VP Lexcen (commodore lookalike) getting hot occasionaly

[lata]

I've got a bit of a temperature problem..... thought it was only a thermostat but replaced (did test it in hot water and the old one was stuffed) but 2 weeks later it's doing it again...The only thing is it only does it occasionally, not every time I drive it....

Did a computer error check thing with the paper clip and says everything okay, starting to think it could be the coolant I have put in it doing it.... Only really started doing it when put coolant in it (bought car about 18 mths ago, never had coolant in it).....

Even flushed radiator (home job) when I put coolant in it....

Please help as I am going for a long trip in a week and hope to get up there in 1 piece

[CSL]

make sure your thermo fasn is workin

[mouce]

When you say it never had coolant in it do you mean that it was just plain water? That's less than great.

Who knows how much corrosion there is in the water jacket, all good coolant concentrates have corrosion inhibiters in them. There could be crud floating around in there and it could just be blocking and clearing in parts. If you did a reverse flush of the block/radiator then you could have dislodged a lot of crap that may be just floating around in there now.

More to the point though, how do you know it's overheating? Are you just relying on the gauge? It could just be a faulty sender.

[ScottB_33]

Different coolants can react together if mixed when refilling your radiator. I noticed that you stated that the problem seemed to occur when you changed the coolant in the vehicle. We all know you can't change the coolant totally as some will always be stuck in the heater core and block areas. Possibly the coolant you used has reacted with the old coolant and it goes like a kind of sludge blocking the tubes. I've had it before on some customers cars that have used cheap inhibitor and it reacts with the new coolant blocking the radiator with a kind of sludge. All that can be done to remedy the situation is to remove the radiator and have the sludge cleaned out of the tubes, which means the radiator must be pulled apart, cleaned and then reassembled. As long as you have blead the system of any air after changing the coolant the headgaskets should be ok!!!

[lata]

When I did the error check, it said it was okay, so I am assuming the temp sender is okay!!!! How do you bleed the air out of cooling system???? Not sure, the other half changed the thermostat so I wouldn't know what he actually did......Was only hoping it was the thermostat.....And it's not as if it does it every time I drive it....Not sure really,,, i've spent enough money on it in the last month and hoping not to have to spend too much more before I go away, Please help???

[mouce]

There are two temperature sensors, one for the ECU and one for the gauge. But I'm with you, it shouldn't be that.

[kezvn]

conect up a good qulity temp guage to water in purge tank undo very carfully then put sensor at end of guage into water have a look at water tempurature if it is ok replace temp sender unit if not replace all coolant with one brand undo all hoses on motor flush total system with water if still geting hot put gasomiter on it sniffs water for carbonmonoxide for blown headgasket just done it had headgasket blowing replaced head gaskets pr****k of job fine now hope i can help

[lata]

Wouldn't it get hot everytime i drove it if it was the head???? It's the fuel injected computerised commodores that confuse me,, like my old vb commo, so much easier to diagnose problems!!!! Can someone please tell me how to bleed the air out of thermostat (i'm female and would rather do it myself than ask the other half), is it the bit you undo with a screwdriver or do you undo the bolt under that bit???? Please help, time is running out

[lata]

Thanks for all your help, I have just taken the old girl for a drive and she seems okay (just bled the thermostat free from air) anyway, will soon let you know if that's all it was or if I still have problems... thanks heaps for alll the great info on this website...JUST COMMODORES ROX