Overheating Carlton - BobbyDazzler
Hi all

Further to my previous posts regarding the viscous coupling fan on my 1993 2.0L cdx Carlton.

Driving in town over the last few hot days I?ve noticed the temperature guage creeping alarmingly up towards the red segment (never quite got there yet but far too close for comfort). This isn?t happening after sitting in traffic for several minutes (it never gets that busy up here!), rather it?s just normal, quite slow, driving in lower gears for maybe 5 to 10 minutes with frequent pauses (pedestrian crossing etc).

I tested the viscous coupling operation, off the car, using a hairdryer?.after it got quite hot (uncomfortable to hold) it stiffened up rather well I thought. So I figured it must be working ok.

My question is, given the dubious nature of this viscous fan (or are they all like this?), is it relatively easy to fit a standard electric fan? I?m thinking of rigging it up with a manual switch ?cos I don?t trust thermal switches either!

Do I hunt around for something big enough to fit over the existing radiator shroud (quite big) or attach a fan unit directly to the radiator somehow?

Many thanks for your help.

Overheating Carlton - SpamCan61 {P}
My 3 litre carlton had the same problem; I ended up fitting a elctric fan from a senator with a dashboard override switch. IIRC there is a depression in the valance panel near the radiator; so that the bottom of the elcectric fan is a snug fit.

VX wanted around 400 quid for a new senator fan; I got one from a breakers for 25. Can't remember what rating relay I used; but it needs to be very beefy; the fan could throw sparks an inch long when testing it with jump leads!
Overheating Carlton - BobbyDazzler
Thanks Spam

I'm off to check the thermostat just in case.

Anyone know how to bleed the system? (there are no bleed screws)
do i just run the engine with the temp sender unit out till any bubbles stop? (recently flushed the system and replaced the coolant).

Regards to all

Overheating Carlton - rileyrm
Remember in an emergency in traffic and the temp gauge creeping up to red,open windows and put heater on full,u will sweat but the temperature will drop quickly and save a hefty bill.
Overheating Carlton - Dynamic Dave
Anyone know how to bleed the system?

Pour a 50/50 mix of water/antifreeze into the header tank until up to the fill line. Run the engine & leave the rad cap off the header tank and just keep topping up until the level doesn't drop anymore. It sometimes helps to squeeze the top and bottom hoses as well as occasionally reving the engine. Wait until the top hose is warm to the touch and you'll know the thermostat is open and the coolant is circulating the whole system. Once you get to the stage of not being able to add more coolant, put the cap on and go for a reasonable drive, then park up and let the system settle for ½ hour or so. Check level again and top up if necessary. Word of caution though; if you have to top up, remove the cap slowly. Best time to check the level though is when the the engine is cold, ie, car has been left overnight. Oh yes, almost forgot, when filling, make sure your heater control knob is set to hot.
Overheating Carlton - BobbyDazzler
Many thanks to all for the advice.

Thermostat seems to be operating normally (Haynes = start opening at 92C, fully open at 107C....thats quite hot?)

Didn't have thermometer to confirm temps but could see it started to open when water began to boil so looks about right.

Refilled after thermostat check and followed your advice Dave, cheers.

John....you had/have a Carlton, how did/does your viscous fan perform in hot weather....did it cool it down ok?

Again many thanks to all

Overheating Carlton - Dizzy {P}

You could try the 'newspaper test'. Roll up a newspaper into a slightly loose cylinder and hold one end against the fan with the engine hot and running. If the newspaper stops the fan turning the viscous coupling probably needs replacing. If the fan shreds the end of the newspaper the coupling should be OK.

Viscous couplings don't always fail suddenly. The fluid in them sometimes seeps out bit by bit, almost unnoticed, until there isn't enough in there to do the job. Sometimes this can be seen by dampness on the body of the coupling which tends to collect dirt.

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