Air Con Problem

[wackyjim]

With all this good weather recently I have had to make full use of the air con and although it is working it hasn't been what you might call ice cold so took the car ( 95 LS400 Mk3) into a specialist in Dundee this morning for a check up and he gave the system a service and recharge including oil etc for £50 and although it's better (12 c at the vents) it's not brilliant. The guy reckons that the Lexus came with a front cooling electric fan for the condenser which isn't on mine and is the reason why I can't get decent cooling...Looking at the radiator there is no visible sign of a fan ever being fitted so can anyone tell me if there should be one there and if so where can I get one?

[Rupert Dubreaux]

Hi Jim ,the Mk3 UK models didn't come with a fan fitted .It is not hot enough here to warrant one it seems ,on the Mk 2 you do get a cooling fan, seems like another cost cutting measure that was coming in for later models .

[wackyjim]

Thanks Rupert...The air con guy said that he could fit one quite easily and actually recommended the electric fan fitted to a Vauxhall Astra...believe it or not!! Anyway I think I'll wait and see if the really hot weather returns before doing anything like that

[Ruud]

I've got a '96 and my A/C is plenty cold in this hot weather. 3 degrees at the vent. I don't think the lack of a fan is the issue here.

[wackyjim]

Rudy...I had a Mk4 before the Mk3 and the air con was great on that car and I can't remember it having an auxiliary fan for the air con either? What else could it be??

[Ruud]

I am not sure. I take it your A/C guy has had the system vacuum for a while?

[wackyjim]

Yep...removed all the remaining gas then recharged with 680g of L134 gas including the correct oil, the whole process took about 30 minutes

[Ruud]

That might be the issue right there. From memory it takes close to 1000g

[wackyjim]

He told me it was 810g for cars with front and rear air con and 700g with front only ,he didn't want to put the full 700g in due to age of the car which is why he put in 680g

[Ruud]

I have checked several websites from A/C specialists with a R134a capacity list and they all are around 33 to 37 oz which roughly translates to 935g up to 1000g.

Do a search on google yourself and see what you find

[wackyjim]

Thanks Rudy...I'm going to phone the garage tomorrow and tell them about this . As you say this could be the problem and if there is only 2/3rds of the recommended gas in the system then no wonder it's not performing properly!!

[Titch LS]

Jim, It should take 750g for a full charge. Just had mine done on my mk4. It's now ice cold. Beautiful.

[wackyjim]

Thanks Brian :)

[Ruud]

I think the mkIII takes slightly more though - not sure why

[wackyjim]

Garage recharged the car again this morning and put 850g of gas into the system. The temp at the vents is now showing 9c which although not perfect is a big improvement, he checked the pollen filter and it was pretty filthy so he air blasted it and ordered a new one which I will get fitted tomorrow he is also going to clean the vaporiser and will set up a temporary fan to blow over the condenser just to see what difference that makes. The garage have been great and only to keen to help get things right for me.

[ambermarine]

Just a couple of points for other members worrying about how much to add when the A/C does not freeze your finger tips.The early Mark 1&2 had condensor fans which were dropped on later models mainly because as one member as rightly pointed out it never gets desert hot in the UK for any length of time.

Also the lowest temprature that comes out of the vents was raised because the cold setting on the early models was unpleasant ,remember the A/C is supposed to be climate control orientated not fridge driven.

By the time they got to the Mark 4 the A/C had been refined to just about the right ambient temprature for the UK and is not supposed to freeze your finger tips.

The correct amount of R134a is quite easy to calculate;

On the top of the receiver/drier ,the canister that sits forward of the condensor behind the front grill is a small circular window.

When the car is started with the A/C on immediatly the window should foam with air bubbles and within ten seconds go clear the reverse sequence should also occur when the engine is switched off or the A/C is turned off.If the foaming is continuos there is not enough gas in the system and if it keeps foaming after more and more gas is added beyond the reccomended amount there is probably a leak in the system.

[wackyjim]

Ambermarine.....The garage told me that the target temp at the vents should be between 5c and 6c, I have just checked the the little green window on the canister and can't see any sign of bubbles so I don't know if that is significant or not??

[ambermarine]

If its clear when the A/C is on it is functioning correctly.It will be clear when the A/C is turned off after the sequences I described earlier.It is the easiest way to check if there is enough gas in the system.

[SHELLDRAKE]

Hi Boys : I have just been out and checked the A/C window it turned green and stayed that colour until I turned the engine off, but it was still showing green when I closed the bonnet ( no signs of bubbles at all) so what is the problem then gents.

[SHELLDRAKE]

Well tried the A/C again today same results, still showing green no bubbles, looks like a service job is on the cards but not at Lexus.

[ambermarine]

Norman

When you say green which glass are you looking at ,is it the one on the top of the canister in front of the Radiator just above the front bumper.

[wackyjim]

^ That's the one I'm looking at which appears green when the air-con is working

[ambermarine]

Well there is something not right, the glass should be clear when the engine is off and you should be able to see the shiny metal in the chamber,when you start the engine that chamber fills with foaming air bubbles and after 10-15 seconds clears and you will see the shiny chamber metal again .When you switch off the cavity fills up with foam air bubbles and then clears in a about 30 seconds.

Give the glass a good cleaning it could be covered in road gunge

[wackyjim]

Will give it a clean and have another look tomorrow

[SHELLDRAKE]

This is what the A/C looks like when it is turned on can anyone say what is causing it.