Engine off Fans still on! please advise

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
Hi all,

After taking somebody out in the car the other day, drove fairly hard, I parked up and after letting turbo cool for a bit I switched off. - The engine fans were still running and continued for a few minutes.

Ordinarily I would think this was fine, however now, and since, everytime I drive the car and switch off the fans are still running.

I can now only assume there is a problem.:confused: I have lifted the bonnet to check for obvious steaming or oil splatters, low coolent etc but all seems fine - just a bit warm in there and radiator fans running

I have had issues recently with my dashboard temp gauge (water) It will get to 90 then drop, it may keep going up and down in the range below 90 but never goes above 90 - after research I am led to believe that issue is probably the thernmostat, please advise if you feel this is incorrect? - This is an unrelated issue though I'm sure as been like it for about 6months. I am just concerned though as I can't help thinking my temp gauge would not tell me I am overheating now though if its faulty (although like I said it never goes above the 90 mark)!?

My concern now is that because my temp gauge is misleading and the engine fans remain on when I've left the car that I have an overheating issue or may be damaging the engine somehow!? Due for a few long journeys I'm obviously concerned and certainly do not what gasket issues etc

Please advise guys, much appreciated as always;)
 
Last edited:

Dissimulate

Active Member
Jan 12, 2012
68
1
Durham
have you had the water pump replaced at any point?
Maybe try and get a pressure test done to see of thats working properly.
 

Dissimulate

Active Member
Jan 12, 2012
68
1
Durham
i have a list of all possible water gauge/temp reading issues on my home computer. back tomorrow so i'll post a link if you havent already got to the bottom of it.
Has the codes for the little things like small censors which are only a few quid and worth doing before spending more money.
Whats your car/year/milage etc?
 

LEE69

Stage 2 Revo'd
Dec 10, 2004
21,262
74
C\UK\Devon\Torquay
Fans is normal mine does it after ignition is off.

Gauge falling is either a new CTS or a new Stat, both covered extensively on here, search for the link to fix it
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
have you had the water pump replaced at any point?
Maybe try and get a pressure test done to see of thats working properly.

also im guessing the car isnt going into limp mode at all?

Water pump was replaced a few years ago and has the metal impeller. That was after I saw the temp gauge raise above 90 shortly after strating driving

No limp mode, no warning lights - just the fans on after switching off engine

My concern is though that this issue is only after 'caining' it somewhat. Imagine going up Santa Pod strip and then having this issue for days later, thats my situation.

The faulty temp gauge on the dash has been going up and down (always below 90) for over 6 months now so I would guess it was something to do with the radiator fan and/or sensors!? I just dont know at the minute

Really hoping there is somebody who has experienced the same

Cheers for replies though guys, appreciate it
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
Fans is normal mine does it after ignition is off.

Gauge falling is either a new CTS or a new Stat, both covered extensively on here, search for the link to fix it

Appreciate that Lee although this is first time after 4 years where it is after every drive
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
i have a list of all possible water gauge/temp reading issues on my home computer. back tomorrow so i'll post a link if you havent already got to the bottom of it.
Has the codes for the little things like small censors which are only a few quid and worth doing before spending more money.
Whats your car/year/milage etc?

Would appreciate any info, cheers.

03 Cupra 127000 miles (yes that much but well looked after)
 

SubZero

Active Member
Jan 23, 2011
63
1
Midlands
I'm guessing and rather hoping its a sensor of some sort, options:?

Thermostat or thermoswitch?

The fluctuating temperature gauge on your dash is either due to the thermostat (search around on how to test this) or the Coolant Temperature Sensor, both cheap fixes. With regards to your fans staying on with ignition off, I would say the thermoswitch (also called the fan switch and its about £12) as this tells the fans to run at either slow or fast speed depending on the coolant temperature, and as it may be knackered it's activating the fans unnecessarily.
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
The fluctuating temperature gauge on your dash is either due to the thermostat (search around on how to test this) or the Coolant Temperature Sensor, both cheap fixes. With regards to your fans staying on with ignition off, I would say the thermoswitch (also called the fan switch and its about £12) as this tells the fans to run at either slow or fast speed depending on the coolant temperature, and as it may be knackered it's activating the fans unnecessarily.

Thanks for the info guys. Quick update - I noticed that the fans initiate when I turn the key and stay on for 8 mins after engine switched off everytime so there must be a faulty sensor/switch somewhere

I will get to the bottom of this now I hope:), Thankyou for the advice, helping me to narrow down the main cause
 

crud249

Guest
same problem please help

Hi,

I know this thread is old but im having the exact same problem as described with fan run on and coming on as soon as the ignition is switched on. I have tried unplugging every sensor I can find but the fans still come on when the ignitions turned on. Something somewhere is sending a signal to the fcm saying turn fans on and the fan control module is doing just that with the time delay also.

I see freshmode had the exact same problem... if you are still a forum user I would appreciate your help if you managed to sort yours?

Cheers, chris
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
Mate, I have no idea! Still the same. Without removing the front end of the car I'm not sure what to do. I've changed the CTS several times going from the cheapest to the most expensive thinking this must be the issue but sadly not

I've been working away for last year so have just left it - very interested to know what the solution is. It may be a case of just giving it to the stealers and let them diagnose!?
 

crud249

Guest
I've tried everything. The only thing that stops it is pulling the harness plug from the fcm. Ive tried pulling all connectors from climate control and radio and still does it. There must be a switch or sensor somewhere that sends a signal to the fcm saying either engine overheating -turn fans on ... Or air con telling it to turn fans on. Icannot find a proper wiring diagram anywhere either so that makes it more difficult. I defo wouldn't go to stealers they wont have a clue. Only thing left to do is get a wiring diagram and pull or cut certain inputs from the harness that feeds the fcm and try it one by one to islolate the problem

Arrghh!! Doin my head in now.
 

FRESHMODE

FRESHMODE
Oct 9, 2008
249
0
Staffordshire
Well done for what you've tried though! You're on the same line as me - I def think its a circuit issue also. There is a sensor or a switch that is stuck 'on' Or some fault in the wiring to the radiator.

I'm starting to get squealing from the fan every now and then - concerns me that it being doing 'overtime' for too long!

Lets keep trying to highlight this problem, see if anyone has or had this issue

One thing it does provide is good cooling in the hot weather eh!
 

crud249

Guest
Yea ha. As soon as the air cons not needed the harness plug from fcm gets unplugged! Cooling fans still operate from rad switch cos I tried that to make sure. It's gotta be an air con issue. If I sell the car would have to sell it as if it hasn't got air con lol. I'll keep chipping away see if I can sort it. Getting depressed tho ha
 
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