Overheating issues...

[L-VrCalais]

Hi all

Basically like the thread title says my car seems to be telling me its overheating, but then the thermo fan kicks in and all is good. It seems to only do it after about 1/2 an hour of driving so and when sitting at lights or going up a hill, also when i was at a mechanic last getting my trans looked at he told me the car isn't running as hot as the gauge says. Also keeping in mind I cant hear boiling, smell coolant cooking and the car doesn't run rough when it says it overheats.
I also replaced the radiator 3 weeks ago, thermostat 8 months ago etc.

So anyways im guessing temp sender or sensor???

Any Ideas anyone

[tezza]

So how hot on the guage does it indicate? When the coolant was replaced, was it mixed 50/50 and bled correctly?

[The1]

the guage sensor is never accurate in vs, if the cooling fan is coming on it's the main thing, if it's staying out of the red zone all is good. There is a seperate sensor for the guage near the coolant sensor, single wire.

[L-VrCalais]

What do u mean how hot does it indicate?? it shows over 3 qaurters and yes it was premixed coolant and i bled it properly. Im a finatic about that lol.

So i just went to super cheap then and got a temp sensor put it in and now it only get up to 3 qaurters and the fans cut in so does this mean the gauge is reading right or the fans are cutting
in when the should... im not sure how it fixed it...

[The1]

Typicaly low speed fan should come on at half and full speed at 3/4 if it goes over this then there's problems, generaly it shouldn't get to 3/4 or full speed fan, if it does you might have a blockage or clogged radiator something prohibiting proper cooling.

[hako]

I'd say your car is behaving exactly as mine has for the last 7 years. Like The1 says, the gauges are only a guide and as long as it doesn't go to the red section and the fans do switch on then all is OK. Another thing to remember is that if the temperature does go ballistic, the high temperature alarm chime will sound - mine did when the waterpump froze solid and temp went to red like a rocket. The chime sounds - I stop.
The best way to tell your normal temp gauge reading is to note where it sits "most times"....use that as your standard temp gauge operating temperature....then if it gets above this mark then firstly think why.

[PRAVX II S]

high fan speed comes on only at 110 degrees. If this does not come on then the temp is under 110 degrees.
Low fan speed comes on at 104 degrees and goes of at 99 degrees

[wortus]

Is there any coolant residue in the engine bay (white deposits) and is it using any coolant? I'd suggest your radiator cap may be faulty? Is the coolant the correct type and concentration?

[L-VrCalais]

yep it was premixed when i bought it and yes ill try the cap next. But im feeling its a faulty gauge just like the mechanic said but he also
told me to change the temp sender so yea his reading was 92 degrees and the gauge was sitting at 3 qaurters and we all know this aint right... lol

[IBLOWN]

Should never go above half way.

[wortus]

yep it was premixed when i bought it and yes ill try the cap next. But im feeling its a faulty gauge just like the mechanic said but he also
told me to change the temp sender so yea his reading was 92 degrees and the gauge was sitting at 3 qaurters and we all know this aint right... lol

The coolant is maent to be 50/50 or within a close proximity to that concentration. Pre mixed coolant is fine however it has the be 50/50 and you need to totally drain the block before adding it because after flushing and draining ther is still some water in the cooling system (engine block and heater core) so the net result is far less than a 50/50 mix. the best bet is to flush and drain as much as you can making sure you get at least 6 litres out and then adding 6 litres of concentrated coolant then topping up with water. If you want to use pre mixed you have really got to drain the block.

If you can hear boiling and smell the coolant then it's getting out somewhere, if the cap is stuffed and not holding the correct pressure then the effective boiling point is reduced as it is also reduced with the incorrect concentration of the correct coolant.
I'd be draining the system and flushing it out and refilling with a concentrated coolant and then adding water and getting a new radiator cap and then see how it goes. Also you have bled the air out of the system?

I read somewhere that these engines need a 50/50 mix otherwise the coolant can boil around the valve seat area of the cylinder heads.

[tezza]

Just try another cluster if you think its the guage.

[Fred 96]

Had this same problem with my Clubsport, gauge got up into the red zone, the high temperature alarm chimed, I s..t myself, got out, hand on the radiator, cool as normal!!! No leaks anywhere, fan was running fine. Off to the shop, mechanics looked it over, tested everything, all came back as fine, what the hell?? Then someone said to check the gauge.
In the end it was tracked down to a dry joint in the dash that was causing the problem, got them all resoldered, and no more high temperature chimes!! Having this fixed, also fixed the problem with the fuel gauge not working properly.
Just something else for you to think about.

[L-VrCalais]

Just put a new temp sensor and temp sender in it and seems to have fixed the problem thanks guys for all ur advice... cheers