Need advice ASAP please (faulty rad fans)

[RabReith89]

Hi guys I have this major problem which my 225 leon cupra r 58000miles.

When I was sitting at the lights I heard a beep and noticed that my water temp hit 120 so pulled over right away to let the car cool down, had a look over the engine bay checked coolant, leaks, also scanned for faults! After letting the car cool down I started it back up and left it to idle the temp slowly went back up to 105 on the liquid gauge I then turned the engine off, there was no bubbling or noises. Also notice the fans never went on at all!! I done a little test by turning the engine on and switching on ac there was also no fans but only a noise when I put it on like it was trying to :s

I let the car cool down for a few hours while I went to the gym, when
I got back I looked for leaks underneath there was none. I drove the car home
Which is 15miles or so just taking the easy going about 40-50mph few stop at lights, when parking up the temp then rises up to 100 I waited for fans but nothing

I am scared just in case there has been any damage to the head ect!! Plz guys any ideas would be very helpful. Have my mot and tax tomorrow this is the last thing I need

Thanks Rab

 

[mty12345]

re fans

hi mate, if you do a search on here for a thread called " Overheating (Update Post 35, please help!)" i explained to a guy with similar issues how to check your fans, hopefully that may be some help to you

 

[RabReith89]

Yea found that mate thanks, sounds like we are having exact same problems.

 

[RabReith89]

Bump

 

[RabReith89]

Can anyone plz tell me where I could find the fan thermoswitch?? Have read everything I can but not sure where it is on the rad?

Thank

 

[oldman]

read a very long thread on this and search for nime box
known commonish fault

slow speed fan issue is what you need to look for

 

[RabReith89]

Was gonna test the fan thermoswitch mate, they say its on the rad triangle shape? also iv been reading for hours but can't find what am looking for!

 

[jamie1]

checkthe fuses on top of the battery mate, my guess is either blown fuse or poor connection on the fuses..

 

[RabReith89]

Done that last night buddy also checked fuse 25 inside the car. Just drove my car bout 15mile into town booted it few times, held a steady 88-90 so I assume it's not a waterpump issue?


The rad when I stoped was hot but not boiling, is this a good thing since if it was cold that would cause the fans to think they warnt needed?

Thanks for any help

 

[jamie1]

does the bottom hose get hot?

 

[RabReith89]

If u mean the hose that gose from that rad to the block yea it is?

If someone could just tell me where the rad switch or sensor is I can rule it out to see if they work with 12v

 

[oldman]

thermostat is built into the radiators themselves

you need nime box to fix the slow speed issue i reckon you are hitting
many threads on this. search for nime and its the one about 6million pages long

 

[oldman]

read this thread:
http://www.seatcupra.net/forums/showthread.php?t=137571&highlight=slow+speed

 

[mty12345]

fan switch BAM

on the BAM engine your fan switch should be on the front bottom left of radiator as you look from front of car

 

[wayne lcr]

thermo is not built into the rad at all its under the manni 2 10mm bolts took mine out other day.ive just had this yest and it was the 2nd water pump the silver can on the back of the rad was sticking tapped with hammer gentle took the electric plug of cleaned that and run the heater on full wack and it kicked the pump back into life.when you put you ign on make suren it buzzers mine had stoped. and i got the red light on the temp screaming at me as soon as the pump started working again the temp stop0ed doing it and the car is fine now.

 

[RabReith89]

UPDATE

while looking over my cars fuses agen before mot I came across the 40a fuse had blown in half?? So called stealers. Once fitted the fans then kicked in at 98, seems it's the fast speed tho. Fans still don't turn on when ac is on? Been driving round town and seems fine fans kicking in when it hit 100 for 10secs. Any ideas on the small fan problem guys?

Oh btw my car passed the mot cheered me up

Thanks Rab

 

[Muttley]

Fans should both come on together, slow when the a/c is on and also when the radiator temperature gets up to 95°C or so.

The thermoswitch is mounted in the radiator above the bottom hose connection.

wayne-lcr, the thermoswitch is not the same as the thermostat. One is electrical, the other is not.

Slow speed is done by having a resistor in series with each fan motor. This resistor is built into the fan itself, not practical to get at it to replace. Some cars (LCRS's seem particularly vulnerable) have a tendency to blow this resistor. When this happens the water temperature rises until it hits the full-speed fan level, somewhere about 100°C. Full speed fans are very loud.

If you only have full speed fans, then your slow speed resistors have probably burned out. Your options are
1-replace the fans
2-wire in new resistors
or
3-get a Nime box.

If you do nothing then the fuse will blow again and eventually the fan motors will burn out.

 

[RabReith89]

Thanks mate. So there's no chance that there's a lose wire ect that could be cause this, if I test the fans can I test the slow speed and if it works dose that mean the resistor is ok?

If I replaced the fan due to slow resistor blowing do I have to replace both? How much are they going for with fitting??

Thanks alot Rab

 

[RabReith89]

Bump anyone plz :s

Been reading old threads for hours.

Seems like nearly every r on the road has or will have the problem!!

 

[Muttley]

Take the plug off the thermoswitch. Switch on ignition. There are three connectors in the plug. They are power, slow speed fans, full speed fans. Bridge out each pair, one after the other. One pair will do nothing, one pair should start the fans spinning fast and the third pair should start them slow.

If you can get both slow and full speed fans this way, then either the thermoswitch is faulty or possibly the fan control module.