VZ Temp Fluctuates in Traffic

[KrisHolden]

Hello

Problem: Temp fluctuates randomly (not every time) when in stand-still traffic on 30min+ journeys. Temp raises fairly fast to the H position, a warning sounds and the system corrects itself.

So about 4 months ago, when it first happened, Kmart bled my cooling system to ensure no air bubbles were present after my temp gauge
At the time, no leaks were detected and the car went without a problem through winter on short trips.

Today, on a hot day and a long trip, and only in stand-still traffic, the temp gauge slowly crept up randomly almost to the High position which I then received a High Temp warning and the system then corrected it and dropped back to the normal temp. Occuring randomly and not all the time, I am confused by the system decided to fluctuate.

Being a VZ V6 Calais, I know the thermostat and waterpumps are common problems and so too are the radiator caps. Kmart Auto recently determined the heater tap and hose is leaking, although the coolant levels are actually ABOVE the recommended levels. No liquid found on the road. I am getting them to fix it.

Can anyone with experience through so light as to whether the heater tap and heater hose is causing this problem as Kmart thinks it will only fix it at a 60% sucess rate.
I cannot confirm a blown head gasket, though this is my worst fear. The car was always stationary when the temp went to the H position. The car was driven very lightly (revs below 2500) when the temp was elevated at around mid-way on the temp gauge.

There is also the chance of the temp sensors failing and the cooling fans are working fine. In hope to cut costs, can anyone recommend how to go about testing what to rectify this problem?


Appreicate it!

[azazeldeath]

Next time try turn on your aircon, that normally makes both fans kick in. I noticed mine would climb like mad, I saw in another post to try turn on the aircon and the temp dropped.

I was going to replace my thermostat until I saw that, now I see no point.

[KrisHolden]

Next time try turn on your aircon, that normally makes both fans kick in. I noticed mine would climb like mad, I saw in another post to try turn on the aircon and the temp dropped.

I was going to replace my thermostat until I saw that, now I see no point.

Thanks mate! Yeah, sounds like your fan system isnt working properly... though dont quote me cause Im not a mechanic.
Appreciate your response however my car continues to overheat even with the air-con. Kmart will now have my car for three days trying to work it out.
I just really dont wanna have to fork out cash to replace the thermostat or even worse the head gaskets.

I wonder if its a bad sensor whether the coolant temp readings in the service mode is what also gets affected. Does anybody know how they can test\check the sensors?

And... Is it worth me paying them to do a test to see if the head gaskets are cracked?

[azazeldeath]

It may be worth it, also remember there was also a software issue that caused the gauge to fluctuate alot as well.

If you look back even the past month you will notice the temperature issue has been done a few times lately. Not sure what its like down south but I know its warming up alot up here. So the issue will be exaggerated alot.

[KrisHolden]

It may be worth it, also remember there was also a software issue that caused the gauge to fluctuate alot as well.

If you look back even the past month you will notice the temperature issue has been done a few times lately. Not sure what its like down south but I know its warming up alot up here. So the issue will be exaggerated alot.

Brilliant. Thanks for confirming the software issue. I read that somewhere but I couldnt get it confirmed. Do you know if updating the firmware can cause any problems like make me have to re-calibrate the fuel etc.?

Im gonna call them tomorrow and have the software updated. Just more money lol

Its certainly getting hotter here in Sydney and you're right, its making the problem heaps more evident.
I just want my car back already lol

[azazeldeath]

Holden SHOULD calibrate everything for you. Though what they should do and what they do is sometimes very different things.

[KrisHolden]

Holden SHOULD calibrate everything for you. Though what they should do and what they do is sometimes very different things.

Hahaha... yeah iv been there already... and probably on one too many occasions.

I was gonna get Kmart to do them. They do a few of my cars and they usually look after me well. Ill get their opinion first n see.
I just dont think the $150 I gave em today to replace the heater tap and hose is gonna fix it

[KrisHolden]

It may be worth it, also remember there was also a software issue that caused the gauge to fluctuate alot as well.

If you look back even the past month you will notice the temperature issue has been done a few times lately. Not sure what its like down south but I know its warming up alot up here. So the issue will be exaggerated alot.

Just updating... I called Suttons Holden service today and he assured me there was never any software update regarding the temp gauge but actually the fuel gauge.

I collected my car today. I just need to wait for a good hot day to test out whether the problem is now fixed after replacing the heater tap and hose and rebleeding.
But yeah... Im not convinced its fixed and itll leave me indoors on the next hot day.

[azazeldeath]

I called Holden today they said there was an issue, but I am not entirely sure I can beleive these idiots, I asked for my mums speedo to be calibrated. They say it cant be done at all.
Then I asked what it costs for a thermostat and housing to be replaced on a 175 alloytec engine, I get told, no lie 'Holden doesn't make alloytecs try Honda' I say its in my VZ Crewman 'We don't make a Crewman I think you have the wrong number'.

