Guys,
my TM is having some overheating issues. The needle has always stayed right to the left and hardly moved. Over the last few months it has been creeping up slowly (nowhere near the red zone though) and when I get out of the traffic and start scooting along again i goes back down again.When I stop and get out the motor smells warm. I don't appear to be losing any coolant,thermostat has been replaced. Any ideas what could be causing it?

Thanks
Tools

Maate,
check the electric cooling fan (s) are working.

Cheers

Thanks MD. The fans do work , but I am wondering if they are working correctly. When I turn the motor off they will sometimes continue to run for a while if things are hot. Is this normal? How can I test to see if they are starting up at the right temp? Maybe they are taking too long to kick in.

Tools

Maate,
sounds similar to what my sons TP wagon was doing - not enough air flow over the radiator whilst sitting in traffic and the temp gauge would go to approx the halfway mark then when the vehicle was in free flowing traffic it would drop below the half way mark. The following info is from the Haynes manual:
Quote " The engine cooling fan is controlled by a radiator thermo switch located in the radiator (alongside the bottom radiator hose) and a radiator fan relay located in the engine compartment relay centre. When the coolant reaches a pre determined temperature, the switch closes, completing the fan motor relay circuit and energizing the fan" unquote.

If the vehicle is fitted with an A/C it will have an additional fan fitted in front of the condenser (front side of radiator on the passenger side).

It's worth checking the connections on the thermo switch, relay and engine temp gauge sender unit as there may be some issues there.
The contacts in the relay may also have some issues, and
Turn the fan blades by hand to see if the motor bearings are still OK


Regards

the radiator might need a flush

or replace the thermal sender that operates the fans

Magna Buff, is the thermal sender under the bottom hose what operates the fans? Where is the thermal switch then,or is there just the one? Does the temp gauge operate from this sensor as well?

Thanks
Tools

Maate,
sounds similar to what my sons TP wagon was doing - not enough air flow over the radiator whilst sitting in traffic and the temp gauge would go to approx the halfway mark then when the vehicle was in free flowing traffic it would drop below the half way mark. The following info is from the Haynes manual:
Quote " The engine cooling fan is controlled by a radiator thermo switch located in the radiator (alongside the bottom radiator hose) and a radiator fan relay located in the engine compartment relay centre. When the coolant reaches a pre determined temperature, the switch closes, completing the fan motor relay circuit and energizing the fan" unquote.

If the vehicle is fitted with an A/C it will have an additional fan fitted in front of the condenser (front side of radiator on the passenger side).Does this come on at the same time as the regular fan, or only when the Aircon is operating?

It's worth checking the connections on the thermo switch, relay and engine temp gauge sender unit(Where is the temp gauge sender unit located?) as there may be some issues there.
The contacts in the relay may also have some issues, and
Turn the fan blades by hand to see if the motor bearings are still OKFan seems smooth and quiet. I am wondering if the fan is taking too long to kick in.


Regards

Thanks for your help !
Tools

Yours sounds fairly normal to me. My first gen magnas usually ran with the temp gauge at around 35 to 40%, maybe going up as far as 50% when working hard on a hot day. That's apart from when I had various problems like burst hoses, broken water pump belt, etc.

A common cause of the radiator fan not working is the fan relay. As you know, the relays just plug into the fuse box in the engine bay. I've never had a relay actually fail but they often have poor contacts. Sometimes it helps to just unplug them and plug in again as it scrapes some of the corrosion off the lugs. All the relays in the engine bay fuse box are interchangeable, so you can swap them around to isolate the problem if you think one is faulty.

To answer some of your questions, the air cond fan only comes on when the air cond. is on. The radiator fan is turned on and off by the thermo switch in the bottom of the radiator. However it turns on and runs continuously while the air cond is on. This is handy to know. If your thermo switch is faulty, you can force the radiator fan to come on by turning on the air cond.

I've never had a TN but the radiator fan in my TM used to run for a while after switching off the engine. Neither of my TPs do that.

I think the temp gauge sender is on the inlet manifold, at least on efi models (not sure whether it is on top or underneath).

Maate,
The following info is from the Haynes manual:
Quote " The engine cooling fan is controlled by a radiator thermo switch located in the radiator (alongside the bottom radiator hose) and a radiator fan relay located in the engine compartment relay centre. When the coolant reaches a pre determined temperature, the switch closes, completing the fan motor relay circuit and energizing the fan" unquote.
Regards

the temp guage sender is seperate and located on the inlet manifold
passenger side

Hmmm

You dont think that because the temperature of the day is 20 degrees hotter in summer than in winter, that it may have something to do with the temperature rising while you are stuck in traffic in the middle of Summer.

Just a thought:io: