Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Sudden water temperature spikes

leonz1982

New Member
Joined
Jun 15, 2012
Messages
42
Reaction score
0
Points
0
Age
38
Location
Australia
Members Ride
VX Series 2 V6 Commodore Lumina
I have got a 2001 VX Commodore V6 Auto with 75,000km on the odo. Recently I have experienced two water temperature spikes where the gauge jumped half way above the mid line. Then I get a beeping sound from the dash with `hot` flashing. Then few seconds later the temperature return to normal. I checked that the fan is in good working order and it will come on when required and the gauge will stay at its normal position as in the picture. This happened twice in the past two days and both occasion was about 10 min driving after a cold start in the morning. then it won't happen again.

Is this a sign of something is going bad? Or is it just some sensor error? Please help and share your thought.
 

Danny

New Member
Joined
Nov 10, 2012
Messages
55
Reaction score
0
Points
0
Age
33
Location
Blue mountains
Members Ride
Soon to get WL
Sounds like air in the system look for leaks on your driveway may just need to be bled.
 

Cheap6

New Member
Joined
Jun 19, 2005
Messages
2,498
Reaction score
71
Points
0
Members Ride
VP Exec
I think it's more like a dodgy coolant temp. sensor signal. The first place I would look is the sensor connection to check that it isn't corroded or loose. It's also possible that the sensor is dying. Other than that, it could be in the wiring between the CTS and the PCM. You might see a fault in that with a visual inspection but using a DMM (Ohm meter) is better.
 

leonz1982

New Member
Joined
Jun 15, 2012
Messages
42
Reaction score
0
Points
0
Age
38
Location
Australia
Members Ride
VX Series 2 V6 Commodore Lumina
Sudden temperature spike

Danny:2444177 said:
Sounds like air in the system look for leaks on your driveway may just need to be bled.
I recently started to use the heater, and when I do I can hear the sound of water behind the console. Maybe letting the hot water into the heater core caused air to flow into the cooling system? I will try to bleed the system to see if it will fix it. thanks for the tip.
 

Dayvo

Because i can
Joined
Apr 28, 2005
Messages
2,477
Reaction score
2,841
Points
113
Location
South East,Victoria
Members Ride
VE SV6 Series 2
Try bleeding the system again . If you have air in the heater then it might have found its way to the thermostat ( as air rises ) and giving a false reading . Or maybe you have a faulty thermostat. Also check your radiator cap to make sure the seal is in good condition and the spring under the cap is working .
 

Bomber R8

New Member
Joined
Dec 2, 2012
Messages
88
Reaction score
1
Points
0
Age
39
Location
Perth
Members Ride
VXII R8 Clubsport
Was going to say it but it's already said - air in the system. Might need to bleed it more than once to get it all out.
 

leonz1982

New Member
Joined
Jun 15, 2012
Messages
42
Reaction score
0
Points
0
Age
38
Location
Australia
Members Ride
VX Series 2 V6 Commodore Lumina
Sudden temperature spike

Dayvo:2444372 said:
Try bleeding the system again . If you have air in the heater then it might have found its way to the thermostat ( as air rises ) and giving a false reading . Or maybe you have a faulty thermostat. Also check your radiator cap to make sure the seal is in good condition and the spring under the cap is working .
The thermostate was replaced about 12 months ago when I flush the cooling system. This is the 1st time I seen this happen in 12 years since I bought it. It happened again this morning 10 min after I took out of the garage and I could hear the fan started to work before the gauge reached normal working temperature. Then it will climb above the half way mark and then calmed down and stablises. The fan stopped working at this point too. From here everything goes back to normal mode throughout rest of the day/driving. Weird.... I also undone the bleed screw while it was running and hot but Ican't really see it spitting or any bubbles.
 

leonz1982

New Member
Joined
Jun 15, 2012
Messages
42
Reaction score
0
Points
0
Age
38
Location
Australia
Members Ride
VX Series 2 V6 Commodore Lumina
sudden temperature spike

magnumv8:2445018 said:
Ok, was there coolant coming from the bleed screw?
Yes, coolant flows out when I undo the screw. except the colour isnt as green as 12 months ago when I replaced the coolant.
 

mummbles

Member
Joined
Feb 21, 2010
Messages
183
Reaction score
6
Points
18
Location
Brisbane - Southside
Members Ride
VF 2 SSV Redline Sportwagon
sounds like the thermostat to me. its staying closed too long and spiking the temps. They fall to normal levels when the thermo finally opens.
 
Top