Overheating - odd symptoms

[RaptorBenn]

I have a VZ Crewman ute with the 3.6l alloytec, and its losing coolant but there are no visible leaks.
syptoms
-Air bubbles coming out coolant filler cap
-Occasional rough idle but only on start and sometimes it will go away by itself or after restart
-losing coolant/ overheating (obviously)

had the radiator water pump and thermostat changed a while ago but no difference made, and the hoses are all good.

 

[morphix]

I have a VZ Crewman ute with the 3.6l alloytec, and its losing coolant but there are no visible leaks.
syptoms
-Air bubbles coming out coolant filler cap
-Occasional rough idle but only on start and sometimes it will go away by itself or after restart
-losing coolant/ overheating (obviously)

had the radiator water pump and thermostat changed a while ago but no difference made, and the hoses are all good.

Have you checked the coolant reservoir? Any discharge/gunk on the coolant reservoir dipstick?

Could try placing cardboard under the car to see if any leaks show up by leaking onto the cardboard.

 

[MYVESSV8]

change radiator cap, these are known to fail on the vz

 

[Domowa]

Hey Mate. Here is a list that can fail on the VZ (All have happened to me lol)

*Water Pump *Bearings leak*
*Water Inlet seals (These are extremely common to leak and may be causing the issue) Picture: http://forums.justcommodores.com.au...ter-outlet-inlet-seals-img-20120225-00760.jpg
* Thermostat and Seals
* Heater Tap. Also common.

 

[RaptorBenn]

Have you checked the coolant reservoir? Any discharge/gunk on the coolant reservoir dipstick?

Could try placing cardboard under the car to see if any leaks show up by leaking onto the cardboard.

The reservoir is full but clean, and there's definitely no leaks.

 

[Dirbatua]

could be a dud thermostat not opening properly causing the system to overheat and purge coolant too.

 

[EYY]

Have the cooling system pressure tested. It could be a blown head gasket if the coolant is bubbling.

 

[RaptorBenn]

Had it changed made no difference. as far as i can tell its doing the job.

 

[petern64]

is the valley cover the same set up as an Ecotec?? because on the Ecotec the gasket deteriorates between the water jacket and exhaust port creating a path between the two ,,this happened to me ,just a thought !

 

[ilusiv1]

Yeah bro I second the coolant cap, I had a VZ crewman that the temp kept climbing too, no leakage of any type, changed the cap all sweet.