Tricky Car air conditioner problem

[stud858]

My car airconditioner started to stop working after driving for around 20 minutes from cold.  It seemed to get really cold and work well for the 20 minutes. when it stopped It needed to be turned off and left off for a few minutes and it would kick back in when turned on again but soon die again after 5 minutes. 
something like blockage or over freezing but in my opinion. over freezing because after time it comes back when freezing melts. That's my thinking from the symptoms I see.

First attempt with one mechanic.
He saw high side was too high (250-300psi)and released some gas and cleaned the condensor situated infront of the radiator. cost 500 baht. didnt help after a long drive.
suggested next step would be to replace expansion valve. cost 3000 baht. 
I got a feeling too much guesswork was in play and wanted to get a 2nd opinion

Next attempt by another mechanic.
saw high side too high aswell and sprayed water across condensor. it lowered the pressure and it was suggested to replace condensor, but after spending more time  with the car diagnosis changed by the mechanic and it was found to be a bad clutch on the compressor. the cost 7000 baht.  I got the feeling that they really didn't know and didn't want to bother and quoted high to cover themselves and later they would mess about and try to find problem by replacing parts and I would later be told different regarding what was wrong and the price. 

Its a Toyota Vios 2003.
Anybody willing to pinpoint which part may be at fault.
I've read on forums someone stated similar problem that after 20 minutes it would stop. Expansion valve was his problem.

Thanks for any help chaps.
Have a brilliant weekend.
 

[stubuzz]

Sounds like the clutch air gap. You should be able to remove a shim. (minor job)

Symtoms: It will work for a short time in hot weather, and work again after it has cooled down. It will work for longer when the weather is cooler.

Google " ac clutch air gap"

However for a more accurate diagnosis, you should have posted the current high and low side pressures and the ambient temperature it was when they were taken.

Edited May 10, 2018 by stubuzz

[Anythingleft?]

Your going round in circles stabbing at things

Drain it, pull a vacuum and fill the stated weight of freon (You have no way of knowing what you have unless you drain it and recharge it)

At least then you know you have at least two items knocked off the list (leaks and correct fill volume) and it gives you something to work from should this not cure it

Also these are two of the cheapest options first off, which in my book is a good place to start.....

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[stud858]

Thanks stubuzz.

I'll read up on the clutch and present ideas to the next mechanic. 

Paying attention to exact details like ambient temp. Evacuating and regasing to exact specs is something they all seem to ignore. I'll try to gather more info. Cheers. 

[stud858]

Thanks anythingleft.

I get your point. 

Once im clearer on the clutch operation after reading on the net I'll inspect what I can myself.

I've read that carefully knocking at the clutch can cause it to then engage and suggest that there is indeed a problem with it. 

I'll ask the next mechanic why he's ignoring a complete regass as a first step. 

[stud858]

I can do an easy check on clutch gap and possibly a real easy fix as the below youtube video suggests.

Could I be this lucky. I'll chase down feeler gauge and cop a feel tomorrow.

 

 

 

[stud858]

On 10/5/2018 at 8:28 PM, stud858 said:

I can do an easy check on clutch gap and possibly a real easy fix as the below youtube video suggests.

Could I be this lucky. I'll chase down feeler gauge and cop a feel tomorrow.

 

 

 

UPDATE .  I'm waiting for a next long drive on a hot day so the air stops working so I can inspect the clutch.  I'd like to see the clutch kick in after knocking it to confirm it's the problem first before asking how much a mechanic will charge to remove a shim. If they go too expensive I'll attempt myself. I'm yet to find a feeler gauge but the gap does look wide to me. 1mm.I've ordered feeler off aliexpress for 2 bucks oz.

Another Update coming soon..

[stud858]

Just now, stud858 said:

On 10/5/2018 at 8:28 PM, stud858 said:

I can do an easy check on clutch gap and possibly a real easy fix as the below youtube video suggests.

Could I be this lucky. I'll chase down feeler gauge and cop a feel tomorrow.

