overheating again :(

[brendosv6]

hey guys i have an o5 sv6 couple months ago overheated mechanic to me the rad was shagged got it replaced all is fine for 3 weeks and alarms go off again take it back to the mechanic get the thermostat done now that i have it back the temp stays on 25% when im driving on the highway and in busy traffic it varys between 25% and the next bar if i turn it of and jump back in ten mins later the temp is over half and drops back down as soon as i start driving again..... the mechanic said the cats are stuffed could this be a cause of my problem someone help please im at my wits end with this beast and ive only had it 6 months

[Benboy]

Seems to me that you would be best served consulting with a radiator/cooling specialist. They can conduct a flow rate and pressure test of your cooling system. Your problem(s) may be as a result of insufficient water flow, faulty water pump, faulty thermostat etc.

[phil-v6sc-720]

yer check ur waterpump mate do u run coolant

[brendosv6]

yer mate run coolant at what stage/temp are the ac fans ment to start up

[brendosv6]

yer mate run coolant at what stage/temp are the ac fans ment to start up and is there a way to check the pump yourself??

[Dz811]

The pumps are renowned for screwing themselves, i would suggest checking those, and make sure you run RED coolant, NOT GREEN, it doesnt do the alloy block any favours, and don't mix the two either

[brendosv6]

cheers guys took to a mechanic said he thinks its an air block in the system from where he changed the thermo but im pretty sure when i paid them to do a job it was ment to be done properly but im still not buying it they said the pump woudnt be shagged because there was no water in obvious places i think its time for a new mechanic

[RiCeY]

Sounds like air lock common in the alloytechs they can be a bastard to bleed up.

[PaulSV6]

mechanic said he thinks its an air block in the system

Was just about to type that. All it takes for an Alloytech engine to overheat is just a small air pocket in the system. If the water pump was stuffed or on the way out you'll see dried coolant around the housing.

[bigdaddycool]

I had a similar issue, was caused by me not bleeding the coolant....... i followed everyone else's advice, redid it from scratch and bled it and its' been fine ever since.