97 VS, Radiator Vs Air Con Problem?

[Miss_BB]

Hi everyone, Last weekend on a long drive i noticed that my aircon was no longer cold. I've had a feeling its been like this but its hard judging when your only doing 5 min quick trips. I put that on my list of things to do and promptly forgot about it. Now today My car ran hot. ( now reading the forum i'm not quite sure it wa actually hot ( my mechanic told me half way was too hot on a VS ) I took it straight down to the local radiator place who had a quick look but couldn't find anything wrong with it. The fan was kicking in but the temp was still climbing. All my hoses are brand new and i don't have a leak. All Gaskets were only recently done ( under warranty thank god ).

Anyway to my question. After reading all of the posts on here i am wondering if maybe something with the air con is to blame? The thermostat is getting replaced on Monday unless anything obvious comes up when the guy looks at it once its cooled down. Don't want to throw money down the drain but more importantly i need my car and its time without it that matters.

[hako]

My experience has been that the temp gauge will normally register about 1/2 normal driving in hot or cold weather in free flowing traffic or when cruising, however as soon as you either slow down or come to a halt, the gauge will fairly rapidly move up to 3/4 when the fan will kick in. If you have the A/C on, the fan will already be on but gauge reading will be the same. The gauge rapidly climbs when the car is stopped due to no airflow thru the radiator (unless the car is moving)....this is common to all cars that have electric cooling fans fitted - it saves fuel.
To check if the aircon is OK, have the engine idling with aircon off, switch aircon on and you should hear it engage and notice a slight surge in engine revs. If it's not engaging it will probably be due to low/no gas in the aircon.
However there is another little trick that can cause you aircon to be a lot less effective and this has to do with the heater tap not turning off when you dial up cold air ....the result is the aircon is supplying cold air whilst the heater is supplying hot air = warm air. You can check if this is the fault by locating the heater pipe - it's brass and sits under the dash above where your left ankle is when driving....it should be cold when the heater is off. If not it means the heater is still on.
Anyway, check the above and see how you go.

[Miss_BB]

Air con is switching on and off and getting cold intermittantly, Funny enough when the window is down the air blows cold. I think you may be right about the heater tap. It does get pretty hot near the left foot. Temp usually runs between 2 and 3 notches. when it gets to the 3rd notch the fan kicks in and drops it back to the 2nd one. This afternoon it went to just above half way. Fan running and still temp guage rising. I don't mind paying for the thermostat to be replaced if thats what the issue was. Just wanted to make sure it was nothing to do with the air con fan not working before i forked out the money. For me its more the loss of time with my car thats the problem. I live in a regional town with little pulic transport and a daughter with a physical disability. Makes my car an absolute nescessity.

[hako]

Maybe you could give replacing the thermostat a miss as it doesn't sound to me like your problem...the temp gauge will usually rise when the car is stationary. The heater tap not working is possibly the result of the vacuum hose (which controls the heater tap) getting knocked off when they changed your hoses recently....take it back to whoever fixed it and ask them if they could check it for you. There are other checks you can make yourself - another cause of the heater tap not turning off is a steel rod attached to a plastic arm that slips off and prevents the tap from turning off (near where the brass pipe is)....usually you just need to re-attach the rod to the arm.
Re the aircon switching on/off intermittently, this could be caused by low refrigerant (gas) level, bad connection somewhere, bad relay switching the compressor or the aircon fan not working (this must come on when you turn the aircon on otherwise there is no airflow over the aircon condenser located in front of the radiator...the refrigerant gas then gets very hot and the gas pressure goes high enough to trigger the high pressure switch which turns the aircon off, then it cools down and the cycle repeats itself.
Good Luck.

[BlackVXGTS]

Is your blower fan (the one in the heater unit that blows air into the car interior) working properly? If the air blows cold when the window is down, the A/C unit may be working OK but the blower fan is not blowing the cool air into the interior of the car.

[sexila]

Have you replaced the waterpump? my vs was heating up to 3/4 and didn't know why, my mate replaced the waterpump and doesnt even get to 1/2 now, the fins had basically desintergrated and not pumping the water through. pump wasn't leaking when this was happening. fuel went from 16-17 litres to 10-11 litres per 100km straight after the pump change. Must've affected the sensors somehow making it run rich.

