Air Con query

newbiejim

newbiejim

newbiejim

Soldato
Joined
22 Jun 2004
Posts
2,693
Location
South Scotland
Car is Golf MK4 GT TDI, when idling in town air con isnt cold/doesnt cool the car down.... when driving on A roads it is ok, I have tried revving car up when stationary but doesnt make any difference. there is refrigerant in it as I had it checked, any thoughts?
 
Well, the aircon radiator doesn't have a fan to assist it, so when you're in traffic it will be getting pretty hot and this will probably be why you're not getting a good cooling effect.

2 x 120mm deltas and a switch. ;)
 
You sure the main radiator fans are coming on? My aircon got warm in stationary traffic last week and when I checked I found my main fans were not coming on. Given that your car will have a very similar engine bay layout, it would be the first thing i'd check. Fuse is the 3rd one along in the fuse box on top of the battery.

All sorted now and its ice cold again. :)
 
Try running without air-con.
On my Golf (150bhp V5 Auto), without air-con ~27mpg, with it on ~25mpg.
There's a noticeable difference in power by not using the air-con.

These days I only use air-con on long motorway journeys. Any other time I have the windows open.
 
newbiejim said:
hmmm, main radiator fans not coming on but the fuses ok, assuming those fuses are the same as the Leon :confused:
Click to expand...

I'd assume so too, you are looking at the large exposed metal strips, and not the smaller green fuses?

If the main fans are not coming on with the coolant temp above 90ºc then its either the relay or the fuses most likely.
 
Tomsk said:
Try running without air-con.
On my Golf (150bhp V5 Auto), without air-con ~27mpg, with it on ~25mpg.
There's a noticeable difference in power by not using the air-con.

These days I only use air-con on long motorway journeys. Any other time I have the windows open.
Click to expand...

I'd rather be cool than save about 3 pence.
 
There is a common fault with the MK4 fans, they should come on all the time at a low speed with the aircon and speed up if the coolant temp starts to rise. Overtime the low speed resistors burn out new fans are £300 odd from the dealer however there is a very cheap DIY fix on replacing the resistors. Normaly a tell tail sign is the fans pulse to high speed every so often and the fuse pops on top of the battery so it may be a different fault with yours however all the details are here http://uk-mkivs.net/forums/thread/449470.aspx
 
Ive got a mk4 golf and my aircon isn't cold enough either.

Think I might check the fans later in a bit, but basically, when I turn the engine on probably one of the fans will be spinning (as its cold), however when I turn the aircon on, both should start spinning?
 
Tim said:
I'd rather be cool than save about 3 pence.
Click to expand...

I spend aboput half my working day in a greenhouse, so I'm more tolerant of UK summer temperatures. Anyway I'm not bothered by the economy - it's the extra power. :D
 
Tomsk said:
I spend aboput half my working day in a greenhouse, so I'm more tolerant of UK summer temperatures. Anyway I'm not bothered by the economy - it's the extra power. :D
Click to expand...

Get a car that won't miss 15bhp ;)
 
many thanks for all the answers guys, sound slike I have some investigating to do, and err yes it was the green fuses I was looking at :o .. I also went to my mate who has a VW GTI and his fans BOTH come on almost instantaneously at idle..........advice from AN Other advise first to get it fully charged with refrigerant to rule this out first....... dont understand how this would affect the fans coming on though :confused:

the link about the known fault looks very interesting, again many thanks guys, I`ll update with the saga


edit: after reading the link mentioned above it looks VERY like I have that issue :mad:
 
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Tomsk said:
Try running without air-con.
On my Golf (150bhp V5 Auto), without air-con ~27mpg, with it on ~25mpg.
There's a noticeable difference in power by not using the air-con.

These days I only use air-con on long motorway journeys. Any other time I have the windows open.
Click to expand...

MythBusters proved it was more fuel efficient to use the air-con than drive with the windows down :p
 
in addition I have noticed that the air con compressor doesnt start spinning when I switch air con on...............it engages intermittently/randomly(?) whereas my friends seems to be on all the time, when it does engage the main fans still dont come on, I have a real nasty feeling about this one :mad:
 
Tomsk said:
Try running without air-con.
On my Golf (150bhp V5 Auto), without air-con ~27mpg, with it on ~25mpg.
There's a noticeable difference in power by not using the air-con.

These days I only use air-con on long motorway journeys. Any other time I have the windows open.
Click to expand...


i get the same on my fiesta zetec, found my self nearly stalling on every pull off.

it must take up like half my bhp and i aint got much anyway. now its just there to say ive got it :)
 
Seems my fans are doing the same thing, the low speed "constant-on" when the aircon is on is not functioning, and as a result its causing the fuse to blow on the "high-speed" due to it having to pulse on and off too often.

I will be knocking up the resistor-mod at the weekend and we shall see what happens, expect a thread next week :)
 
dbmzk1 said:
MythBusters proved it was more fuel efficient to use the air-con than drive with the windows down :p
Click to expand...

Mythbusters did the test using one make of car, on an oval race track on a day with average wind.

The results would vary from car to car, type/style of driving and drag efficiency of the car.
 
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