VT thermostat makes car overheat

[Gokz777]

I recently decided to remove my thermostat and give the whole engine and radiator a complete flush. the car was overheating from a 5 minute drive and i thought it could be a blockage or the thermostat was faulty. first i flushed out the radiator and tried to run the car again, that had no impact. So then I removed the thermostat, flushed the engine, and tried running the car again.


Engine heat using mode view (THERMO IN) - 108C - just under half. The car overheats after a drive around the block. 5 mintues? Tried putting in a new thermostat - no difference.


REMOVED THERMO

Engine heat using mode view (THERMO OUT) - 94C - quarter mark. The car temperatures rises to mid way between half and a quatre (cold end) after around 20+ minutes of driving and stays there. The car has not overheated since removing the thermostat, and that was last week.



What the hell could be causing that? I think it could be my head gasket. My oil level seems to be over full?

Im guessing its the headgasket causing pressure to build up behind the thermostat. If the headgasket is cracked then doesnt it mean water will lalso eak into the oil - explaining the high engine oil level?

[accentstencil]

Did you bleed the air out of he system? Failure to do so can result in over heating.

[PRAVX II S]

When you remove the thermostat the car wont overheat. The coolant will keep flowing through the system. The car will run cooler. If you were to take it on the highway you will notice the temp will be low.
Did you bleed the cooling system?

[S.T.K.E]

If you have a stuffed head gasket you would notice a white cream/ spermy build up around both under oil cap and under the radiator cap.

But i bet you that your problem may be with your water pump.

[VTLS1]

no creamy oil or water doesnt mean you may not have a headgasket issue. start the car with radiator cap off & check for any bubbling in the water as well. lke the blokes said you have to bleed the coolant system & remove all excess air from it. also remove your fanbelt & check your waterpump. check if there is any play in the waterpump pulley,if when spun by hand seems to turn roughly,wether theres any apparent water leakage around the waterpump. if you had a pressure tester you could also pressurize the same,if it doesnt hold pressure ou have a leak somewhere so run a dye through the system to find out where the leak is if its not obvious

[Gokz777]

iv tried bleeding the system many a time.

Remove the engine cover, turn the car on, twist the bleeder valve a little. It does not help. Every time I start the car and try to put more water into it, the water will almost always be bubbling. When the car is at half heat, and I pull over, I can hear the water under the radiator cap bubbling.

The oil is not milky BUT it does appear to be watered down i.e. if I dab the oil on paper it looks exactly like when you dab a wet paint brush on paper. You have the dark colour of the oil and then this lighter brown water colour, BUT there is ABSOLUTELY NO white or creamy colour. The oil level keeps changing. I check it always when the car is cold. Its always over full but sometimes its a hell of a lot over full and some times only a little?




The car has been pressure tested. The small pump placed onto the radiator inlet valve. Pumped it up and checked for leaks. Absolutely nothing what so ever.



No leaks
No milky ressidue in the oil


Air drained out of system
Pressure test done
Bubbling water
Engine shakes and you can feel it through the steering wheel.
Car engine heat seems ridiculously hot when opening the bonnet, even if the temp needle is under half.

There has also twice been a hissing sound coming from the where the oil is poured in. but the oil cap is fine, and on properly



Here is a video of it YouTube - VID 00002.3GP

[green5.7]

i had the same thing 3 months ago, it turned out it was the original radiator and was just block common problem , the radiator shop showed me the old ond and it was full of crud blocking the flow.

[Gokz777]

i had the same thing 3 months ago, it turned out it was the original radiator and was just block common problem , the radiator shop showed me the old ond and it was full of crud blocking the flow.

i flushed both the radiator and the engine?

[vn_v6]

a flush doesnt neccisarily get all the crud

[green5.7]

yeah i could flush the radiator too, there was still flow but not enoughe because of all the build up, i couldnt see this because i dont have x-ray vision but when the radiator was cut up i couldnt believe it.

[VT Owner]

You need to blow HP air through the radiator when you flush it to ensure all the crud comes out. The neck can be sealed using a rubber bung (you can pick one up from Clark Rubber) with a hole drilled in the centre where you can apply the HP air. Probably have to do it several times until the water runs clear out the bottom of the radiator.

[Gokz777]

You need to blow HP air through the radiator when you flush it to ensure all the crud comes out. The neck can be sealed using a rubber bung (you can pick one up from Clark Rubber) with a hole drilled in the centre where you can apply the HP air. Probably have to do it several times until the water runs clear out the bottom of the radiator.

I had it flushed till nothing but clean water was running out. I will try this, but isnt 135KPa the maximum the radiator can sustain?

The car doesnt overheat without the thermostat in. I had a pressure test performed on the radiator, not even a leak. All the hoses are in good condition.