[Miss_BB]

Just an update. Got the car back from the radiator doctors monday afternoon, new thermostat and the wiring fixed. Wiring was a little loose causing the fan to run slower than needed aparently. Thermostat looked fine but replaced anyway. Got told by mechanic that he couldn't get it over halfway once fixed but to pull over straight away if it reached 3/4s and didn't go down straight away.

Drove off with it still running one notch higher than it usually sits and took it off to the air con guy. he says slow leak hasn't had a service since 2005. ( not my fault only had the car 6 months ). This afternoon doing the school run temp reaches 3/4 and doesn't go down. Stop at kids school sitting waiting for the temp to cool down before i can get it home. On the way home ( less than 5 min drive) gets to between half and 3/4's. If the car can't handle the half hour school run then the problems not fixed. Today is a nice cool day, raining with a bloody good cool breeze.

Any other suggestions? Its not leaking coolant and for the last six months it hasn't gone above 1/4 temp.

[Brett_jjj]

Id be getting the cooling system pressure tested and the engine compression tested.These tests are cheap to get done and will tell you if there are any blown gaskets etc causing your cooling system problems.If theres no leaks found from any gaskets,and if the radiator and everything else is fine,then Id be taking into consideration what the above post says about the water pump fins on the impeller wearing away.Lately ive read quite a few posts on here about cooling system problems where the cause has been this worn pump impeller.The pump cant circulate the coolant through the engine vlock and heads fast enough because the of the worn pump impeller.There must be a lot of cheap water pumps getting about.You might want to try replacing the water pump,its not hard and they are fairly cheap.Id usually recommend that you obnly buy genuine holden parts,as they dont usually have problems like some cheaper parts,but seeing your chasing down a problem,Id buy a "cheapie" water pump from ebay and fit that and see what happens then.If it does fix it,then later on you can fit a better quality or a genuine pump.

[hako]

I'm not sure about the waterpump - I've replaced mine twice due to leaking past the shaft seal and both times the old impeller was 'as new'....made from stainless steel. Both times I bought aftermarket ones as Holden didn't have one in stock - they could get one in for $225 versus $65 for aftermarket over the counter. But then maybe you still have the original waterpump in the car. Not sure if there is an easy way to check the pumps operation without removing it.
One thing bothers me - your temp gauge going to 3/4 in traffic/slow driving with A/C is completely normal on my car and many other Commodores so as far as I can see it is "normal"....and as you've only had the car 6 months maybe it hasn't really been in hot weather??? Your remark that it has never previously gone above 1/4 may have been due to the thermostat stuck open....when the new one was installed it is designed to run the engine at around 1/3 and be wide open at 3/4 (or thereabouts)
Also why were all the gaskets replaced (first post)?
Finally, when the gauge hits 3/4, is the blast of air from the radiator very hot, and basically blowing a gale and noisy? ....this you can investigate if you lift the bonnet when it's on 3/4. If the fan is not blowing much air it may be only operating on it's low speed (2 speeds)...and if it's blowing hard but the air is warm and not hot then the radiator may be blocked or the waterpump is not circulating the coolant properly.
Good Luck.

[Miss_BB]

I've had the car running in some pretty hot days and under some pretty heavy conditions, towing etc and it only once went above the 1/3 mark. That was when i was towing and had been driving for 3 and a half hours.

When the old thermostat was pulled out it was fine, not stuck open, was merely replaced for god knows what reason by the mechanic.

The temp creeps up very slowly and the fan does run on both speeds, its more that once it gets close to the 3/4 mark it doesn't bring it down fast enough. It creeps up while i am driving around town at about 60km's an hour.


All hoses in the car are brand new and both myself and the mechanic don't believe it is any of the hoses leaking. I too was wondering about the water pump, it seems like one of the few choices left. The radiator does show a small crack that has been fixed. So i spose i could replace the radiator at the same time.

I'm just more wondering if there is anything else in the cooling system that i could be missing.

