150 tdi air con crap

[V9FOS]

hi everyone,
i have recently purchased a mk 4 golt 02 gt tdi 150,we already have a mk 4 150 gti petrol also.i've noticed that the diesel golf has very poor air con on tick over compared to the petrol model.first thing i did was have it re-gased but this has proved usless.the only other thing i have noticed is that my petrol golf air con compressor is constantly working wit both fan intermitantly cutting in and out where my diesel one the compressor cuts in then out and no fans run at all untill the engine starts to get warm and then both radiator fans cut in.to cool the engine.the car seems fine when the car is moving.can anyone throw any light on this problem 4 me?????

[robert310383]

are we talking cockpit fans or external radiator fans?

[V9FOS]

Hi, i'm talking about the fans under the bonnet(not the internal fans)
regards scott

[robert310383]

have a look at this https://www.vwaudiforum.co.uk/forum/s...ad.php?t=43244

[V9FOS]

Sorry guys i've just realised that there are no engine fans cutting in at all. The interior fans run but not cold with air con on.checked all fuses but all seem ok.does anyone know which fuse is radiator fan one,or what the poss problem is,summer is on top of us and really dont want the car to overheat.

[Crasher]

Sounds like typical 150PD fan failure. If the fans don’t come on when you turn the A/C on and then only work when the engine gets hot, they are faulty. Almost every PD 150 I get in has faulty fans (except the Bora I had in today), they are specific to the PD150, V5 and V6/R32 and I change lots. The fans cost £300 odd and take about and hour and a half to fit. Pop the battery cover off and the fuse for the fans is one of the strip fuses on your left (the cars right) and has a thick red wire going to it and another fuse with a very thick red/black wire. If either has blown replacing it will restore the high temp running for a while but new fans will have to be fitted. A chap last week with a V6 4 Motion nearly lost his engine because of this.

[V9FOS]

Thanks crasher for that.well i've checked all the fuses under the bonnet and by the battery and all seem ok.i had the car running for ticking over for ages today and the temp never goes over 90 and no fans cut in to keep it cool so how come it does not overheat???? is there any easy way of checking if either of the fans work and what sort of job is it to get the fans off the car to replace myself.i do have a fair amount of knowladge about cars but was wondering which way they come out and what do i have to remove first ect.

[Crasher]

It’s a diesel; you would have to run it at about 3000 rpm for half an hour to get it hot enough to make the fans come on. The dash gauge reads 90 when it is really 73 and still reads 90 when it is 114-stupid! To check the fans you have to remove the plug to the fan switch down below the battery and jump across from the red to the red/white and then the red to the red/black. One will run ignition on or off, the other ignition on only, I can’t remember which way around, I would look it up but tea break is over now and I have to get back to the Ibiza Cupra R consul bushes I am fitting to a Fabia VRS.

[robert310383]

I have driven mine around for 15 months now and the fans never come on, yet it never over heats. shouldnt it have blown up by now?

[Crasher]

Diesels never get hot enough when driving around, road draught through the radiator is sufficient. When I service a TDI, I insist on checking the fans work (no one else does) and that means holding the revs at 3K for about twenty minutes and eventually they may come on. Due to their failure being so common and the gauge being so inaccurate, I always do this whilst watching the coolant temp sender in Measuring Blocks 08 and if the fans have not come on by around 103 degrees, I know something is wrong. The two most common causes of poor air con I see are rad fan failure and compressor failure, especially the latest clutchless compressors which are utter crap.