04 Vz Sv6 overheating, want to know your thoughts

[SirSheen]

Any help, suggestions are much appreciated. Sorry for a long post I just want to explain the whole story so who ever reads can have the best idea of what this could be. had my car sitting in the parents yard for a little bit now as it keeps overheating, a while back I blew the gearbox(auto) and something to do with that started the whole overheating problem (engine temp hot came up I pulled off the road 10 seconds later as I was in traffic and just as I turned it off I had steam goin everywhere and she was pouring at the reservoir). I took it to the mechanic to fix it and that he did, until it started overheating again. Mechanic put in a new radiator, radiator cap, serviced gearbox, flushed the hell out of the system because the blown gearbox pushed oil into the coolant I believe he refilled my power steering also. After driving around a bit one power steering hose clamp was loose and nearly killed the pump tho I was able to fill it up, tighten it, save it. Also put the car on hoist and all the bolts holding the gearbox oil pan on weren’t as tight as they could be an gearbox oil was all around it and that was very concerning, I tightened them and I tried to top it up(this could be an issue of overheating as I know it stuffs up pressure if it isn’t the right amount).

shortly after this is when it started overheating again so a few weeks after I had taken it to the mechanic, I had bought another car so that’s why I’ve been able to leave the car alone. So the car runs fine and the temperature just slowly keeps on rising til it gets to the red but I haven’t been letting it get that high, don’t want to. Any ideas ???
Next I will be changing thermostat and/or gearbox service to make sure it’s at the right amount of oil.

 

[Fu Manchu]

Bleed the air out of it.
I bet if you bought a $40 air bleed kit and did it yourself, there will be a lot of trapped air. Not all workshops will bleed the air out of the coolant correctly unless they did a vacuum fill (which also tests the integrity of the cooling system)

 

[Fu Manchu]

It’s a solid starting point and eliminates a possible cause for little to money.

If it’s the thermostat, the gearbox has to come out to get to it.

 

[greenacc]

It's amusing how often people have cooling system issues, including myself, considering how simple the cooling system really is.
If you have a new radiator and cap then start looking at air locks as above, blockages anywhere including thermostat or pump, and a dodgy new cap as this is common and a lot of non genuine caps don't hold pressure.
When the system warms up and temp gauge gets close to half can you see coolant start flowing with the radiator cap off ? If not either the pump or thermostat are stuffed or blocked. Do both the top and bottom hoses feel hot when engine gets hot? Does heater blow hot air?

 

[Fu Manchu]

These systems can’t be bleed with the use of an air bleed screw or point.

It’s a much more involved process in the Alloytec. VE and VF had a slight modification to the way air is naturally bled from the system but the down side is an even closer eye needs to be kept on the reservoir to ensure it’s not emptied as air is replaced with coolant and air reintroduced to the system causing cooling problems.

 

[rambunctious]

It's amusing how often people have cooling system issues, including myself, considering how simple the cooling system really is.
If you have a new radiator and cap then start looking at air locks as above, blockages anywhere including thermostat or pump, and a dodgy new cap as this is common and a lot of non genuine caps don't hold pressure.
When the system warms up and temp gauge gets close to half can you see coolant start flowing with the radiator cap off ? If not either the pump or thermostat are stuffed or blocked. Do both the top and bottom hoses feel hot when engine gets hot? Does heater blow hot air?

Hmmm a VZ should not run on the half mark.
We've had 5 VZ's now and they all ran about one fly poo above the 1/4 mark on the gauge, still do,
except when one split the radiator, only then did it get close to the half mark.

Temp slowly keeps rising usually indicates fans not working or radiator problem.
What about water pump ?
I know you say the mech replaced the radiator I assume with a new radiator.
Hope he didn't use second hand.

 

[SirSheen]

Hey thanks guys, so I went and properly drained the gearbox and properly filled it with oil and now it’s all sweet.

 

[Fu Manchu]