temp flashes hot and then goes bak to normal temp?

[shifty_90]

got a vt series 2 where since i got it serviced about 3 months ago every now and again the temp gauge will flash up hot n then just as quick will go back and sit where temp shuld sit, in the service the mechanic changed the thermostat i am thinking this may be a faulty part as before the service it never happened. has any one else ever experianced this?

[pablo]

Yes, ....take the car back to the mechanic and tell him that you suspect a faulty thermostat has been fitted.

[crazywog]

yeh i had the same happen in mine bursons

[wrx884]

wat brand thermostat did u use?? delco i think the brand is that have been found 2 have faulty thermos new.

[rjsimmo]

stupid question but have u checked if there is a leak in the system because the exact same thing happened to me 2 weeks ago turns out the system wasnt bled properly and there was a small leek.

[shifty_90]

yeh had a smal leak fixed that, blew a hose fixed that aswell now, still happening and no longer losing any coolant so ill give the mechanic a call as soon as i get the chance, thnx for the help

[Tsunamix]

It actually sounds like a faulty temperature sender to me. Thermostats tend to fail by going open or going closed and then staying that way. So the gauge wouldnt fluctate, it would go red and stay there.

I think a faulty temp sender or a short in the temp sender cables.

[Not_An_Abba_Fan]

Sounds like you have an air lock. I bet it flashes hot at idle or slow speeds? When the revs get up it goes back down?

[shifty_90]

its done it at idle, low speeds, and low revs, havnt noticed it happen at high revs, mostly just happens when casually driving to shops and things like that

[topzone]

its done it at idle, low speeds, and low revs, havnt noticed it happen at high revs, mostly just happens when casually driving to shops and things like that

Does this happen when warming up from cold or when the engine is already hot ?

[rch-13z]

Sounds like you have an air lock. I bet it flashes hot at idle or slow speeds? When the revs get up it goes back down?

When you say air lock, you mean bubbles of air in the cooling systems? had this issue a couple of weeks ago, just when sitting at lights it would say it's hot then i'd take off and it would drop off.....

[shifty_90]

usually happens when its already hot

[Jesterarts]

I recon NAAF has it in one.

bubble in thermostat... need to bleed the cooling system.

Similar issue when I had my thermostat changed in the VX.

Easy fix is run the car, undo the screw above the thermostat until it starts releasing air, do it back up when it starts spitting alot of coolant.

Alst make sure you do this with the heater on to full heat and let the car run for like 2-3 min before hand so any bubble in the heater adn heating system have a chance to move through the system to the thermostat.

Good luck.

[shifty_90]

thanks jest might give this ago on weekend, not looking forward to spending any more money on a bloody mechanic since its bin back to him once already since the thermo change, it doesnt seem to be a major problem it wouldnt do any damage to anything would it?

[Jesterarts]

shouldn't cause any huge issues, but I would have a look at it sooner rather than later.

Because it throws out the engine temp sensor there is a chance the computer will shut the engine down on you if it thinks it's running too hot.

I drove my car around for a week before I fixed it... but yeah... see how you go this weekend and let us know.

Cheers

[shifty_90]

would any one be able to post a pic of the engine bay n highlight the thermostat so i can try the bleed out of the air bubbles and see if that fixes my problem, jus dun wanna unscrew the wrong thing?

[Not_An_Abba_Fan]

Without a pic, follow the top radiator hose to the engine, where it connects is the thermostat housing. On top of that is the bleed screw, looks a bit like a grease nipple with a hole in it.

Found a pic....

[shifty_90]

ok cool thnx for the help ill give that a go on sat wen i get a chance

[shifty_90]

jus lettin u know i tried the bleeding air from system through the thermo and so far so good havnt had any problems since weekend taking it out tonight for a bit so if i have any more problems ill let u know
thanx for all the guys

[Jesterarts]

Awesome, good to hear that mate!

[HoldenOnn]

Easy way to test the gauge is......when starting the car, put the car into diagnostic mode via the trip computer buttons. This allows you to get into more features of the trip computer and allows you to see the coolant temp in actual degrees. So when the gauge goes skywards, you can check to see if the digital is doing the same also.

Just an idea