VT coolant problem

[wolvy29]

Hi all
Have a drama with my VT series 1 accliam. The temp gauge occasionally goes up to hot in a split second and the dash starts flashing hot and beeping at me and the thermo fans come on. When the car is stopped, it looks like coolant comes out of the overflow. This happens out of the bue and has no set pattern. A mechanic told me it could be a couple of things like the temp sensor.
Need help as this is frustrating me!!!!

Thanks

[dazza33]

Check this link
VX Calais strange overheating issue

Cheers, Darren.

[wolvy29]

Thanks Darren but wouldnt a crack in the radiator be easy to see?

[pablo]

If this happens occasionally with coolant loss, the engine is probably hot and boiling, the thermostat could be faulty. If there is no apparent coolant loss and no evidence of boiling, it probably would be the temperature sensor.

[jjFarking]

Could be a faulty waterpump..

[banga]

could be all of the above but a good place to start is with the thermostat , take you cover off and then the housing and replace the thermostat , its an easy job , just be sure to bleed the system before you put the cover back on, ie: when it been running for a bit after filling back up with coolant , unscrew the little brass screw in the top of the thermosta housing and wait till coolant comes out, do this while car is level , when done screw her up then take it for a 20 k drive then see how it goes , if still playing up grab a new temp sensor , this you can also do yourself , let us know how you went

[brisbane_vt]

Hi all
Have a drama with my VT series 1 accliam. The temp gauge occasionally goes up to hot in a split second and the dash starts flashing hot and beeping at me and the thermo fans come on. When the car is stopped, it looks like coolant comes out of the overflow. This happens out of the bue and has no set pattern. A mechanic told me it could be a couple of things like the temp sensor.
Need help as this is frustrating me!!!!

Thanks

This happened to me too- and it was a head gasket. combustion gas was getting into the water and bubbling away. Check for gas - open the radiator cap and a mechanic can put a device on the top of it to check for anything that should not be in the water.
Luckily for me my girlfriends dad is a non-practicing mechanic and we did it ourselves. had to re-surface the heads, buy a gasket kit, thermostat, coolant....

[wolvy29]

Thanks for your advice guys. I have changed the thermostat as I thought this would be the cheapest option but the problem still persists! I was leaning towards a faulty temp sensor but occasionally there is an overflow of coolant out of the overflow bottle. Also, dont know if this helps but occaionally I get a bubbling in the overflow bottle but no coolant coming out. I did check the radiator the other day but couldn't see any visible signs of leaking. I will get the head gasket thing checked too.

[Tsunamix]

Overflow of coolant to me means that it is getting hot for real, and not a sensor. Boiling = steam in the radiator/cooling system = pressurised system = water forced out of radiator into overflow.

Some things you can check - Rip the thermostat out and reassemble with no thermostat. Test run. It will be slow to warm up, but it prevents a blocked thermostat from being an issue.

Slacken off the serpentine belt tensioner, and make sure you can spin the water pump by hand (check for seized / stiff bearings). Do it again, placeing the end of a big screwdriver against the water pump housing, and the handle end hard into your ear. This will act like a doctors stethoscope allowing you to hear if the bearings in the pump are running rough (worn).

Obviously Drain and flush the radiator in an attempt to remove any blockages. This needs to be done several times. Some aftermarket radiator flushes need you to run it for 200KM first. Do not forget to add your radiator inhibitor after you have finished flushing. Aluminium blocks will corrode very rapidly without it.

Check that your thermo fans are working properley. Sit at idle for 10minutes, let engine hit operating temp and make sure that they are cutting in and out to maintain normal operating temp. If you have aftermarket thermos, the fan sensor may be mounted in a hose. if so, make sure that the sensor isnt sitting in a pocket of steam, instead of in the actual coolant.

Finally - One cause of overheating is over advancement of ignition. Hard to do in a modern enginie, but you can try unhooking the battery for 2 hours, reconnecting, starting and running at 2000 rpm for 30 seconds. This will throw the computer into 'learn' mode and maybe ease the problem.

Everything else is kind of major. Leaks in head gaskets, blown heads, engine blocks that are blocked (needs welch plugs pulled and block caustic cleaned) etc. Not fun and time to take it top a professional.

[Unfolded-V8]

Mine did very similiar out of no where, Found out it was the heater hose blew off, So i had to replace it too go anywhere, All fixed now

[wolvy29]

Hi guys. Just an update to say the problem has been fixed! Ended p being a sticky thermostat and me not bleeding the system properly as the water level in the radiator has to be higher than the bleeder valve or else it still has a massive air pocket in the system.

Thanks