Over heating 98 vt commodore

[Tishy350]

Hi I have a 98 vt executive which keeps running out of water and getting him my temperature gauge stays on a quter and a half unless turned of. But it never moves while driving I recently replaced the thermostat and let all air out of the nipple on the housing my thermo fans don't kick in till half temp as it's got to half temp once. I'm losing so much water it's gone within an hour of driving there is no water/ cream on dipstick or in coolant bottle no leaking hoses so I'm stumped, can someone pls help me, cheers

 

[Co-Pilot]

Lots of helpful hints on this site have a look at "VT V6 Supercharged Mystery Overheating Problem" some good ideas there.
You may also have more than one bleed nipple on your system so you may not have bled air out completely.
Do you have steam coming out with your exhaust gases in the tail pipe? Is your radiator overflow tank hose broken?
See above subject re Mystery Overheating, guys there seem to know a thing or two.
Beautiful spot Deloraine, lived in Wilmot, myself but in QLD now but missing Tassie. Good luck.

 

[Nut Kracker]

If every thing else is ok as you said,
I'd say radiator cap probably.
They are an expendable item and cheap to replace.

 

[VTSS304]

Check over the radiator and look for signs of water leaks, let the car come upto temperature and lay down and check for drips under the car (remove the under cover if you have one), then trace the drips back up the engine from bottom to top and you might find your leak. As Co-Pilot mentioned check for steam from the exhaust (not on startup but after the car has warmed up) remove the engine cover and see if there is a lot of water in the "V" of the engine in the base of the intake, look for water marks down the front of the engine orignating from both the water pump and the intake area. But i would suggest starting with looking for the drips under the car and go from there as it often gives an idea of where on the engine the leak is (if the drips are right at the front of the car then check the radiator, if they are a bit further back check the front of the engine, if they are further back check the rear/top of the engine and the welsh plugs down the side)

 

[Tishy350]

No steam or anything coming out of exhaust when warmed up radiator cap dose look like it's had better days and I have noticed a drip under the radiator just can't see any hole. It drips about ever 2 seconds. Thanks for your replies I think I'll get new rad cap and water pump and have a closer look at the radiator


Sent from my iPad using Tapatalk - now Free

 

[9C1pack]

Try a cap first, as it is cheap.
VT radiators are prone to crack in the plastic side tanks. When hot the coolant may evaporate and make it difficult to spot the leak, so while the engine is cold fill the radiator, put the new cap on and start the engine and observe. They usually fail/crack on the drivers side, but check the passenger side as well.
To check the water pump, use a small mirror and angle it up under the drive pulley, it may be safer to remove the serpentine belt to do this, but remember that with the belt is off, there is no coolant being circulated so make it quick. As soon as pressure starts to build then coolant will get pushed out somewhere.
If you don't identify the leak then any radiator repair place can "pressure test it" for you, it only takes a few minutes and it should be cheap or free.