water temp question

[BostonNSX]

I have noticed that after idling for a certain time( I was eating icecream in the car at newburry )
the water temp became rocket high.. almost touching the red limit.. and it does touch it after a while.. and then.. when I rev it.. it lowers and goes back again??? how come? something wrong with my car?

 

[synergy004]

i had that prob

I had the same problem in my other car not the NSX. Make sure your fan is kicking on. If its not find the problem. POssible that its not getting enough air flow aswell. I changing mine in my NSX so when im in traffic i can hit a switch and keep it on to keep the car a lil cooler.

working on it now as we speak.

laters

 

[Vytas]

I've let my car idle for long periods of time and the temp guage always stayed put at slightly below the half way point. The front fans came on several times to get air flowing through the radiator but the temp guage never rose. You may want to check that your coolant level in the bottle is where it should be. Your thermostat could possibly be acting up as well. Have the system checked.

 

[nsxtasy]

I have noticed that after idling for a certain time( I was eating icecream in the car at newburry )
the water temp became rocket high.. almost touching the red limit.. and it does touch it after a while.. and then.. when I rev it.. it lowers and goes back again??? how come? something wrong with my car?

No, your car was just jealous, because you had ice cream and you didn't share.

Seriously, most cars are at a higher risk of overheating when they come to a stop and are parked, than at any other time. When driven, there is plenty of air flow through the radiator, cooling the coolant which gets pumped through the engine. Once they are parked, the coolant stops flowing (I think) and there is no air flow through the radiator, either.

 

[sjs]

Could be any of the above, but I'd guess air in the system. You need a careful bleeding of the entire cooling system. See the manual and/or info on this site (and DanO's probably) for how to do it correctly.

The reason I say this is that I gather you see a large and instantaneous drop in temperature as soon as you rev the engine or pull away from a stop. Needless to say, the coolant isn't really changing temperature that fast. So, that means the flow past the sensor has stopped and the coolant at that point is cooking. Once it starts again you get coolant from the system that is not hot and you see the quick drop on the gauge. I'm not sure wither the bubble is at the pump and therefore nothing circulates, or at the sensor so what you see is essentially steam. I’m guessing both.

BTW, if correct then the switched fan won't help. Fuid in the radiator is fine, which again is why the temp appears to drop so fast.

 

[Briank]

Traped air in the cooling system is more then likely the cause of your problem but my second thought it could be some kind of weird electrical problem. Does your head lights dim at idle ?

 

[Briank]

No, your car was just jealous, because you had ice cream and you didn't share.

Seriously, most cars are at a higher risk of overheating when they come to a stop and are parked, than at any other time. When driven, there is plenty of air flow through the radiator, cooling the coolant which gets pumped through the engine. Once they are parked, the coolant stops flowing (I think) and there is no air flow through the radiator, either.

Engine driven water pump, water is pumped all the time the engine is running.

 

[nsxtasy]

Engine driven water pump, water is pumped all the time the engine is running.

Sorry, I meant to say that cars are at the highest risk of overheating when the engine is actually turned off.