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?

Does the fan rotate on cold start?

nope. only after

 

a, driving it a bit more harder than average driving

 

b, being stuck in traffic for more than 2-3 minutes

 

The gauge (when it is not at the lowest it goes) reads just short of midway and if i hear the fan coming one when i rev i take it easy, shove heaters on full heat and find a long stretch of road to go easy on, by the time i get to the end of the road and start driving again you cannot hear teh fan until a or b is done again.

 

just thinking that it is related to the temp sendor or the ecu temp reader (the plug i changed)

Sounds like there's a bit of confusion here!

There are 2 fans and 2 temp sensors.

 

1. Viscous fan - always turning as fixed to the engine and sound increases with revs.

When cold it slips so it doesn't do much.

2. Electric fan - in front of radiator switches on when the car gets very warm in summer etc it's loud but won't get louder with revs. Not a problem that it's coming on unless it's on all the time and your needle is heading into the red.

 

1. ECU temp sensor - big plug on radiator hard pipe that tells the ECU how warm the water is.

2. Dash temp sensor - small connector to the gauge in the dash to show you the temp but doesn't do anything else. Sounds like this is loose and making your needle drop.

Edited May 29, 200916 yr by ChrisC

hmmmmm.. so the vicous fan is the noise...... how comes i cannot hear it normally but when i accelerate in traffic or after driving in the heat?

 

it is possible it is getting hot however it was new (might be as it is hot now) and so worried me

does the coupling need replacing?

 

also if the revs are high will it do long term damage to the fan? soudnds like it doesnt like spinning that fast lol.

hmmmmm.. so the vicous fan is the noise...... how comes i cannot hear it normally but when i accelerate in traffic or after driving in the heat?

 

it is possible it is getting hot however it was new (might be as it is hot now) and so worried me

 

It's probably just the first time it's been warm enough in summer traffic jams to fully lock up and when you pull away hard in traffic is the time you'd hear it most.

Driving in the heat is exactly what it's for!

Once moving you won't hear it.

also if i am driving on a fast road and have driven a bit harder the fan can come lock in and start whirring away.. even if i have been going at 80mph the fan can sometimes stay on after i get to the end of the road..

 

i would of thought with all that cold air rushing in the front the engine would keep cool enough for the fan to uncouple.....

 

come to think about it i now have a front mounted intercooler... can that stop the engine cooling down at higher speeds as it is in the way?

Best thing is next time it happens, leave engine running and lift bonnet and move the accelerator linkage so therevs increase and then tell us which fan it is. The

one you can see in front of you or the one you can't.

 

With conflicting names for fans etc is only confusing trying to diagnose the problem for yer fella.

 

Though personally, i think the one your hearing is the eectric sub fan, which erm you shouldn't!

Check coolant levels asap.

smithy

ok i will do..

 

how much is coolant from the garage if i need some?

A litre bottle should be under a fiver mate, but just check it first and if alls well with engine running, remove the bleed screw on top of rad and see if any air is in there.

smithy

ok will do :cool:

ok can only see the biggest fan spinning... the other one i cannot see at all

ok can only see the biggest fan spinning... the other one i cannot see at all

 

That's how it should be, but which one do you thionk is making the noise that you can hear when you hav eyour probs, the one you can't see or the one you can't and more importantly there should be little or no noise from the one you can see. You will know if the other fan is running because it is somewhat noisey and has that electric fan sound.

smithy

well assuming the one i can see is running all the time it will be the other one... it is loud enough (when on) that when i rev it is as loud as the engine and i'm sure others can hear it

The one you can't see is infront of the rad under the lights center panel, as in this pic it can be seen under the air inlet hose...

 

I gotta go now, but in short if the one that's electric is running ( the one you can't see) and the air con is not on, houston, you got a problem, sozzz

Check coolant and water temp sender to ECU.

Laterz

Smithy

hmmm well i dont have aircon, taken out.. one sec ill check coolant

i have not been in the car for about 30 mins.. is it safe to take off coolant cap?

Does the viscous fan on the zed not have a "clutch" like the BMW ones?

 

It stops it from spinning at the same speed as the engine, as spinning that fast (6000rpm) can cause failer?

 

My old 7 series the clutch in the viscous locked so it spun the same speed as the engine and the plastic blades came off, one went through the bonnet and others ripped apart wiring etc!

Post edited so as not to confuse anyone ;)

 

And YES I stand corrected :bow:

Edited May 29, 200916 yr by Daves_Zed

thats what i was worried about however it isn't stuck on. it seems to disengage when it (what i think) cools down. but it certainly does get to a certain speed as it follows the revs quite high up

I beleive (and I'm sure I'm right ;) ) that that is the whole point of it being VISCOUS! When it is cold, it spins at engine speed, once it warms up it'll only spin at a predetermind speed, because the viscosity of the fluid within the fans hub warms up, and thus stops the fan from spinning any faster!

 

I'm sure someone will correct me if I'm wrong ;)

 

Other way around. As the viscous fluid warms up it releases the clutch and it begins to lock up more the hotter it gets so it will spin faster (with the engine speed).

 

When it is cold the fan spins more freely from the clutch, so the fan spins slower.

Edited May 29, 200916 yr by Yowser

so it sounds like mine is doing it's job? its been an hour. can i now check engine coolant?

Right, just to establish we're all talking the same thing here before panic sets in, lol

If the fan you can see in the engine bay is running, that's fine.

If the fan that you can't see under the centre headlight panel is running when the engine is on or even when the ignition is on, then that represents a problem, especially as you have no aircon.

Yes remove the cap slowly and you could remove the bleed screw first and see the level.

smithy

I had a similar prob as this......

The fan that you cannot see came on all the time when ignition was switched on. Turned out to be a faulty ecu chip. This might help, if not soz.

 

Al.