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just recently i notice the fan running on after coming home

the temperature gauge is at normal and dropping but the fan keeps running

what do you chaps think

there is a little cable attached to the bonnet lock...which was disconnected...is that anything to do with it

the top pipe and radiator feel not too hot and i just came home from just a run of about 8 miles..no excessive speed etc

cheers

geof

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1 minute ago, SuperbTWM said:

Probably doing a dpf regen

 

i just disconnected the battery and it stopped but started again

and i noted

the screw down lid on the radiator header tank was loose...

the level seems ok..

so no pressure in the system...

ps

what is dpf regen...??

 

cheers

geof

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1 minute ago, SuperbTWM said:

DPF is the particulate filter, but just noticed your car is a 2008 so not sure if it has one. Sounds like you may have another issue.

 

 

yes if i remember i checked this on the spec label in front of the owners handbook

i dont think i have one

the cooling fan...how is this related to an exhaust filter etc

i thought it ran if the temperature of the engine got high... like in traffic

my radiator is cool but the lid on the pressure header was loose...so raising the temperature of the fluid or even boiling off...the level looks ok

but i will top it up..

there must be a sensor for the fan somewhere with some logic to the electrics

the in car temp gauge was at 90 but is lower now..

cheers

geof

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The temp will nearly always show 90*oC even if a little higher, but there is no issue with the fan running on as long as it stops after a few minutes, 

the Coolant might be 90*oC ish but then it trys to stay like that, the oil may be higher and the coolant cools the oil, and the fan keeps the coolant cool etc etc 

 

As to topping up coolant, if between MIN & MAX that is fine, there is no FILL TO THE LEVEL line, 

so it at MAX and then settles at between MIN & MAX after it self bleeds that is fine.

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15 minutes ago, Awayoffski said:

The temp will nearly always show 90*oC even if a little higher, but there is no issue with the fan running on as long as it stops after a few minutes, 

the Coolant might be 90*oC ish but then it trys to stay like that, the oil may be higher and the coolant cools the oil, and the fan keeps the coolant cool etc etc 

 

As to topping up coolant, if between MIN & MAX that is fine, there is no FILL TO THE LEVEL line, 

so it at MAX and then settles at between MIN & MAX after it self bleeds that is fine.

 

cheers

i disconnected the battery so the fan hasnt been running since i posted originally...but on reconnection it still wants to run

i think its must be the oil which is hot then??...the oil level is ok..

the lid on the pressure header...now its tight on and the coolant level is between min and max...good

think i should give it a run...need some diesel anyway..

or i could just leave it overnight with the battery disconnected...and see if it all has cooled overnight

what do you think

cheers

geof

Edited by mrcrow
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33 minutes ago, mrcrow said:

 

yes if i remember i checked this on the spec label in front of the owners handbook

i dont think i have one

the cooling fan...how is this related to an exhaust filter etc

i thought it ran if the temperature of the engine got high... like in traffic

my radiator is cool but the lid on the pressure header was loose...so raising the temperature of the fluid or even boiling off...the level looks ok

but i will top it up..

there must be a sensor for the fan somewhere with some logic to the electrics

the in car temp gauge was at 90 but is lower now..

cheers

geof

As mentioned the temperature gauge does have a frig factor in the software so it will read 90 even if the car gets hot enough to kick the fan in but I don't think it should stay on when you turn the ignition off if this was the case unless the car was dangerously hot. Plus a diesel engine runs a lot cooler than a petrol one, I have never witnessed my fans running unless it has been DPF or air con related even when its been stood idling for a decent period.

 

You could also have a faulty temperature sensor as one part of the sensor feeds the dash reading and the other one feds the ECU which may control the fan. Checking it with VCDS or a scan tool to read live data would prove that side of things.

 

How many fans does the car have?

 

Have you plugged the bonnet catch back in?

Edited by SuperbTWM
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19 minutes ago, SuperbTWM said:

As mentioned the temperature gauge does have a frig factor in the software so it will read 90 even if the car gets hot enough to kick the fan in but I don't think it should stay on when you turn the ignition off if this was the case unless the car was dangerously hot. Plus a diesel engine runs a lot cooler than a petrol one, I have never witnessed my fans running unless it has been DPF or air con related even when its been stood idling for a decent period.

 

You could also have a faulty temperature sensor as one part of the sensor feeds the dash reading and the other one feds the ECU which may control the fan. Checking it with VCDS or a scan tool to read live data would prove that side of things.

