issue in around town driving.

So..what would the possible issues be. Low charge? Worn Comp (oh please NOOOO). Could the fact it seems the engine is a little down on power cause an issue? No engine codes or CEL or anything though.

I know I'll prob have to try and find a shop no matter what...since I think my gauges are for R12 and this is 134a.

Thx

 

well, i'd tie it into engine getting tired, maybe slightly low freon, and apparently going uphills. you go up, your speed drops down, and engine is getting strained, right? comp takes a lot of power to move freon, you know that.
start with 2 things.
1. pressure wash your radiator. it might be clogged some, so it does not permit full air flow
2. check or replace either a/c or serpentine belts.

is a/c fan kicking in fine? are the air flow actuators working fine? is your temp dial set to cold, not to "slightly warm"? Ford had their hands on those, and the dials gears in climate control, if you pop them open, are prone to all kinds of problems inside, due to cheap plastic used. i don't think they ever changed it since my so much infamous 87 Taurus.
comps are very simple devices. unless you do run them w-out lubrication(read - low freon/oil mix) they run long times. clutch might be slipping some, but it's a service item.

btw, why you didn't DIY trannie? they are around 7-800 refurbished with warranty, half day 2 men job to swap. or from salvage yard.

 

I'm out in the middle of the desert and didn't have much choice. It pretty much took everything out. TC, valve body, solenoids, bands, etc, etc. When it first happened I was 80 miles away from home and really had no choice...so I kept going even with the light flashing. Had a thread I started on it back when it happened...18 months ago...lol. When it was out of commission, I'd start it prob 2 times a month and run it for 30-45 min or so with A/C for 1/2 and heat on for 1/2. Just to keep stuff moving around.

I actually checked a few places for availability and most were around $1400 just for the trans...not incl freight charges (or TC in some cases). That's what I paid for the parts needed..so thats kind of a wash. And this shop installed the kit that fixes an apparent issue with line pressure(?) in this application, a couple of places I called didn't know what I was talking about. Buying a tranny gives me a warranty on the trans...but not labor. This is nationwide warranty for all of it. No...not AAMCO...lol. Besides which, I'm past the point where I'll do much more than a brake job or normal maintenance. Knees, shoulders, and back just won't take it. Maybe a manual trans on an older car...but not in a newer one with the nightmare of stuff that has to be removed first. Jeez..just changing the plugs on this is a $350 charge.

As to your A/C questions...yes, all those dials work and air blows strong where it's supposed to. Fans all do what they're supposed to as well. After startup as soon as a/c is turned on, rad fans kick right in. Radiator has some bugs in it...but not blocked at all. I'll have to look at belts and tensioner.

I'm thinking after 11 yrs, even a tiny leak may have let some out. I seem to remember it doing it once or twice a few years back when I had a full load of in-laws onboard...was even in the same area of the road coming back from LV.

 

Here's something I always wondered about. Home a/c systems..the comp runs at a constant speed (at least most do I think). How do cars do it with all the varying speeds from 800 to maybe 4000 rpm...and it will work just fine till you do a WOT? Just curious.

 

Vic, got a 2005 Tribute with V6, and I note the air isn't as cool going up mountains, either. I have just attributed it to what ukrbyk has said. Strain on the engine to pull the hills and the compressor takes second place. Flatlands it does great. Pressure washing the radiator out would be a good choice. Just had the harmonic balancer changed on the Cummins, and all three radiators (turbo, intercooler and water) pressure washed. Big difference.

 

Well...the issue is relatively new...so that's what makes me wonder. Maybe its time to pull out my rescued PW and see if it still works after 3 yrs of no use...lol.

Won't the PW mess up the fins...or are cars tougher than home system coils? Guess they do have to stand up to a lot more. Wish I could do from inside out though.

Prob time for a rad drain, flush, and refill also...though the engine temp seems fine.