[Gokz777]

UPDATE: Incase i didn't mention it, the heater DOES NOT blow hot air out. Only cold air

[Rubber_Burnin_Gal]

change the heater hose.......

put thermostat back in but leave the cover off, have engine running.
get a gatorade bottle, cut the bottom end off,
put the lid end(without lid) over the thermostat,
fill with water/coolant,
if the water gets sucked out of bottle, thermostat is working, if not its stuffed, replace it and the thermo gasket(all up around $20) and see if theres any difference with temp. ive just had to do the same with my VX, was over heating, so i thought id test the cheapest thing first and it was the problem! never had the A/C not blowing hot air tho?

[Gokz777]

change the heater hose.......

put thermostat back in but leave the cover off, have engine running.
get a gatorade bottle, cut the bottom end off,
put the lid end(without lid) over the thermostat,
fill with water/coolant,
if the water gets sucked out of bottle, thermostat is working, if not its stuffed, replace it and the thermo gasket(all up around $20) and see if theres any difference with temp. ive just had to do the same with my VX, was over heating, so i thought id test the cheapest thing first and it was the problem! never had the A/C not blowing hot air tho?

thanks heaps. but i think there is pressure building up behind the thermostat? had a new one put it, and the old one was still perfect. the gasket is in pretty good condition, but ill try replace that.

[bricat]

Replace radiator cap?

[Rubber_Burnin_Gal]

Replace radiator cap?

oh yeah, that too!(sorry forgot i also replaced that! LOL)

[The1]

check your heater tap it's the plastic valve on the left hand side of the engine bay looking from the front, it has 2 hoses on both ends, one end going into the firewall and the other to the engine, there will be a vacuum operated leaver on it, with the car running if you turn the heater full ball it should move the leaver one way and then full cold it should be at the other extreme, if there's no movement then either the tap is stuffed or there is a vacuum leak causing it not to operate, if the tap is stuck or come off inside it might be blocking water flow.

Also prob a good idea to do a fault code check and see if there is any other faults that the computer knows about, just do a search to find howto.

[feezals]

I am having similar issues, but havent done any testing yet besides I know that the temp shows its over heating when all the levels are fine and the engine is hot. Also now that the overheating is real bad and cant drive it the air-con isn't blowing out cold air at all.. The front right blinker stopped working, and replacing it didnt fix it, then started working all of a sudden, maybe not related.

We are going to do the fault testing tomorrow as its nearly midnight, and have the instructions.. But unable to find the instructions on how to replace the thermosat.

I would like to see if that looks stuck or not before thinking about checking the other stuff, like bleeding coolant. There is also no milky stuff and we noticed that the transmission fluid dipstick wont close - have no idea if that is related.

[codeunknown]

well if the engine has overheated and safety release on air con compressor has active let out the gas....
to protect it....

themostates either work or dont....so take it out drop in some boiling water make sure the water temp is at the opening point
and drop it in ...if it dont open at the opening point temp... throw it in the bin....

now with the safety release ----pressure bypass on a new themo....
you notice you have a small hole....like 2 mm with tiny twist valve....

if your smart the first thing you do with a new themo..take the twist restricter out..cut it off...
and in fact you can drill the hole to large size..i do...
and i drill them 2 X biger..

this will mean water will get threw but not fast...the bulk will be thermo...

second thing you should be checking is blockage in the engine..with a hose of water and air pressure

third thing is the water pump...if the cars 10 years old remove and replace the water pump and fan belt if not new...

that leaves you with hoses and clamps...overflow tank and rad and rad cap...

flush out the heater core...the usual place of rust and junk in the rad...
remove the pipes in and out switch to open first and blast it out with water and air...

clean the block
clean the rad...
flush and clean the overflow tank...

get a bucket fill 50 50 water and coolant
put everything back and check for leaks while you refil the overflow tank and rad
now start the car and open the rad cap/....
everytime the water runs low make sure the hose is going flat out and fill that rad...
after 5 mins the themo should be open...
the cycle game of filling the rad should be over...as it cycles it be one min low next min high and spitting!
now fill the rad..and put the cap on

take for a 10 km run
if it never goes past 2nd section off cold..just under the water mark icon...its done and fixed

over night let it rest
and check when cold the next day the water rad...
it should take no more than 100-200mls
its fixed
keep the water in the rad full and overflow in the middle of high and low..
top up little amouts with coolant ..large amounts with 50 50 coolant and water...

done deal !

now every week for 20 mins open the heater and let it run for while...so rusty water out clean in...
every 1 year drop and flush the engine and rad and overflow...

dead easy

[codeunknown]

and if it still keeps doing it...the rad needs replacing !

[feezals]

I acidently have two posts on the issue, but I get error 48 cam angle sensor.

[feezals]

Ok called RAA - he did pressure test and was ok, but the pressure through the system showed a leak in the coolant timing cover and water pump area. He also advised us to get the fan operation checked and the aircon is not working. could be a gas leak as well, but this only just happened when car was real bad and was re-gased 3 months ago.. Now its the problem of taking it to get fixed and not get over charged. also we have fuse issues with one blinker working on and off and in some dash boards. He wasn't sure if this was linked to the air-con...