Hey fellas,

4afc motor in the Rola 94 model Manual.

it goes to a bit over half way on the gauge, when driving it cools down, then gets hot again when it slows down. The standard T/stat is 300k's old. It doesnt close fully.

I put a new T/stat in at first. It went straight to (just over) 1/2 way, and stayed there. No up or down. Took the new T/stat out, and put theold one back in.

 

Any ideas?

 

 

Mark

Leave the new one in?

Thermostats die, you found a dead one. you replaced it, problem solved.

 

..and then you put the old one back in?!

 

Edited October 2, 201313 yr by ke70dave

Could be dodgy temp sender.

get radiator recoed for about $120

I put a new T/stat in at first. It went straight to (just over) 1/2 way, and stayed there. No up or down.

The temperature isn't meant to change, that's the whole idea no eye deer.

when driving it cools down, then gets hot again when it slows down

 

Is that driving slowly at less than 50kph or idling?? Maybe the fans are not coming on until the temp goes up enough to trigger the fan sensor, and once they are running it cools down.

 

When you're driving at speed the airflow will keep it cool.

 

Get a real thermometer and put in in the radiator before you start the car one morning. Fire it up and let it idle until it comes up to temp. Compare the thermometer to the gauge and see what 'halfway' is in degreesC. It should run around 80deg.

Thermostats die, you found a dead one. you replaced it, problem solved.

 

..and then you put the old one back in?!

 

LMAO!!!

Why put the old one back in?

To see what -if any -difference the T/Stat made to the overheating issue.

The new thermostat is "part number correct" for this engine. Its appearance is very different to the original.

The new thermostat made the engine run slightly hotter.

I also replaced a faulty thermostat gasket.

 

Mark:)

If the old thermostat was stuck open a bit like you say, then yes its quite possible that this is why your coolant was a bit cooler all the time.

 

The thermostat aims to keep the temperature of the coolant constant. when it gets hot it opens up and lets some coolant through to the radiator, when it cools down it closes up and stops the flow to the radiator.

 

Should be around 80-85 degrees that the thermostat aims for, and under normal operating conditions, you should see the temperature rise from cold gradually, then bascially stay constant.

Yeah,

the new thermostat was working correctly, but it was running slightly hotter. But it appears substantially different to the original. It also open faster on a test (before I put it in).

I am leaning towards a slightly blocked radiator, at this stage.

 

Mark

I am leaning towards a slightly blocked radiator, at this stage.

 

It sounds like it is working at its peak capacity. Pull the rad out and flush it with a hose while upside-dowm. Blast as much water through the block as you can while the rad and t'stat are out, although a '94 shoudln't be blocked up that much. My 4K had a thick layer of rust particles in the bottom of the water jackets and bridging the waterways a lot..

 

If nothing much comes out of the radiator, it might be the water pump having corrosion issues. You might have to take that off and see what the vanes look like.

 

Put a nylon stocking over the end of the top rad hose and see if it collects anything once its all been flushed.

Thanks mate,

I guess I have more jobs to do!

 

Matrk

Pulled out all the firewall forward A/C stuff. Cool as now.

 

Thanks fellas

 

Mark!

Manuel had it right.