 

Gunguy, I would say you are looking at a strain issue. High temps and humidity in conjunction with the climbing of hills is a definate performance killer. As far as pressure washing the condensor/radiator, take it slow and you should be fine. The fins can take a beating straight on, but if you hit them sideways with the high pressure water you could bend them up. On modern vehicles the engine computer turns the compressor clutch relay off at WOT. So if you are at WOT long enough to see a performance loss in the A/C system that is why.
Hope this helps ya,
Billy

 

Thanks billy..
No humidity out here..thats for sure...lol. I haven't even gotten the first drop out of my home A/C unit yet...gotta water plants with water I pay for. And no WOT...I know what that does to the A/C....matter of fact thats one factor that busted the tranny, but thats a different story. If I hit bigger hills...I just drop out of OD and slow down to try to keep it from kicking down and hunting.

Anyway...just checked my gauge set and it IS for 134a. Even have a can of 134 I bought a while back for my ex-truck, in case I need it. When I looked at the car earlier...I only saw one port that seemed easily accessible...didn't look that closely. I'm sure it's there somewhere.

Any ideas on what correct pressures should be? I have the chart that came with the gauges...but I thought different vehicles had diff specs?

 

Different vehicles do have different specs, but as long as the low side pressure is above 20 and less than say 50 with high side pressures at least 150 then you should be fine. Never worked (or lived) where there is NO humidity. Its always Humid here in the South East, although I am not as far south as I used to be and the humidity here only lasts a short time for the most part.

 

this should help. basically, what it says is that pressure valve is constantly regulating system pressure vs rpms.:

The expansion valve has three points of pressure that work together to regulate the amount of refrigerant that enters the evaporator so it complements the amount of refrigerant burned off by the evaporator. The valve pressure switch receives pressure from the bulb, the evaporator and the spring. The evaporator and spring pressure work together to close the valve. The bulb pressure opens the valve. When the expansion valve pressure switch decreases pressure at the bulb, the valve closes. When pressure increases at the bulb, the valve opens.

 

i'd still drop a small can of oil/freon mix in. and definitely check 'm belts.

 

I guess PAG oil is the standard for 134?

 

don't guess. they sell premixed cans nowadays. all you need. with or without direct attachment. wallymart is best priced. ten bucks or so. still have some sitting on the shelf.

 

I didn't mean I was guessing at the type of oil....thats just what I saw canned in combination with R134. Not like diff fluids for P/S, trans and such is what I meant. All 134 systems use PAG oil?

btw..thx for the info about the valve regulating pressure.

 

Many newer cars have an A/C cutout at wide open throttle, designed to kick off the A/C when you need max engine power. I'm not sure if the cutout senses low manifold vacuum or is operated off the throttle position sensor, but its possible the mountainous driving caused the engine to labor hard enough to tell the computer to kick off the A/C. Since it seems to happen during hilly driving, but works fine on the flat road, I'm guessing this is your problem.

 

Yeah...I kind of wondered if the vacuum thing would do it myself. Never went to WOT so it made me think vacuum is involved. I know it varies...but I'm trying to remember...isn't vacuum highest when loaded at part throttle? Oops...nevermind...Wiki describes it very well.

I'll probably try to hook up gauges today...see what we get.

I'm sure a tune-up is in order...but just can't see doing it for a while. $350 just to change plugs...not including the parts needed for reinstalling the manifold.

 

So you are looking at around $120 an hour labor rate? WOW!!! It calls for just under 3 hours labor to remove the manifold to replace those spark plugs. How long has it been since they were replaced? I imagine it probably had a platinum or irridium plug in it from the factory since the maintenance service interval is 100,000 miles.

 

Last time I asked at the shop that has done work for me before, thats what he called back with. May have included parts..not sure.
Yeah...it's overdue. I changed the front 3 a while back no sweat...but I'm about 30K over for the rears.

As to the A/C stuff....hooked up gauges to check, put a thermo in the vent, low side read about 30 (w/in spec mentioned here, but seemed low according to other sources for the outside temp of 80), checked thermo since it had been running a while, little over 40. Ok..not bad right? Just stop there, right? OHHH noooo, I HAD to check the high side....

Opened the high side and got a leak at a connection on the low side hose...freon and some oil....not a lot..but some, shut off valve, call it quits. 40 is pretty much ok.

Shut off engine....let pressure equalize, removed hoses. Started engine and a/c to check for schrader valve leaks before putting cap on. Checked thermometer again...CRAP...just over 50...let it run..no change. Ok..Must need to add some to replace what I lost.

Shut it off, let it equal, hook up hose and attach to can. Start engine, tighten valve to pierce can, CRAP...leaking all around the valve. Don't hear any flow. Shut valve, shut off engine, remove hose, start engine...check valves for leakage, temp still just over 50.

I'm done....going to look for a shop. And throwing the cheap gauge set and hoses in the donate box. Single gauge, 2 piece hoses and cutoff valves down near the port end of the hose. Doubt they ever worked correctly.

Thanks for all the help...but I'm just past the frustration point.

 

super walmarts with shops used to be the best priced places for this type of job. saying nothing else, considering you are boiling right now. sorry, brother.

sounds like overall layout of your four banger is same i had on my Ranger. manifold on the driver side had to be removed to get a spark plug out. mine had 8 plugs for 4 cylinders, btw. as i am sitting here, it was maybe an hour job. but it was a pickup, they might have really crammed it in S-ute.

 

It's a transverse 6 cyl.

Never again will I buy a vehicle w/o finding out what the basic stuff costs. I did look for things like filter locations, access to most stuff, cost of certain items. I hope the cats don't fail on it...they're in the exh manifolds...something like $600 each!

Had one replaced on my Dakota...repl part was about $150 as I remember.

 

dealer wants $475 to do plugs on my wife's RX300 with transverse V6. i figured it out and did it in 45 minutes and a lot of scratches on forearms. simply removed air intake hose and throttle body, which allowed me to have access on the driver side to stick my arm in. pass side was ok. 2 cardan extensions ( I am smarter now, I have flex drives) and a lot of cassing did it. $475 in 45 minutes was not a bad profit margin on the job.

 

Sounds like you were ok before you got the leak. Tough break... What was the pressure on the high side gage before you decided to open the gage? Did you have the shaker can attached when you opened the high side valve? You will have accurate pressures without opening the gages. With stand alone gages you should never open the valves unless you are charging the system. And you should never open the high side valve with the engine and A/C running. The high pressure refrigerant can backfeed into that can and turn it into a grenade.
Walmart doesnt do service work, Only tires and oil changes!

 

now that you calmed down, gunguy... i have learned the very hard way to put my entire 277 lbs on those can attachment, when recharging systems. esp if you have a plastic attachment with bearings in it. they have very large tolerance, when made, and if not totally crammed onto the seat, they will not open the stem valve and leak out. got few frost bites that way.
sounds like instead of forcing freon in, you let most of it in the system out. sorry, old friend.

 

billy and ukrbyk...nope...didn't do any of those things wrong. Prob didn't explain it well enuf.
My gauge set has cutoffs about 6" back from the port connection, a 2' hose then screws into the cutoff and the other end into the manifold where the single gauge is attached. There's a quick connect with schrader under the gauge for connection to a 134 can. So I have to open the respective cutoff to get any sort of pressure reading or to add 134.

Where it leaked was at the low side threaded connection at the valve (with valve closed) when I opened the high side. I guess it either could take the low side pressure OK or when I was closing the low and opening the high it unscrewed just enough to leak when the higher pressure was applied.

Never had high side connected to low side or to can when trying to refill. I know better than that. And never leaked from the quick connects anywhere. It was actually leaking from the valve body which screws on to the can and I even tightened with a wrench. The gauge set is just cheap and pretty old and hasn't been used in probably 6-7 yrs. Though no plastic anywhere, all metal.

