Not a Fan!

[bigbluec 0]

Hi guys yet another niggle on the C !

Have noticed in the last few days that the fan will cut in and out repetitvely after the engine is turned off.

And although i know that it does run after the engine is turned off (when Hot), lately its been doing it even when i turn off and the water temp is only 70 - 80 deg and the oil temp is normal. so surely its got to be a thermostat problem or a fan relay?

Any help would be appreciated... Cheers Guys

[dr_mat 0]

The weather has been very hot... I would say that as the lower fan speed should cut in at 84 degrees it's quite possible your gauge is inaccurate enough for that to be the real temps under the bonnet.

Anyway, if you're really worried about it, it might be worth swapping the fan thermo switch.

[Henny 0]

Dunno about the other versions, but on a G60 there is a thermo switch above the inlet manifold which controls the fan run on. If the inlet/exhaust manifold temps are high (due to the weather and having been sat in traffic etc) then this sensor can keep cutting the fan in and out to make sure you don't overheat the petrol in the lines and not be able to start it again...

 

This is all normal and shouldn't be considered as a fault unless it is doing it more than about 30 minutes after being turned off... 8)

[Robbo149 0]

I was just about to post on this exact problem! wierd! I've noticed my fan coming on when the engine is well cooled down, sometimes 2-3 hours later! It seems to work normally when driving, I'm not getting any problems with overheating.

 

Where is the fan thermo switch on a VR6?

 

Cheers,

Robbo

[dr_mat 0]

It certainly shouldn't come on for more than a few minutes after the engine has been turned off.

Definitely not - there's a timer on the circuit, no matter how hot it remains..

[Robbo149 0]

It only stays on for a couple of minutes, but it's coming on when the engine's had plenty of time to cool down (sometimes a couple of hours later!)

 

Robbo

[dr_mat 0]

You mean when you re-start the car or it just spontaneously come on for no apparent reason??

[kongo127 0]

I was just about to post on this exact problem! wierd! I've noticed my fan coming on when the engine is well cooled down, sometimes 2-3 hours later! It seems to work normally when driving, I'm not getting any problems with overheating.

 

Where is the fan thermo switch on a VR6?

 

Cheers,

Robbo

2 - 3 hours later??? :shock:

My G60 starts the fan when i turn off the car most of the times.

Once i stayed to hear the fan cutting off and it took about 15 minutes.

There was one time that i heard the fan running after i switched off the car 45 minutes :shock: ( but intermittent, not running consecutively) although it was a very hot day and i was driving a little bit hard...

I was worried but it never happened again...

[Robbo149 0]

Yeah Mat, it seems to come on spontaneously, it doesn't stay on for 2-3 hours Kongo! I mean't that I've heard it come on 2-3 hours after I've switched the engine off, then running for a few minutes before switching off again. Could there be a sensor/switch fault somewhere?

 

Cheers,

 

Robbo

[kongo127 0]

Is the water hot for real? :?:

Have you ever saw the water temperature gauge when the fan is running? :idea:

If have a chance to check that out you will have your problem sorted i think...

I think it´s difficult that the water keep that hot for a long time and capable to start up the fan!

But as Henny posted "on a G60 there is a thermo switch above the inlet manifold which controls the fan run on..."

I don´t know about the VR6. :roll:

I suspect you have a faulty sensor... :wink:

[Robbo149 0]

No, water is deffo not hot after 2-3 hours, not even registering on temp gauge.

 

I think maybe a sensor too, although I had a diagnostic done yesterday & nothing came up (apart from cam sensor error, but that's another story!)

 

Cheers,

Robbo

[dr_mat 0]

There's a timer circuit that controls the run-on. There's also a relay (I'm sure I've read this) - it's the big block with fuses in it under the bonnet on the right hand side in a VR. This relay should prevent any run-on functions occurring more than 15 minutes after the ignition was last switched off.

You *could* also have a faulty ignition switch, keeping some circuits on while the main engine supply goes off. I dunno, I'm not that hot on car electronics!! :|

 

BTW if you have a very dark coloured car it's quite possible that with the car sitting in the sun the water temp can remain high for some time, but it should cool well below the 86-odd degrees required to switch the fans on pretty quickly once the engine isn't running.

[Robbo149 0]

Dunno if it's a coincidence or not but I'm having this (possible) fan relay problem, and I've also got probs with my rear wiper not turning off (not the relay cos I've fitted a new one) ?!! See my other post.

 

Robbo

[dr_mat 0]

Hmm. Begins to sound like the ignition switch, doesn't it?

[Robbo149 0]

How can I check if it's the ignition switch? & what's involved in fitting a new one?

 

Cheers,

Robbo

[dr_mat 0]

Pain in the butt, if you ask me. I mean, it's not *hard*, just fiddly.

There's a couple of threads on changing it, so best bet is to "use the search, luke"..

[Robbo149 0]

Cheers Mat, found the 'how to'. I'm not sure if it would be the ignition switch though, as I've never had any problems starting the car.

 

BTW, my car is black, but it's done it when the it's been put away in the garage!

 

Robbo

[Kevin Bacon 5]

I've heard G60 fans stay on for quite a while after the engine has stopped, as much as 15 -20 mins on SuperCharged's. Even my Golf CL fan used to stay on for about 10 mins.

 

My VR one barely comes on at all, only when stuck in traffic and I get about 3 to 5 mins run-on if the coolant is around 100 deg when I get home from work. So 2 - 3 hours later on a VR is definitely a problem! Faulty thermo switch in the rad?

[dr_mat 0]

Faulty thermo switch in the rad?

 

I wouldn't have thought so, Kev, the run-on timer should have killed the power to the fan thermo switch circuit before that could happen.

 

From what I hear about the weirdness of symptoms of dodgy ignition switches this symptom wouldn't surprise me at ALL...

[Robbo149 0]

Something else just occurred to me which may or may not be connected - I've also been having trouble with my cat 1 alarm system recently - sometimes it'll deactivate, sometimes it won't & sets the alarm off. It's an old Foxguard, the type with the phono jack plug which plugs into a socket in the steering column. It just seems a bit wierd that all these things have started playing up at the same time!

 

Robbo

[Robbo149 0]

Bo!!ox!!! more bizarre fan behaviour on the way home from work just now.

 

I started it up & straight away the temp gauge shot up to the top & the coolant warning light started flashing! switched off & checked the coolant - ok, so I turn on the ignition (without starting), & temp gauge is fine, no warning light. As soon as I start the car up, the temp gauge shoots up again! 'Ar$e' I thinks, & drive home. Arrive home & oil temp is around 90 (coolant gauge has been at max all the while). Switch off to have another look under the bonnet & the fan kicks in! Switch ignition back on (without starting engine) & temp gauge is normal (around the 80 mark), but the fan stops. Start the engine & up goes the temp gauge again! Switch off & the fan kicks in again! & stays on for ages (even at 80 deg).

 

What's going on???!!!... help!

 

Isn't there some kind of coolant temp sensor on the block?, could this be at fault?

 

Cheers,

Robbo

[bigbluec 0]

Funny you should mention the ignition switch as i only changed that last weekend, Fun little job indeed! Hmm got me thinking how much of a coincidence would that be....