ok so after driving for 15 minutes my other fan comes on and all of a sudden the car has a louder whirring (sounds like a fan) that gets louder with more revs. If i go on a long road and drive easily the noise eventually goes until i get stuck in traffic again.

 

A few weeks ago i did change the temp sensor plug (the one on the left on the front) as the other one was taped and falling off.

 

Before i changed the new plug my temp gauge would keep cutting out and coming back on so my car would read med temp to freezing cold in split seconds.

 

It stopped for a bit however it has started doing it again... is this related to teh plug i changed or the sender? Also would the fan that keeps coming on or off (like it is overheating) be tied into the same problem with the plugs?

 

i don't have access to a pc car scan (to read temp) for a bit until santa is back so wondered what to do next when it gets hot?

mine does not start on. only after what appears to be getting hot. as in stuck in traffic or when driving hard

mine does not start on. only after what appears to be getting hot. as in stuck in traffic or when driving hard

 

That's when the fan should come on. Where's the problem??? :confused:

sounds like its doing its job then?

sounds like its doing its job then?

 

thats what i wondered i was just asking if it was normal as it is doing it more often now and i never heard it on my other 300zx and so i was worried.

 

seeing as my temp gauge keeps dropping i was just wondering if that is related and if i should be worried

also........ should it be coming on at 70- 90 mph considering the cold air that is hitting the car, i wondered if my front mounted intercooler being in the way effected the cooling

just drain and refill rad and check the ecu temp sensor isnt loosing its connection although it would run rough if it was.

 

now its summer, any overheating probs will pop up.

damo needs a coolant replacement and a bloody good flush from what i recall

thats what i wondered i was just asking if it was normal as it is doing it more often now and i never heard it on my other 300zx and so i was worried.

 

seeing as my temp gauge keeps dropping i was just wondering if that is related and if i should be worried

 

Like I said in my first post your gauge temp sensor is loose! :slap: LOL

If your temp gauge drops from normal to nothing within a couple of seconds then there is a bad connection at the temp sensor.

 

Your aux fan should only come on when the vehicle is close to overheating, its a backup safety device and should not come on if everything is ok with the cooling system.

 

It will also come on if there is a bad connection with the ECU temp sensor.

 

However the temp sender for the Dashboard gauge and the ECU temp sender are separate.

Edited May 29, 200916 yr by Yowser

thats what i wondered i was just asking if it was normal as it is doing it more often now and i never heard it on my other 300zx and so i was worried.

 

No it's not normal, so far it's been good that it's done it's job, but it's the last chance saloon. So you need to discover why. A zed can run for donkey's years without the need for it to come on.

 

We're used to sub fans coming on when using modern day cars in hot weather etc and the fan itself is designed for that, however modern day cars don't have a viscous fan!!

Smithy

No it's not normal, so far it's been good that it's done it's job, but it's the last chance saloon. So you need to discover why. A zed can run for donkey's years without the need for it to come on.

 

We're used to sub fans coming on when using modern day cars in hot weather etc and the fan itself is designed for that, however modern day cars don't have a viscous fan!!

Smithy

 

I'd say it is fairly normal.

In a stock Z standing in traffic in hot weather I've heard them come on before :confused:

Haven't heard mine since I put a huge radiator on but I've got far more water in the system now and a much bigger cooling area.

This guys got it coming on when driving though Chris, not just sat in traffic for long periods. So theres clearly something a miss somewhere as it's cut in point is in the 90's and that ain't much short of cooking a gasket on a 20 year old motor. Viscous should do pretty much 95% of all conditions and on many Zeds it does all 100% of them.

So i just want the guy to check things out before something rather nasty happens, which as you and i know means, MONEYYYYYYYYY :D

smithy

With the aircon on it will come on at 95c

With the aircon off it will com come on at 105c

update:

 

looked at radiator yesterday and a week ago it was full (granted the bloke before me used water) however yesterday it took about 2 litres or diluted anti freeze to fill up ...........

 

 

OOOOOOHHH EEEEEEEERRRRRRR!

 

i have checked it after a drive and again today and it seems to of kept its amount.... Was it because it had water it evaporated?

Was it because it had water it evaporated?

 

Not unless there is a leak fella,!

maybe... hmmmmmmmmm

 

well yesterday after topping it up i drove to southend and i was also stuck in traffic for 1.5 hours. After spending some time down there I returned to the car and checked the levels….. it was still full.

 

If I had a leak do you think that it only leaked on water? Maybe because anti freeze is thicker it wont leak? Has not leaked so far.

 

Guess I will have to inspect some more………….. shame it’s MOT this month :-(

If it had no water in it then just keep an eye on it.

yes, i will do :-)

 

unfortunately even though it is still full the noiser fan is still cuttign in rather a lot :-(

 

my car passing it's Mot looks slim this month considering

 

-still smells of over fueling

 

-one bulb has blown (not replaced as i dont drive at night)

 

-Fan cuts in alot

 

-still have a boost leak which might be playing around with the overfueling.

 

-passenger seat belt does not go all the way back properly

 

don't even know what else could be wrong... /sigh

Water can't evaporate unless it's got somewhere to go. i.e. atmosphere.

your cooling system should be sealed therefore unless you have a leak or you have allowed the water temp to rise that high that it has found a way out. You should not loose any water.

 

As the water rises in temp, it rises in pressure and will expand into your expansion tank. As it cools it's pressure drops and it will contract pulling water from the expansion tank.

 

If you are loosing water somewhere, it's likely to be doing it when the water it at it's hottest. The best thing to do to check this is open the bonnet there and under the car when the car is hot and you turn the engine off.

 

Turning the engine off stops the fans and the pump and therefore it's left to cool on it's own, which is not easy on a hot engine, therefore it may continue to heat up a little more straight after turning the engine off and therefore if it has a leak it will find it at this point.

 

Common places to look for water leaks are.

Top rad hoses. around the seal of the radiator.

Small rubber hoses mounted from the center of the engine and connect to the hardpipes that then connect ot the rad.

Heater matrix pipes at the back of the engine.

cheers for that fella.

 

i will wait until it is next hot and try that out