[andyjw26]

Working on this car and even at motorway speed the needle creeps into the red when you rev it above 2500ish. You can get it back down to normal temp by sticking the heating on.

The timing belt, water pump and radiator have all been replaced. It has been fully serviced and coolant replaced. Not cured it. The radiator is getting hot as it should so I would imagine the thermostat is ok. The fan is coming on but at what seems a bit high temp.

My next step will be block tester and compression tester to make sure the head hasn't gone.

I am not familiar with these cars or any car with electronic thermostat and it being designed to come on at 105 seems baffling to me. Any advice or insight into what the heck is going on would be much appreciated.

 

[Brilec]

Is the cooling fan coming on?

Are you sure the thermostat is opening properly?

 

[jimmymarsbar]

It could be a dodgy sensor, you'd have to physically check the temp of the coolant or engine temp, you can use an IR thermometer.

 

[arc]

had a similar issue on my 2.0. Turns out the low speed fan was not working as conf by my pp2000. Changed the relay and cured it.

 

[reload3d]

Isn't the fan switch supposed to trigger at lower than 105 degrees? 92 degrees thermostat opening? Sounds more like thermostat issue to me.

 

[madbadandold]

The fan is two speed and is controlled by one sensor and the ecu. The low speed circuit has a resistor to lower the speed. Front bumper has to come off for access to all the circuitry.

 

[andyjw26]

Thanks for the advice everyone. I got the thermostat working temp off eurocarparts.com seems high to me as well and top of radiator is getting hot before it gets there so I reckon that might be fully open temp. I tested the compression and did a head test with that blue liquid block test kit. All seems well there. The spark plugs seemed a bit rusty like it has been running lean.

I didn't realise it was a two speed fan but I think this sounds promising as the culprit. Can I get a bit more info on how to test the? What temp should it first come on?

Since I unplugged the coil and took the fuse out for compression test I am getting 0 pollution system fault read out. What does this mean?

 

[madbadandold]

The thermostat opens at a predetermined temp. Its either shut or open and there is no inbetween. The ecu looks at the temp the sensor produces and decides which fan speed is required. If the temp is getting to the higher temp quickly then perhaps the rad is partially blocked preventing the airflow from cooling it sufficiently. You could try reverse flushing the system. Remove both top and bottom hoses at the rad and using a hose flush the rad bottom to top. You can also give the engine a flush too whilst the pipes are off. Give it a good flush till the water is nice and clear from both the rad and the engine. There is a way of checking the fans using the ppk2000 software. Check to see if anybody in your area has volunteered their services to help.

 

[Brilec]

And while you are in there, you could try blowing through the rad from the back with an air line to get all the shite out which may be stopping the cooling effect.

 

[WillNZ]

When travelling on the motorway, the cooling system should never need to use any fan cooling if the system is operating properly [unless you are travelling under heavy load like towing a heavy trailer uphill]. So forget about the fan for now and sort out the system itself.

You need to eliminate possible causes one by one. It may also be a combination of faults, so check all.
1. faulty temp sender.
2. faulty thermostat
3. air locks in the system [probably the most common cause of overheating issues]
4. water pump
5. corroded/blocked cooling system.

Do not assume that, because parts have been replaced, they are OK. New parts can be faulty right out of the box.

Using an IR thermometer is probably the quickest way of checking the heat spread across the system.

Check temps of inlet and outlet radiator hoses when engine is at operating temp. If vehicle is stationary, at operating temp, fans off, vehicle idling, there should be a few degrees difference between the 2. If there is a significant difference, there is an issue with flows. Go through 2-5 above.

 

[andyjw26]

Found a small leak in the thermostat housing so I will replace the thermostat and hopefully that is the issue. Thanks for all the help people?

 

[monty9120]

let us know how it goes. on the road at 70 your fan should never come on