VT: Dashboard says it overheats, quickly cools down again, and then repeats. help!

[Darrellmorgan13]

Hi guys,

Really hoping someone could let me know what the most likely cause of this is as I'd love to not have to take it to a mechanic! Not that i'm that mechanically skilled, but if it's just a sensor issue or something, hopefully one of the experts on this site might be able to point me in the right direction

I own a VT Commodore (V6 Exec) which has been running great. Only problem is that it has recently began to say it's overheating. And it is doing it more and more frequently, sometimes less than a minute apart. The thermostat on the dash will rise up until its hot, beep at me and remain hot for around 15 seconds, then quickly return to the normal temperature reading. It does this regardless of how I am driving, air con or outside temperature - nothing seems to improve or worsen the frequency. It is doing it too often and cooling too fast for it to actually be overheating and the coolent levels are fine. I have noticed that at times if it has been reading 'hot' when I park that the fan will remain on for a few minutes, soon turning itself off - again, it has done this after short trips and I struggle to believe it is actually too hot.

Thanks in advance!!

Darrell

[])R@G()N]

I had the same problem it was my water pump. next time your drive it and it over heats check to see it the water pump is losing coolant

Because its hard to see if there is any leak from the weep hole in the water pump and the water runs down the front of the engine
it easier to check to see if there is any water on the top of the sump (as in pic)
you should see it there or where its been when its dried (coolent or brown water stain)

[Darrellmorgan13]

Thanks for the reply.

Thats something I hadnt thought about. So your guage was cooling down again pretty quickly as well?

[])R@G()N]

yeah just driving around town and the heat jumped straight to Hot and started flashing "Hot" and beeping on the display then down to normal temp within seconds again.

[MikeCuzzy]

Also, if you do have a leak somewhere, it's likely that there is lower levels of coolant. Mine had this problem, topped her up and it's ok now. My gauge was going all over the place.

[Cameron P]

yeah water pump and split radiator will cause your issue. and if water pump is seized the temp gauge will rise when idling

if no coolant at all is being lost as you said maybe the coolant temp sensor is faulty?

[acarmody]

Watch out for very sudden decreases in temperature, it can mean that there is no coolant in the upper radiator pipe and the sensor is measuring air. Even if coolant did flow through the engine at its maximum rate it still wouldn't bring the temperature down in mere seconds. So be careful and check your levels. Also bleed the system of all air.

[Killr6]

I had the same problem, after like 2 days of the overheating warning and stuff, mine blew and threw coolant all over the show, all because of a leak in my water pump cost me alot of $$$ because i needed a new radiator and other crap.

just go to a mechanic ask them to do a pressure test, to check for any leaks you have.