Radiator fan not kicking in

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UnsyP
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Re: Radiator fan not kicking in

Post by UnsyP »

lefty67 wrote:
21 Jul 2020, 16:17
Did the fan used to come on after your drive to work?
I wouldn't expect the fan to come on after 25miles of mway driving.
One of the only times my fan has come on was after being on the ramps with engine running for over an hour during an mot test. The other time was driving from crewe to Plymouth non stop and then queuing to get on a ferry.

It used to come on, not all the time; but mostly when in slow traffic after a good run. When I've been driving now, then come in to some traffic, it doesn't take long for the temp gauge to go quite high and the red light start flashing.

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Re: Radiator fan not kicking in

Post by Mocki »

Then after that I would expect the rad to be hot to the touch. 
It wouldn’t surprise me to find that your thermostat is fine , but that your rad is pretty much blocked , if it’s original . The coolant coming out to the bleed screw doesn’t mean the coolant is going round the cooling pipes .

you really need to get a thermometer on to this or you may just be spending more cash than you need to . 

just out of interest , is it REALLY getting that hot do you think , is the heater so hot it burns your knee ? Or is it showing very hot on the gauge ? 
not so long ago someone went to all sorts of expense and then found out the gauge sender was faulty / wrong , and infact the van wasn’t getting half as hot as they thought, the gauge was just lying to them ? 
 
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UnsyP
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Re: Radiator fan not kicking in

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Mocki wrote:
21 Jul 2020, 17:01
Then after that I would expect the rad to be hot to the touch. 
It wouldn’t surprise me to find that your thermostat is fine , but that your rad is pretty much blocked , if it’s original . The coolant coming out to the bleed screw doesn’t mean the coolant is going round the cooling pipes .

you really need to get a thermometer on to this or you may just be spending more cash than you need to . 

just out of interest , is it REALLY getting that hot do you think , is the heater so hot it burns your knee ? Or is it showing very hot on the gauge ? 
not so long ago someone went to all sorts of expense and then found out the gauge sender was faulty / wrong , and infact the van wasn’t getting half as hot as they thought, the gauge was just lying to them ? 
 

The rad was the first thing I had replaced, which was about 18 months ago. I'll get someone to check the heat coming off it. There is always hot air available under the dash, its nice and toasty; but not burning my knees. Its just showing really hot on the guage. After about 10 minutes of driving, its already up to 3/4 - 4/5th. Its just making me panic; as the last thing I need is a blown head gasket or similar. I just find it odd that it used to come on and now it doesn't. Is there anyway of forcing fluid through the rad to clear out any gunk?

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Re: Radiator fan not kicking in

Post by Mocki »

Ok, 
we need a recap here ( well I do , I’m in three of these similar conversations recently )

so new rad , new rad fan switch , not appearing to over heat if the heater temp is anything to go by , but showing hotter than is used to on the gauge , and getting there very quickly from start up ? Yes ? 

ave you changed the temp gauge sender , or been near it’s wiring prior to these issues ? 
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UnsyP
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Re: Radiator fan not kicking in

Post by UnsyP »

Mocki wrote:
21 Jul 2020, 18:24
Ok, 
we need a recap here ( well I do , I’m in three of these similar conversations recently )

so new rad , new rad fan switch , not appearing to over heat if the heater temp is anything to go by , but showing hotter than is used to on the gauge , and getting there very quickly from start up ? Yes ? 

ave you changed the temp gauge sender , or been near it’s wiring prior to these issues ? 

I'm glad your on the ball! :ok ....not touched the temp gauge sender or been anywhere near its wiring.

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Re: Radiator fan not kicking in

Post by UnsyP »

UnsyP wrote:
21 Jul 2020, 20:04
Mocki wrote:
21 Jul 2020, 18:24
Ok, 
we need a recap here ( well I do , I’m in three of these similar conversations recently )

so new rad , new rad fan switch , not appearing to over heat if the heater temp is anything to go by , but showing hotter than is used to on the gauge , and getting there very quickly from start up ? Yes ? 

Yes thats correct

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Re: Radiator fan not kicking in

Post by Mocki »

Right well then a look see at the temp sender for the gauge would be my next move, unplug it , clean up the connections , dirty connections change the resistance the gauge needs to see .

Ultimately change the sender for a new one ...


it’s one of two in the thermostat housing on a late van , the one facing the front of the van ( hardest one to get to from above) is the guard sender , the other , facing the wheel is a thermoswitch for the carb heater or ECU if injection . 

I still say you should beg, borrow, buy whatever , a infrared thermometer, so you can easily see what is what along the pipes, at the rad, in the engine bay 
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UnsyP
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Re: Radiator fan not kicking in

Post by UnsyP »

Mocki wrote:
21 Jul 2020, 21:08
Right well then a look see at the temp sender for the gauge would be my next move, unplug it , clean up the connections , dirty connections change the resistance the gauge needs to see .

Ultimately change the sender for a new one ...


it’s one of two in the thermostat housing on a late van , the one facing the front of the van ( hardest one to get to from above) is the guard sender , the other , facing the wheel is a thermoswitch for the carb heater or ECU if injection . 

I still say you should beg, borrow, buy whatever , a infrared thermometer, so you can easily see what is what along the pipes, at the rad, in the engine bay 

Really appreciate all the time and effort you've made with this dilemma. I will check as you've advised at some point over the next couple of days. I'll keep you updated

Thanks

Paul

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Re: Radiator fan not kicking in

Post by UnsyP »

Oh my "feck" god! After hours of reading, contemplating, reading some more. Ive plucked up the courage to replace the thermostat. Not easy to get too and was wary that the two 10ml bolts (long and short) might be ceased. Bit of patience and some WD40; and low and behold I've managed to replace the thermostat!!!! I've re filled the coolant, back and forth, undoing the bleed screw, closing the bleed screw, topping up bla bla bla......and yes! The bloody fan has come on!!!!!!!!!!! Does this now make me some sort of mechanically minded person??? Gonna take it for a quick spin. Any additional info to complete the job? Anything else I need to check? Or do I just give myself a pat on the back?

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Re: Radiator fan not kicking in

Post by Mocki »

Yes, a pat on the back to you ! 
well done sticking with it . 

plusgas would have been better than wd40 ( plusgas is a penetrating fluid , WD40 is just a water dispelling lubricant!) 

keep us updated on any developments though.......

now go have a celebratory mug of tea and a choccy biscuit!  :rofl
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UnsyP
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Re: Radiator fan not kicking in

Post by UnsyP »

Mocki wrote:
02 Aug 2020, 15:28
Yes, a pat on the back to you ! 
well done sticking with it . 

plusgas would have been better than wd40 ( plusgas is a penetrating fluid , WD40 is just a water dispelling lubricant!) 

keep us updated on any developments though.......

now go have a celebratory mug of tea and a choccy biscuit!  :rofl


I wouldn't have even got this far if it wasn't for your time, knowledge and advice; so I big thanks to you too.

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Re: Radiator fan not kicking in

Post by Mocki »

:ok
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