Mysterious overheating/fan issue

[Error404]

the headgasket going still doesn't explain why your 2nd stage fan doesn't work.

AFAIK the 1st stage should only come on when the AC is switched on or with the after-run pump activated (you can test these functions).

The second stage will kick in at 90deg or thereabouts, the 3rd stage later probably around where yours does, a couple marks above 90deg, at a guess around 105-110 degrees.
The fan normally only runs for around 10 seconds, just enough to satisfy the rad thermo switch, then it will switch off again until the temp rises and so on.

In reality you should rarely see the 3rd stage running in normal driving as the 2nd stage takes care of the bulk of the cooling work - obviously the 3rd stage kicks in when its not enough.

There is a possibility all this hot running has contributed to the HG starting to go. The HG doesn't have anything to do with the 2nd stage fan not kicking in

HTH

[PeterS]

on the 7a equipped Coupe Quattros and 90s, the fan loom & connector are a know area of trouble...some of the installations have no loom strain relief, so a combination of mechanical, thermal and electrical stress causes failure of the fan connector and sometimes the the internal fan connectors.

I would first electrically check the connection at the back of the fan...

[Mikes2]

There is a simple way to test if the fan circuit is actually working.

Disconnect the rad thermoswitch connector. Turn on ignition. Use a short wire to bridge the wiring in the connector. First bridge pin 1/2 and then 1/3 and finally 2/3.

The fan should run each time you bridge the wires.

[Pirvu Eugen]

Iff first and third speed are working...then is not the fan.
is the termoswitch from the radiator, the wiring between the switch and relay or the second speed relay himself.
Hope this helps!

[lagz33]

From what ive gathered now only third speed is working, I just drove home after doing the head gasket test and spilling out loads of coolant it got up to the first dot on the temp gauge, and the bloody after run pump kicked in for a little bit after turning engine off.

Either way now, the way I see it the engine is knackered, will drive 50 mile a day round trip now mon-fri till I find/get money together for a banger so I can put her away to get her fixed up and upgraded like I intended a long time ago.

Not a happy bunny as i'm broke and now so is my car

If anyone fancies doing the head for me at "nice" rates PM me otherwise the soonest I can get it done is on the 24th onwards.

[rynaqui]

Try not to stress it too much, hope you get it sorted soon

[Pirvu Eugen]

Iff only the third is working...then is verry possible that the fan is dead or the plug at the fan is toasted.
The first speed is coming throw 1 resistor into the second speed pin at the fan.
the second speed is directly at the same pin at the fan wich has incorporated another resitor.
The third speed is fed into an different pin at the fan and so...the only fan speed you have is the third.
Iff this is the case....i am pretty sure 1 off the resistor wires inside the fan are toasted.
Offf...hope you succeed to fix this soon...dont overheat the engine though....make tests like above with bridges at the temp switch.
Goodluck!

[lagz33]

Phew, managed to grab myself what I think was a bit of a bargain (£275) to get me to work whilst the S2 gets a full overhaul and upgrade.
Bought a T reg Seat Cordoba SX 2.0 16v with 118k in very nice condition and new clutch. Quite nippy too

Will sort the S2's fan,gasket and lots of upgrades in next few months

Thanks for your help as always guys!

[sailaz]

There is a simple way to test if the fan circuit is actually working.

Disconnect the rad thermoswitch connector. Turn on ignition. Use a short wire to bridge the wiring in the connector. First bridge pin 1/2 and then 1/3 and finally 2/3.

The fan should run each time you bridge the wires.

Could anybody give advice regarding constantly running 2nd speed, it's starting when I switch ignition on when engine is cold, if I disconnect thermoswitch connector it's stays running, if I take out bottom 214 relay, which is for 1st speed, then fan stops



I think it is running on second speed, because if I bridge pins 2/3 it's stays running on the same speed, if I bridge 1/3 it's kicking in to 3rd speed. To bridge pins 1/2 doesn't make any sense and i even didn't try ...
So, at the end I'm completely confused and a 'bit angry'

[220bhp]

If the head gasket is leaking from a cylinder to a waterway it will pressurise the system and push water out of the header tank.
When you take the head of you need to check for corrosion in the waterways. this can happen when the wrong antifreeze has been used during the cars life.
The other thing is to have it crack tested. I would also have the head checked to see that it is flat. If not, then have it skimmed.
Victor Rienze metal head gasket , new head bolts, , water pump, and the short piece of rubber water hose on the side of the block, and your away. I would also think about doing the cam belt at the same time
You don't have to do all these items, but if you don't, Then they will come back to haunt you.
Doing a head gasket is not as scary as it looks. Leave the manifolds on, and gets some help to lift it of. put it back the same way. much easier than trying to undo all the exhaust nut on the car. That really can be a nightmare. when its of you have a better chance to sort the radiator fan, more room.
Good luck

[sailaz]

I like your sarcastic advice , honestly

[sailaz]

problem was A/C high pressure switch for electric fan 8A0959482AB, No.25.
What I don't understand why it became active after freon was released from system it says 'high' not 'low' pressure switch

second picture is not very proper but it shows proper part numbers for RS2.

[Henkjan]

Could anybody give advice regarding constantly running 2nd speed, it's starting when I switch ignition on when engine is cold, if I disconnect thermoswitch connector it's stays running, if I take out bottom 214 relay, which is for 1st speed, then fan stops

I had a similar problem, i my case the fan stopped when I took out the fan afterrun relay (yellow arrow)

problem was A/C high pressure switch for electric fan 8A0959482AB, No.25. What I don't understand why it became active after freon was released from system it says 'high' not 'low' pressure switch

that's odd... I have low pressure in freon system as well and think of ditching the whole airco, would be if this caused al sorts of new problems

[sailaz]

I had a similar problem, i my case the fan stopped when I took out the fan afterrun relay (yellow arrow)

there is no that relay in my RS2 (pic attached)

that's odd... I have low pressure in freon system as well and think of ditching the whole airco, would be if this caused al sorts of new problems

what you mean by saying 'low pressure in freon system' ? you get that kind fault code or what ? what sort of all new problems ? or just you know that freon is leaking ?

[Henkjan]

yep aircon is not cooling, fault code says low pressure in coolant.

with "new problems" I mean the kind you report where the running fan is (possibly) caused by having no freon in yr airco, the kind of problems you don't expect to happen