VP V6 Strange Behaviour

[azzfox]

Hey all,

Got a very strange issue! It only started a few days ago and nothing has touched beforehand.

On idle the engine fan will come on roughly every 10secs and will stay on for about 2secs before turning off. There is a 'click' noise from around the TB area (I think) before the fan comes on. It does this consistently over and over. There is no engine light and no fault codes. Then when you turn the engine off there is a slow 'hiss' noise from behind the dash for about 5secs.

This has got me scratching my head and I have no idea what is causing this strange behavior.

Any help is greatly appreciated! Thanks in advance.

[JD]

i believe the hiss behind the dash could be related to the heater ( hoses or something like that )

[azzfox]

Well its kinda like a hiss/whistle. Hard to explain. Its not very loud but its noticeable. Having thoughts maybe a vacuum leak? Would this cause the strange engine fan behavior?

[azzfox]

Thinking now maybe AC has something to do with it. That 'click' im hearing is coming from around that area and have been told that the pressure switch can trigger the thermo fan. Mums also commented that it drives like the AC is on so all signs seem to be pointing to that.

Going to have to sus it out sometime tomorrow...

[vnv8driver]

this will be when the aircon is switched on or your temperature is above half on the gauge. check both the thermofan switch for conectivity and the thermofan itself as one will need replacing. most likely the thermofan motor though by the sounds of things.

[vn calais manual]

id lean towards your air con switch mate. see how u go from there. u wont get a fault code for ur air con or engine fan motor..

[azzfox]

Had a bit of a play around today but the fan wasnt doing the strange thing anymore. Could only be when the engines cold, who knows. But also found out that the AC compressor clutch doesnt engauge (hence why the AC hasnt worked in a while ). I checked through wiring diagrams and theres 4 switches in series before the relay and compressor (main, evaporator, low and high pressure switches). Its gotta be one of the switches that has failed because the relay doesnt click when the AC button is pushed (checked fuses and swapped relays). Hmmm where to start...

[azzfox]

Well the problem is back and its getting worse. The "hiss" can be heard while driving, and its even louder outside the car. When I got home I opened the bonnet and noticed the AC clutch engaging and disengaging every few seconds and causing an unstable idle. The "hiss" seems to be coming from the AC canister thing and the "click" is the switch on the canister. I pulled one wire off the switch and all problems have stopped. The funny thing is that its doing this when the AC button isnt on, and when looking on wiring diagrams the clutch cant engauge unless the button is on. The relay has no other power source.

All I can say is WTF? Its possessed!

EDIT: The AC clutch doesnt engage full time with the AC button on. Just continues engaging/disengaging.

[azzfox]

Its possible that the AC relay is getting power from the ECU (one earth acting as supply). Apart from trying another ECU, does anyone have any idea why its doing this? Or has had this happen to them before?

Looks like im back to looking at more diagrams. Its really doing my head in!

[KiWi1]

Without reading all the replies :P

Id say its AC. mine does it, when i turn the car off, with it on.

Maybe ya button is stuffed, and stuck on??

Informative ay bro :P

Simon

[immortality]

i'd say a dodgy A/C buton or a wiring fault somewhere

[KiWi1]

You soooo just agreed with me ay :P haha Jokes.

Yep, ive got a dollar on that ay

Simon

[vp_kid]

it is ur a/c, mine does it aswell, but thats cause my hoses are punctured, didnt do it b4 they got punctured, so its definitely ur a/c, check your hoses and **** could be something alot simpler then u think.

[azkwazere]

again, AC.

Thermo fan runs when your AC does.
Clicking could be relays or the AC unit itself.

The mostly likely culrite is the AC switch but it could be a number of things.

aZk.