 

 

 

UPDATE .  I'm waiting for a next long drive on a hot day so the air stops working so I can inspect the clutch.  I'd like to see the clutch kick in after knocking it to confirm it's the problem first before asking how much a mechanic will charge to remove a shim. If they go too expensive I'll attempt myself. I'm yet to find a feeler gauge but the gap does look wide to me. 1mm.I've ordered feeler off aliexpress for 2 bucks oz.

Another Update coming soon..

Also. The outer clutch plate is a solid disc with nowhere to tie any thing to it.  I'd have to glue washers to force the plate in a bit if I wanted to do as the above video suggests 

[NanLaew]

13 hours ago, stud858 said:

Also. The outer clutch plate is a solid disc with nowhere to tie any thing to it.  I'd have to glue washers to force the plate in a bit if I wanted to do as the above video suggests 

 

Sounds that like myself you have a degree of DIY savvy about you but the idea of changing my own air conditioner compressor clutch is outwith my own scope of work. After all is said and done, including gluing washers onto hot rotating bits, it may still need refrigerant.

 

Maybe post where you live and a fellow member can refer you to a one-stop, reliable car air-conditioner repair shop that has a good reputation. In my experience, separating a clutch from a compressor may be worth it if the initial removal of the assembly isn't too tedious and time consuming. If it takes him over an hour just to get the combined assembly out, is he going to take another hour to replace the clutch and stick it all back in or slap in a new compressor/clutch combo and save 45 minutes of reassembly time?

[NanLaew]

On 5/10/2018 at 1:26 PM, stud858 said:

Thanks stubuzz.

I'll read up on the clutch and present ideas to the next mechanic. 

Paying attention to exact details like ambient temp. Evacuating and regasing to exact specs is something they all seem to ignore. I'll try to gather more info. Cheers. 

From years of nursing poorly maintained air conditioning systems that I inherited in the Saudi desert, I know the importance of volumes, pressures and temperatures is paramount. But after 2 years, I could turn around maybe 4 or 5 units a night where it took me all day to get one 'just right' when I started fixing them.

 

Although the local guys may look slap dash, chances are after repairing and servicing thousands of similar units in their shop, they have a pretty good idea of what the temperature is inside the shop at 2 PM or at the kerb outside at 10 AM without the need to check a thermometer. A car comes in at noon with a 'warm' air conditioner, he already 'knows' the ambient temperatures in the cab, no need to measure it. Similarly, like I acquired, they have a 'feel' for the gauges that someone who doesn't do this as a trade probably hasn't... like the guy posting a one-off, DIY air conditioner fix video on YouTube. His 10 minute exercise could probably be done in less than half the time by Somchai and achieve exactly the same result.

[Denim]

Just a thought. Have you tried turning the air con control knob on the dashboard  to its lowest setting and the fan on at least mark 2.

 

I had the same problem on my previous car and the air con mechanic told me I had the setting too high and that after an hour of driving the system had frozen.

 

Just by running it at a lower setting cured the problem.

[stud858]

6 minutes ago, Denim said:

Just a thought. Have you tried turning the air con control knob on the dashboard  to its lowest setting and the fan on at least mark 2.

 

I had the same problem on my previous car and the air con mechanic told me I had the setting too high and that after an hour of driving the system had frozen.

 

Just by running it at a lower setting cured the problem

I thought the same but the system eventually shuts down even on low settings. 

Get back to you soon.  It's just a pain that it takes a while for problem to happen.  so I'm waiting for an excuse to go for along drive....along with feeler gauge.... Chat soon.

 

Ps. 

Looks like taking the wheel off and splash guard will gain access to the centre clutch bolt.  Looks not that difficult to remove a shim. Anything deeper would be more of a hassle, but symptoms point to a shim. A few good youtube vids showing how. 

[Anythingleft?]

You mentioned that gas was released, when was it filled last and why?
Had it been running okay since it was last filled?

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[stud858]

3 hours ago, Anythingleft? said:

You mentioned that gas was released, when was it filled last and why?
Had it been running okay since it was last filled?