So I don't know how much you can rely on things they say. Though I have found out that I must be driving a Honda Crewman S pack thats been sneakingly rebadged as holden so has every other crewman in the world. (except the chev badged ones)

[KrisHolden]

HAHAHAHA.... yeah man!

I guess the only time your car runs perfect is out of the new cars lot BEFORE its first service... if you're lucky.

[m1lky]

The thermostat could be sticking. Pretty cheap and easy to replace. I'd check fans are kicking in properly too and radiator is full with no air but sounds like you've done that already.

Temporary solution. Ac on and heater on full bore. Would hold my vs at 1/4 in traffic. Vy never goes up from 1/3 touch wood.

[KrisHolden]

The thermostat could be sticking. Pretty cheap and easy to replace. I'd check fans are kicking in properly too and radiator is full with no air but sounds like you've done that already.

Temporary solution. Ac on and heater on full bore. Would hold my vs at 1/4 in traffic. Vy never goes up from 1/3 touch wood.

haha.. maybe I shouldv got a VY if your thermostat is that easy to get to. Damn VZs have their thermos deep in the engine compartment. Cheapest quote so far is $900, but that includes the water pump too and coolant gaskets. He wanted fours hours labour and I also said I wanted genuine parts.

Thanks for the advice on the air-con with the heater on full. Guess thats one ride to look fwd to if the car overheats next on a hot day.

Im hoping theyv fixed my car today. I own another VZ and yeah it stays a little after the first quarter with very little movement.

[m1lky]

Why the hell are they on the back? Still doable if your a bit handy though for much less than you've been quoted. I probably wouldn't bother with the water pump unless it's leaking.

Location of thermostat housing on alloytec SV6 engine

[KrisHolden]

Why the hell are they on the back? Still doable if your a bit handy though for much less than you've been quoted. I probably wouldn't bother with the water pump unless it's leaking.

Location of thermostat housing on alloytec SV6 engine

lol yeah, Iv heard to replace em on the VZs are a pain in the ass
Thanks for the advice about the water pump. I only read somewhere that waterpumps soon go after replacing radiators caps and possibly thermos (not sure).

Just waiting for another hot day

[Plichta]

One of my mates dads is a long time mechanic for holden and he sed that he sees this problem A LOT. from personal experience ive seen 3 VZ work utes all do it, my SV6 did it once and my brother's VZ wagon does it a far bit also. i assumed a sticky thermostat but he told me thermostats are rarely replaced. the simplicity of it is low coolant. when theres low coolant, air bubbles tend to form quite easily in the alloytecs, thus lowering the pressure of the cooling system and making it harder for the water pump to push the coolant around. so when ur sitting in traffic, the water pump can become really ineffective at idle.

if u hold the revs at around 3-4000rpm while stationary the temp should go back to normal within about 30secs. this has seemed to work about 98% of the time.
i dont know how to fill up ur coolant to stop getting bubbles but i think the idea is to let it run for ages while ur filling it up or something.

hope that helps.

[doms1]

I have had a issue with running hot in my vz ,thought was thermostat BUT happened to be the radiator cap splitting in 2 ,the bottom bit came away from the spring and was just stuck in hole.Got a replacement today and good as gold

[KrisHolden]

I have had a issue with running hot in my vz ,thought was thermostat BUT happened to be the radiator cap splitting in 2 ,the bottom bit came away from the spring and was just stuck in hole.Got a replacement today and good as gold

Thanks mate for the advice
Next time it happens, Im doing just that no matter what others say lol
Out of curiosity, if I open the radiator does it need to be re-bled?

[doms1]

Thanks mate for the advice
Next time it happens, Im doing just that no matter what others say lol
Out of curiosity, if I open the radiator does it need to be re-bled?

Ha ha ,not sure rebleed mine seems to be aok??Wasn't looking forward to getting thermostat changed ,time to go back to a simpler car

[edals]

Why the hell are they on the back? Still doable if your a bit handy though for much less than you've been quoted. I probably wouldn't bother with the water pump unless it's leaking.

Location of thermostat housing on alloytec SV6 engine

That Thermostat has just made me hate alloytecs even more lol. I will rebuild my ecotec a million times before i go to one lol

[KrisHolden]

Ha ha ,not sure rebleed mine seems to be aok??Wasn't looking forward to getting thermostat changed ,time to go back to a simpler car

Im definetly gonna change the cap if it fails again. Ill check with them to see if itll need a re-bleed after doing so when I buy it

That Thermostat has just made me hate alloytecs even more lol. I will rebuild my ecotec a million times before i go to one lol

lol yeah, everyone's preference. Both engines have its pros and cons i guess.
I still much prefer the alloytecs