cooling system, overheating, i've replaced almost everything Help!!

[hako]

It's a V6
I'm liking the checking the leads, last night the tacho bounced so I'll do the leads first and let you know

I just don't really understand why it would be normal for any car to be up around 3/4 having never been there before but I feel like I'm watching the gauge more than the road because I don't want to miss if it were going to flip into the hot and I miss it!!

Will do the leads 1st!! Haven't had the heater on except to bleed it, but have only had the car since last Sept so have never used the heater in it! So help a girl out here and go further with why the rushing water sound please????

The VS Commodore ECOTEC enhancement. This means Emissions Control Optimisation TEChnology....part of this system includes running the engine at higher temperatures to burn the fuel more efficiently and reduce emissions...that's why the cooling system runs at 1.35Kpa or 20 psi which is very high and this prevents the coolant from boiling till approximately 135deg.
The rushing sound is caused by your heater tap not turning off - this means coolant flows thru the heater all the time....when you turn the selector dial to COLD, the coolant tap should turn off....yours apparently doesn't. There are a few reasons why it is not turning off so ask if you want more info. This should not make the car overheat - if anything it will keep the car cooler as the heater being on will cool the coolant. The gauge running 1/2 to 3/4 is just the gauge reading - different cars have different gauges that behave differently. If the gauge flips into the red, a warning chime "should" sound...that's if the electrics are OK...are you losing coolant?...this is important.

 

[Brett_jjj]

With my VSV6 the temp gauge never goes over half way when idling for ages or when sitting in traffic etc,the cooling fan kicks in just under half way, and drops it back to about a quarter.
Heres the actual gauge readings Vs temperature readings I get on the tech 1..
First line on temp gauge (cold) =65 degrees C.
Second line on temp gauge =87 degrees C.
Third line on temp gauge =94 degrees C.
Fourth line on temp gauge =103 degrees C.
Of course all temp gauges will be slightly different,but it gives an idea of the running temps up to when the low speed cooling fan cuts in at 104 degrees.For some unknown reason,some VS temp gauges can read up at 3/4 or more on the temp gauge before the cooling fan cuts in.

 

[tim005]

My VS V6 ute did the same thing mate, i replaced the waterpump, radiator, radiator cap, had it pressure tested, i did heaps more and it still did it.
I'm no mechanic, and i barely know what this means but my mechanic found that my welsh plug was leaking?

 

[fonzo]

LOL. mine did this....replaced every possible part of the cooling system....from the dash to the fan........still overheats

 

[Z2TT]

Guys make sure your gauge is reading right and water temp sensor is good. I had a car (Not Holden), that had receipts for every possible cooling system part replaced (Including clamps all round), turned out to be bad soldering around the dash to one of the wires going to the temp gauge, car wasn't actually overheating.

for VS, I know they run at 3/4 and this is normal, and not running "hot" so to say. As in if you install a temp guage and get the readings when the car is at 3/4. Whether this added heat makes any noticeable wear to seals or premature gasket failure, I don't know if it makes a difference. Lots of people say unless you make the fan cut in at a lower temp they will blow heads, whether that is true I don't know but somebody mentioned in the VT the fans cut in at a lower temp, so there could be some truth to it?

Should we make our VS fans cut in at a lower temp?

Thanks.

 

[Cheap6]

VT- Ecotec actually switch the cooling fan a degree or so hotter than VS.

Yes, other than as an indicator of an abnormal temp. i.e. change in operation, the dash gauge is best considered as a rough guide only.

Best to check the temp. through Tech 1 or data cable and software.

If everything else checks out as OK, an engine flush can sometimes help. The cooling passages can close up with, for want of a better term, silt (corrosion). This can both block flow and act as an insulator.