Gaskets were done under warrenty due to a run of oil leaks less than a week after i bought the car. My usual mechanic is very happy with the car and we don't suspect anything other than these cooling issues. ( in fact he says I have one of the best vs's he's ever seen and he's jealous. He and his wife own ones that aren't in as good as nick )


When i popped the bonnet when it was running at 3/4 mark this afternoon the fan wasn't running at all. Then it kicked into high speed, then low speed, then high speed, then low speed. Didn't make a huge difference to the temp though.

The car has been smelling hot for a few weeks but then again we've moved houses and i'm alot closer to the garage than i used to be.

One more thing, on occasion i have been smelling coolant through the air con system.

[hako]

Coolant in the aircon will mean the heater matrix is leaking coolant into the heater/aircon unit - it costs a lot to replace and at Hervey Bay I'd get mechanic to bypass the heater (saves about $1000!!!). The aircon will also probably run cooler with out the hot heater matrix there. The split in the radiator is not good as the plastic side tanks blow out under pressure and you lose all your coolant instantly so I'd replace that soon (~$100 on Ebay delivered)....the fan should not be switching from HI to Lo rapidly....you could ask your mechanic to 'hotwire' the fan so it runs on high speed whenever the engine is running. Another possibility is the coolant temp sensor which tells the fans when to turn on - it's next to the temp gauge sensor and has 2 wires. Also maybe swap the hi and lo fan relays around. There is a test for the sensor....think its remove sensor connector (ign on) and after 10 secs fan should automatically start on LO then 10 secs later it should switch to HI.
But first off, fix the radiator as it's basically a time bomb (bit of over exaggeration but I had one go myself)
Good Luck.

[Miss_BB]

Hi thanks for the reply. We are replacing both the temp sensor and the coolant temp sensor this evening in the hope that that could be it. If its not then what you have suggested will be my next step. I need to track down what radiator i need before i go hunting on ebay. Autopro today quoted me close to $300 for a radiator. I just walked out shaking my head.

How can we bypass the heater? If its a simple job i'll get it done while everything else is tonight. I would rather not have the fan running on high constantly, When its running on high the car surges forward. ( not good when your sitting in traffic ). But if thats what it takes then thats what it takes. Mechanic is pretty happy its not the water pump or the radiator as it only overheats gradually. If it goes from dead cold ( first thing in the morning ) i can drive for about half an hour before it starts overheating. Good as i can still do the school run in the morning.

[JAAV]

As what Hako said.
I had the same problem a few weeks ago.
The AC was intermitant and low cooling, at the same time the temp was going up intermitanly... Finaly the AC died and the temp would rise to to over heat..Found the cooling fan plug/wiring at radiator was burnt. I just hard wired it and all faults gone..

The engine was running normal because the AC runs all the time in my car henc the rad fan runs all the time.

[JAAV]

Allso the hot air on my foot was from the heater tap not closing..this was due to a faulty vac controll unit, As I never use the heater I put a T piece in the vac supply hose to the dash, and feed constant vac to the tap...

[hako]

Radiators are getting cheaper every day - the cheapest on Ebay is $88 delivered : HOLDEN COMMODORE VN/VP/VR/VS V6 RADIATOR AUTO/MANUAL (eBay item 320556498488 end time 27-Feb-11 19:02:04 AEDST) : Cars, Bikes, Boats
But if your VS is a series 2, it will not have the push-on trans cooler fittings and you need the screw on ones which are $1 dearer: Holden VN-VP-VR-VS Commodore V6 Radiator NEW #1 Quality (eBay item 260498876974 end time 24-Mar-11 10:18:33 AEDST) : Cars, Bikes, Boats Most have 2 year warrantys.

To by-pass the heater, locate the 2 heater hoses where they go thru the bulkhead and either remove from joiner and then block each end with a thick bolt/steel rod and clamp or join both hoses with some tubing and clamp securely....either way the idea is to stop coolant flowing thru the heater.
You could just run a switch to the cooling fan relay and turn it on/off from inside the car without worry about the aircon. There is a thread on this which I can locate if you are interested.