So my choices are go buy a can of 134 and new filler kit for $30 and guess at the correct charge, buy a new/better gauge set and 134 for about $95 and then let those gauges sit around afterwards, or spend prob $120 or so to have a shop do it. (Haven't called around for pricing yet, that's just a guess)

 

I dont know what type of gage set you are using, but you should never have to open the valves under the gages in the manifold to get a pressure reading. Only to add your refrigerant and/or oil charge. There should be a yellow hose on that port in the center and a port at the other end to allow connection to your can.

 

I understand what you are saying..but it doesn't apply to my set. I don't want you to leave thinking I'm a complete idiot...lol. Well...no drawing expert...but lets see.




Might be able to see it better here.
http://i297.photobucket.com/albums/m...Gaugeset-1.jpg

The labels are QC (quick connect), C/O (cutoff valve), gauge and can hose port for 134.
SO, you see if you leave both valves open (I didn't) you can connect the high to the low side. But even with the low side closed, you get high side pressure up to the gauge side of the low side cutoff and to the can if its connected (it wasn't).

Like I said...cheap. Most I've seen have the valves right at the manifold now I think.

 

120 with leak test/evacuation/recharge was what wallimart charged. toss in new stem valves, as they prolly need to be replaced - or it's a good idea to - anyway. but those are cheap.
GG, you know me, i am DIY or die type of guy. but if i see that it may build up fast to the amount they will charge me at a shop - with warranty - i'd let them do it. 120 is not that much, but can here and set there (useless thereafter unless returned) add to 120 very fast.

 

OK, I see what you have... Ive never seen a gage set like that. All I have ever seen or used had 2 gages, one for high and one for low. I understand why you had opened valves now. I am sure you are supposed to open one valve at a time to take the readings separately. Cause I think both of them open at once would not be a good thing.
I have never heard of WalMart doing any type of auto service other than oil changes and tires. I worked part time in the TLE department of a WalMart years ago and trust me you do not want the guys they hire to work on your car. There are a few people that might be able to do the job, but when I worked there they didnt even want us to suggest any maintenance or look at anything. Again that was years ago and things might have changed.

 

Might be some confusion on who used to have a service dept. Remember Kmart used to have Penske auto service? They were pretty much like Firestone or similar. Never saw a Wally World with full service either.

 

super wally does. have seen many here in PacNW and back in TN. can send you pic if you want to. Super Wallies are like Freddies, they have full blown produce, deli, etc, including parts store and service dptmnt. they do tires, minor alignment, balancing, and a/c service.

oh, and they still have it. i drove there few days ago, service dpmnt is still there.

 

here ya go:

Walmart.com: Auto & Tires: Battery and Other Services

 

Guess it depends on the area. Even though ours is a "super"...all they do is oil, tires, batteries, bulbs, and wipers. From the service I got trying to get my oil changed there 2 yrs ago...I wouldn't trust them to check my air pressure.

 

Not trying to start a debate over this, but The WALMART website has a fuel injection service (for $20... cant be much for that price) as general maintenance as well as bulbs, battery service, wiper blades and state inspections where equipment available.

 

Update...
Took it to the shop (4 others came in with A/C issues while I waited)...
Valves were leaking (prob due to me) and charge was down. They changed the valves, vac'd it out, put in 1.5 with leak detector, checked it out and it's working fine. $110 out the door. Gauge set would have cost $70 or more plus cost of Freon and I don't have a vac pump...so pretty good price I'd say.

One question I didn't ask them and prob should have. Receipt says "reclaimed 134a refrigerant" in the standard service description. Just 134a in the parts column. I assume this is probably reclaimed during service and then sent off for filtering, purifying, and such?

 

The reclamation process is done right there in the machine. The machine has a filtering process that it puts all reclaimed refrigerant through so that it can be reused. I dont know why they would put that on their paperwork but it is what it is.