Cooling question time again.

[Sancho]

I was driving around town last night (before anyone starts, yes, I know it was very hot) and noticed my temperature creeping up a little (about 2-3mm on the guage, you develop a good eye for it...) every now and then, then falling back down. It seemed to go up a bit when I was moving and down a bit when I was stopped. It went up the most when I got a t-junction and had to reverse a bit to let some mad man through. Would that imply that the transmission was getting hot? Am I just being an old woman?

The second thing I noticed is that my electric fan doesn't seem to come on. Ever. I have disconnected it and it works, so maybe whatever measures the temperature or whatever doesn't work. I know I could make it switchable, has anyone ever tried running it off something that measures the air temp in the engine bay? Is there any way to test it works, other than get the engine hot and see if it switches on (which I have tried).

My thanks as always.

[BUSHWHACKER]

It sounds like you have an airlock in the cooling system if the gauge is fluctuating.
The electric fan cuts in at around 100 degrees.

[Sancho]

It sounds like you have an airlock in the cooling system if the gauge is fluctuating.
The electric fan cuts in at around 100 degrees.

Thanks Vince. Surely there can't be any more air in there......

It'a not swinging around, just creeping up when I move and back down again when I stop. Still, checking the coolant level (again) and chasing any remaining air out won't hurt.

Don't know about the fan. The bonnet was too hot to touch last night. I would have thought the water was up to 100 by then (I only have the standard temp guage). Oh well, no rest for the wicked eh?

[M35A2]

Check the sender unit, it might be fu**ed. If it's like a Kenlow set up, checkthe thermostat.

My temperature needle sits rock solid right on the normal position. If anything it's a little lower when ambient air temp is very hot.

[Sancho]

Check the sender unit, it might be fu**ed. If it's like a Kenlow set up, checkthe thermostat.

My temperature needle sits rock solid right on the normal position. If anything it's a little lower when ambient air temp is very hot.

How would I check the sender and where is it? I'm about up to the level of knowing to pull the plug off the front of the stat housing and the fan goes round.

Just had a look on ebay for some kind of air temp sensor. I found a bi-metal thing that will break the circuit at 135 farenheit (about 57c) and start the fan up. What do we reckon? Is 57 too low? I think I might stick one on anyway, it only costs £1.50.

[Vagrant No2]

When you pull the wire off and the fan starts you have found the sender that is the switch . If you change that sender/switch it should then work . You can run a wire from that wire back into the cab and fit a switch to dash and the other side of the switch to earth and that will control the fan manually .

I got one of these http://cgi.ebay.co.uk/ENGINE-COOLING...QQcmdZViewItem
and it works great . I can adjust the exact temp the fans come on .

[Gazbo]

I would change your fan switch. Mine comes on all the time, in fact it surprises me at times?

[Big Jonah]

Before you go chaning things, how do you know the elctric fan should be on?

Only 2 or 3mm movement on the temp needle isn't much, and if it goes back down virtually straight away, I wouldn't worry too much.

the fact the temp falls back down when you're stationary would seem to indicate the viscous fan is working fine.

[Sancho]

Before you go chaning things, how do you know the elctric fan should be on?

Only 2 or 3mm movement on the temp needle isn't much, and if it goes back down virtually straight away, I wouldn't worry too much.

the fact the temp falls back down when you're stationary would seem to indicate the viscous fan is working fine.

Hence the 'am I being an old woman?' question....

Thing is, even when the head went and I had it in the red, still no electric fan - maybe melted the sender or something?

I do often think about the number of cars I've driven with no temperature guage, just a light that says "bad luck, you've fvcked it" and think I'm being a bit funny about it, but the feedback I've got seems to be that the needle doesn't move.

[MattF]

Hence the 'am I being an old woman?' question....

We're 2.4 owners. No such thing as too paranoid. It's the same
as I thinking that my gauge is about 1mm further to the right since
I overhauled the cooling system. Rock steady, but in a different
spot. Panic, I almost did.

With regards to the sender, connect a meter to it. The sender goes
open circuit to switch on the fan. Or, if you want to test it really quick,
connect an ohm meter to it and drop it in a pan of boiling water,
(assuming its trip temp is less than 100 degrees). The sender, not the
meter, BTW.

[Big Jonah]

If the electric fan didn't come on with the guage in the red I reckon it's u/s!

FYI I've got a 16" pacet fan, just fitted a new rad (old one was rusted away) and a new auxiallary ATF cooler. System is running sweet as now. Even a long steep hill ascent in the recent heat wave only moves the needle a mm or so, then settles right back down as soon as the hill peaks. Before, the saem hill was taking me 3/4 the way along the gauge. When sat at traffic lights, you can see the temp gauge drop to below what was my previous normal!

[Sancho]

Hypothetically speaking, if I was a lazy b@stard, is there a good reason why I shouldn't just pull the plug on the fan so it runs full time for now? Going on a fairly long trip with kids in the car soon, so I'm trying to avoid anything that might necessitate stopping and a kid going berserk.

I promise to fix it properly soon.

[POPEYE]

Your not being an old woman Sancho, cant be tooooo carefull with 2.4's, i fitted a switch in that wire and its great to have controll over it, an after market temp gauge will also help as you can see exactly what temp your running at, mine goes down a bit when i'm stopped and back up when i get going (eventuall get going lol) but the standard gauge stays constant,
its the 2.4 paranoid sydrome according to my doctor,

[Big Jonah]

Sancho, what is atually wrong with your viscous fan? If all else is working that should be ok by its self to cool you down?

[Sancho]

Nothing's wrong with the viscous fan as far as I know. It goes round and it makes a right old racket when I put my foot down so I think it's probably alright. Could probably do with refilling or whatever people do to it, but I've got no real concerns with it. Why? Should I be frightened?

I'm talking about the electric fan on the radiator that doesn't come on. Could be the sensor or whatever, maybe I should put a switch on it etc. In the meantime, whilst it's summer and I don't want to be stuck in the Malverns with a screaming kid waiting for my engine to cool down, I was wondering why I shouldn't just leave it switched on the whole time.