 

How many fans does the car have?

 

Have you plugged the bonnet catch back in?

 

:D

yes...what does that cable do...tell me if the bonnet is open??

never noticed before

only one fan...

i will have another look then off to bed...more tomorrow

cheers

geof

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There is usually a separate thermal switch on the radiator or elsewhere on the cooling water system that switches the fan and either slow or fast speeds. You might not get the wipers to work if the bonnet micro switch cable is disconnected as well as maybe something else, I've forgotten!

 

Edit:- I suppose if when you next go to this car with the coolant cold, and you reconnect the battery, if the fan starts to run then you might consider that the fan control module might be faulty?

Edited by rum4mo
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11 hours ago, rum4mo said:

There is usually a separate thermal switch on the radiator or elsewhere on the cooling water system that switches the fan and either slow or fast speeds. You might not get the wipers to work if the bonnet micro switch cable is disconnected as well as maybe something else, I've forgotten!

 

Edit:- I suppose if when you next go to this car with the coolant cold, and you reconnect the battery, if the fan starts to run then you might consider that the fan control module might be faulty?

Yes..did that just now 

cold engine, oil and water ok

bonnet switch connected, wiper have been working anyway.

fan still runs, will get a torch later and look for a sensor or fan control etc

not too easy to see what's going on down there.

may be a diagnostic trip to the Skoda dealer..get the AC done as well 

cant be DIY all the time 

I am doing the bathroom revamp so my mind is a bit bogged down with all those waste pipe sizes

cheers

Geof 

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had a look at the drivers manual...and checked that the fuse is ok...obviously is

but now i can remove the fuse if i think i dont want this fan running overnight...and so not having to disconnect the battery to do that

i dont like having the car not connected...a fear thing left over i think from my 2001 golf 1.6S...electronics/electronics

a puzzlement...resetting etc

the skoda is good...the only thing not maintained is the computer details although it takes a guess at how many miles left in the tank...i think its favourite number is 50 miles..:D

so

we has as you may have seen on the news a great downpour each day for about three days..coverack is in this area

well my bottom road entering into my estate was deeply flooded and i reckon some tsunami or other may have entered the lower reaches of the engine compartment where i understand the lower connection to the radiator..and i suspect the device to switch the fan on and off attached perhaps

may have gotten a little dip in the rainwater

equally yesterday on my way home from some shopping i drove through a lengthy cloudburst...ditto..more water on the roads

i need to locate any component which switches the fan on and then off ...a sensor...and do some remedial work...so far i am not clear on this

if anyone has accessed the lower radiator area where i think this object is...and found it no problem...etc..i would be grateful for the advice and source of any component.

the air con is still on the table for a service but if i go into the dealer with this fan thing i may be coerced to having it done as well...and i am getting very pleased about how easy? the skoda is to sort out relatively simple maintenance

finally...would the chaps there advise on a tool which i could use to do diagnostice...i see it throws up some valid pointers as to where and what some maladies are caused by

cheers

geof

ps its sunny hayle again..:)

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Radiator thermoswitch is a few inches above where the bottom hose connects to the radiator. Should be a waterproof connector but worth checking for ingress.

Fan control module is just outboard of there on a bracket bolted to the nearside chassis leg.

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27 minutes ago, Wino said:

Radiator thermoswitch is a few inches above where the bottom hose connects to the radiator. Should be a waterproof connector but worth checking for ingress.

Fan control module is just outboard of there on a bracket bolted to the nearside chassis leg.

thanks...i thought there might be a hose nearby

the problem for me is i am looking down on it....is it serviceable from below...there are loads of cable harnesses..the windy hose type in the way...

mine is a fabia 2 1.4 diesel...does the grill come off easily

if you have done this and can give me a starter for 10 i would be happy

i spent the first 5 years of my working life in the bilges and sumps of ships engines and what not

so i do appreciate dirt and difficult access but like to avoid it if possible...once one has done it..it is easier to explain

cheers...and thanks

geof

Edited by mrcrow
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I think "fan run on" is a fairly common thing these days. I've noticed it on a few cars I've had in recent years.

 

Provided water and oil levels are all OK and it switches off after a few minutes, I wouldn't worry about it.

 

I think it's down to manufacturers optimising (minimising) coolant volumes to assist with quick warm up and fuel economy.

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19 minutes ago, Wino said:

Access to both of these is better from below. 

