Cooling system problems

[Neil van Ek]

Greetings everyone. I have a 11/00 VX 3.8l ecotech and am having a few problems related to the cooling system.
My problems began with a blown head gasket which has been repaired. After replacing the head gaskets, I decided to revitalise the cooling system. I replaced all the hoses, the radiator, the thermostat and the radiator cap. Since replacing everything associated with the cooling syste, I have had an issue with the check engine light coming on whenever the temperature gauge gets to just below the half mark. Should I be replacing the temp sensor and the sensor that turns the fans on?
Has anyone had a similar problem and if so what was needed to rectify the problem?
Your help with sorting my cooling system problem will be greatly appreciated.

 

[Pollushon]

Your best bet is getting a scan tool to see what the trouble code is and going from there

 

[Fu Manchu]

I’m going to tell you to bleed the system with a bleed funnel, not the bloody air bleed screw.

 

[Sandst4rm]

Agree with manchu on this one the bleed screw is dog **** doesn't work at all pretty much.

Also yeah reckon go scan tool first off before anything else, always need to know what that light is on about.

 

[Fu Manchu]

https://www.ebay.com.au/itm/15X-Car...2349624.m46890.l6249&mkrid=705-154756-20017-0

You run the car through two or three thermostat opening cycles. Bleeds ALL the air out and no air pockets remain. Keep topping it up as the level drops each opening and air is bled out.

Trapped air will cause temperature spikes and problems maintaining correct cooling performance.

 

[Neil van Ek]

Thank you all for your suggestion. I haven’t had any problems bleeding the system using the bleed screw at all, but I will get myself a bleed funnel as suggested. I do have an aldl cable as well as the appropriate software for the 3.8l ecotech engine. Unfortunately it hasn’t recognised the error so I am left in the dark as to why the light keeps coming on. Guess I will just have to bite the bullet and take it to a dealership and have them plug it in and have them tell me what the problem is so I can rectify it.
My next question is, will the code clear it’s self once I repair the problem?

 

[Fu Manchu]

The very fact you are having cooling issues suggests to me that the bleed screw is insufficiently removing the trapped air.