Sent from my SM-N950F using Tapatalk
 

Big part of the problem is its my ladies recently purchased 2nd hand car so the history is a mystery wrapped in a riddle.  I'll assume gas level is not the problem at this stage.  after releasing small amount of gas problem is the same. Won't be too much hassle or cost to investigate clutch problem first.  If that doesn't help .  I'll pay to have the gas removed,  vaccumed and refilled to correct weight. Some may argue do it the other way round.  But my cognition tells me it's very much, quite possibly,  almost likely a shim removal fix.

It's cool day again today... Waiting for a hotter day so problem pops up quicker so I can investigate more. 

Thanks for sticking with me guys. Chat soon. 

 

 

[VocalNeal]

The clutch thing should be easy. When the AC stops working pull over and see if the compressor is turning.

 

What happens after 20 mins of driving if you go up onto the expressway and get the motor revving a bit.  One of our trucks didn't like it for the first few minutes in traffic and would not run cold. But if one got onto the expressway it would go cold and stay there. Eventually it solved itself.

 

My money is on too much refrigerant.

[stud858]

16 minutes ago, VocalNeal said:

The clutch thing should be easy. When the AC stops working pull over and see if the compressor is turning.

 

What happens after 20 mins of driving if you go up onto the expressway and get the motor revving a bit.  One of our trucks didn't like it for the first few minutes in traffic and would not run cold. But if one got onto the expressway it would go cold and stay there. Eventually it solved itself.

 

My money is on too much refrigerant.

Too much refrigerant is still a possibiliry and it would be that the pressure sensor eventually kicks on stopping the compressor. When I get to test drive again I'll see that the compressor is off. If nudging the clutch gets it to engage I'll continue to check that area.  Also i could check to see if the coil is receiving the 12v. If not off to get it regassed. On a colder day I'm driving for thirty minutes before problem occurs.  hotter day,  maybe 10.. Or less. Once the air blowing is no longer cold. It must be turned off and wait for 5 minutes or so before it works again matching a report from another person about clutch gap problem. 

Sorry to keep you in suspense. I'll be back with more info. 

 

 

 

[stud858]

I went for drive today. Was passing Toyota so thought why not stop in. They are useless as always expected for non warranty work.but I understand they are in it for the big money. Got back in my car.

Kept on driving until problem arose.  Tapping around at clutch didn't make it engage.  Gone was the idea of a simple air gap fix. 

Driving back home I stopped in to a third mechanic to check.  He thought the expansion valve and as this wasn't an outrageous guess and matched with symptoms and forum experiences I decided to go ahead with that. So far so good but I need to drive more to be sure.  Now it still may have been the issue of too much freon, but we'll never know.  Even if it just needed proper regassing knowing there is a new EV is good. 

I'll let you know it's fixed for sure in a few days. 

 

 

 

[stud858]

Also I think,  not sure,  that a small scam was tried on me.

I was shown that my horn relay was no good when I came back to pick up car.

I said leave it.  I'll take care of it. Worst case, he's taken out my good relay and put in a bad one.

You just never know.

I recommend, when work is being done., to stick around and watch like a hawk. 

 

 

 

[stud858]

I went for a long drive today and air con. worked perfectly. 

The expansion valve and or regassing fixed the problem it seems. 

Hope this may help someone where their system stops blowing cold after a certain amount of time and plays up as I described in first post.  

Have a cool day. 

 

 

[VocalNeal]

On 5/15/2018 at 6:16 PM, stud858 said:

Worst case, he's taken out my good relay and put in a bad one.

Or he has switched the bad AC relay for your good horn relay?  Are they the same value/colour?

[stud858]

43 minutes ago, VocalNeal said:

Or he has switched the bad AC relay for your good horn relay?  Are they the same value/colour?

The relay looked scrappy.  The car is second hand when my partner got it. I didn't take notice of the relay before but last I can remember when beeping at a friend it worked.  But even if I was sure, what can I do,  start an argument with a Thai man.  No,  not me. All good.  Ordered another from aliexpress. 60 baht. My partners car is up for sale.  I don't intend to get another one.  Bicycle and public transport for me.  But I recommend if you can,  stick around and observe the mechanic. I've got other scam stories if any one is interested.