 

thanks...i just saw on the skoda manual the whole of the front of the car hinged out on a chair

it was a mark 1

 

will do a photo shoot on the job if i can do it

cheers...and thanks

geof

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9 minutes ago, BoxerBoy said:

I think "fan run on" is a fairly common thing these days. I've noticed it on a few cars I've had in recent years.

 

Provided water and oil levels are all OK and it switches off after a few minutes, I wouldn't worry about it.

 

I think it's down to manufacturers optimising (minimising) coolant volumes to assist with quick warm up and fuel economy.

 

this fan though is in the london marathon...still running

will post results when i find the culprit

yes running on is normal...especially after a bit of heavy traffic on a hot day

i thought it would stop

went out really late and all systems cold...still running

i disconnected the battery and bid it a good night...next day reconnect...brrrrrrrrrrrrrrrrrrrrrrrrrrr

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Sounds quite odd to me. I know they do run a bit after turning off but they should stop again. Sounds like its getting a signal to cool all the time rather then when hot!

Coolant temp sensor/switch fault? I remember having a fan NOT coming on once and the mechanic "Shorting" across the terminals to create circuit which turned the fan on so perhaps that wet weather shorted the fan, creating the circuit to stay on. Only a thought!

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You are lucky, if the fault is still present it should be dead easy to find the fault.

 

I would start by determining if the fan is controlled via a separate switch on the radiator or via the coolant temp sensor. Then test that bit first.

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My 1.6 tdi mk6 golf has had the same symptoms since i bought it. I was told it was fine. It had went over 90 to about 100 mark on the gauge. Replaced water pump and timing belt. It was fine for about 500 miles until now. Fans usually on even after light driving but don't seem to come on when they need to? No fault codes, no loss of coolant, no drop of mpg etc

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Is the fan switched through a relay? Could have welded it's contacts together if it has. Just a thought. 

Edited by Wonky
Typo
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25 minutes ago, Wonky said:

Is the fan switched through a relay? Could have welded it's contacts together if it has. Just a thought. 

Two actually. One for low speed operation, another for full speed. Both reside in the fan control module.

If the problem isn't water ingress shorting stuff, welded contacts is probably the most likely explanation.

 

 

20160514_110547.jpg

 

That's the PAS pump/reservoir on the  left of the fan module in the picture, and an extreme close-up of the radiator drain tap on the right.

Edited by Wino
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21 hours ago, mrgf said:

Sounds quite odd to me. I know they do run a bit after turning off but they should stop again. Sounds like its getting a signal to cool all the time rather then when hot!

Coolant temp sensor/switch fault? I remember having a fan NOT coming on once and the mechanic "Shorting" across the terminals to create circuit which turned the fan on so perhaps that wet weather shorted the fan, creating the circuit to stay on. Only a thought!

 

my thoughts too...

thanks any input is really helpful..and i need it..and the plot is getting clearer

the events leading up to this situation was flooded roads and torrential rain

so now i suspect water ingress...it doesnt look like anything is drying out...will give it a few more days

mainly..

i appreciate the pictures and detailed analysis....what could be my next bridge to far is getting access to the possible components... which is normal but without access to a ramp to take off the giant plastic under engine cowling...which is a great feature..

i wont be able to check the items or replace them, which for me is better than an oldie which might go again....

costs of spares is not a problem for me and the skoda spares come from a good source...vag or vw

what i am now considering in the medium term is to let the skoda dealer have it to sort out the analysis of what is wrong and pay for spares and time to fix it....unfortunately as the labour i offer is first class and free...:D

just confirm anyone who took pictures and fixed any of the items...had access to a ramp or are professional mechanics

cheers

geof

 

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18 hours ago, SuperbTWM said:

You are lucky, if the fault is still present it should be dead easy to find the fault.

 

I would start by determining if the fan is controlled via a separate switch on the radiator or via the coolant temp sensor. Then test that bit first.

 yes thanks...i have looked but my viewpoint is above the radiator with a torch...so access is tricky...battery disconnected of course...with a hand...and as i can see and have been advised...the work is from below...but for reasons above outwith my situation

no ramp....

i am still doing the overnight disconnecting the battery and during the day parking up to 3 hours doesnt drain the battery...its a new one and a big one..77Ah...just changed

i am really thankful that the radio/cd just remembers all i want it to and all i have to do is reset the clock...i have a second battery operated one on the passengers side...sits on the dash

the computer is still telling me wonky info how many miles to empty....but i am filling up tomorrow from 1/4 full so i dont have to worry about that

hope to resolve this within a week...a tank lasts around a month local driving

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