Vs V8 overheats with a/c on in traffic on hot days
I have not long had my VS V8 and just sorted the cooling system but it still overheats in traffic on 30decg C plus days with the A/C on, on the express way it settles down a bit but if I drive it hard it does not cool off.
Average days and at night it is faultless, thinking either the water pump is worn or the condenser thermo is tired.
Your thoughts and experiences please.
Donating Member
What do you mean when you say "just sorted the cooling system"?...do you mean new radiator/thermostat/hoses/coolant....also when you say it overheats, is that from what the gauge indicates or does the coolant actually boil and overflow?
Commodore gauges will normally run to 3/4....it's usually when they get close to the top that you really need to worry (an alarm chime will also sound...you must turn the engine off then!!).
Sorry for all the questions but without asking them any suggestions given are just stabs in the dark.
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
Yes just sorted means full flush, new radiator, thermostat, heater tap, hoses, cleaned condenser etc etc, only thing i did not do was pull the pump but flow seems ok, maybe pressed impeller and corroded??? sits on 1/4 all day now, in the heat of the moment with a/c on it will hit the chime and spew some coolant if I keep going, switch the a/c off and I can cruise and temp cools down, albeit slowly on a 40deg day.
Put it this way, if i never used the a/c i would not be complaining.
condenser thermo is working but maybe not 100% flow, how to check if it is lazy?
when i first got my vr 5ltr stato the temp gauge used to go up to half on a warm day 30 degrees even without the AC on. i found the belt that goes around water pump pulley and to the alternator was not tight enough . just loosen the mounting bolt for the alternator and loosen bolt on the adjusting bracket then lever the alternator outwards with a bar so the belt is tight , only about 10 mm deflection in belt when you push on hard with your finger , then tighten both bolts while levering on the alternator. try that b4 buying parts . if that doesnt fix it you may have to replace the fan clutch . my stato temp gauge sits on 1/4 on a hot day .
The thermostatic clutch unit in your engine fan may not be working properly and need to be replaced. The fan should almost freewheel when the engine is cold and stiffen up to full speed when the engine is warm. As the engine warms up you should hear the fan noise increase to a "roar" and then decrease in volume as the engine cools. Having said that, the standard V8 engine cooling is marginal, particularly on hot days with the air conditioning on. The service manual talks about solutions such as "changing driver behaviour" ie. turning off the A/C when stopped at traffic lights. Not a very sensible solution.
I assumed the clutch fan is working??? as there is no problem without the a/c on but that is two votes for it so will look a bit closer at it.
fan belt is ok.
Does the V8 have the extra thermo fan in front of the A/C condenser?I know some models had this fitted.Its supposed to switch on when the A/C is turned on to aid the normal cooling fan.
All V8s with A/C should have this extra thermo fan. However, its impact is marginal on a really hot day in traffic.
Donating Member
It would have to be the thermostatic fan as suggested by baz and BlackXVGTS.......bet my left te......
"If anyone disagrees with anything I say, I am quite prepared not only to retract it, but also to deny under oath that I ever said it." --T. Lehrer
"The secret of success is sincerity. Once you can fake that you've got it made." -- Jean Giraudoux
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