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maxalby
26th March 2019, 10:15 AM
The thermo-couple fan on my S4 intermittently roars, sometimes for upwards of 20 seconds, at start-up, irrespective of whether the engine is hot or cold - an irritating feature, especially in caravan parks. Is this common to all Y62's? Is there a fix?

the evil twin
26th March 2019, 10:45 AM
Common - Yes, if it doesn't there is usually something wrong

Fix - Not to my knowledge

BillsGU
26th March 2019, 12:41 PM
Not sure of the Y62 - but with some vehicles the fan comes on if the aircon is on, regardless of temp. Was your aircon on?

the evil twin
26th March 2019, 02:19 PM
Not sure of the Y62 - but with some vehicles the fan comes on if the aircon is on, regardless of temp. Was your aircon on?

The Y62 is sorta different.

The Fan on the Y62 is fully variable and is controlled by the ECU... IE it is electrically controlled, hydraulic coupled, mechanically driven.

On cold start, depending on what the ECU wants to do, the Y62 may often but not always fairly roar with fan noise for 20 seconds or more regardless of A/C


Electric / Viscous Cooling Fan
The engine driven Cooling Fan has a viscous coupling & which is electrically operated via a
signal from the ECM (via the IPDM E/R).
A Fan speed sensor which sends a signal direct to the ECM is incorporated into the hub as well.
The Fan is mounted on a pulley which is in turn driven by the auxiliary drive belt.
The Cooling Fan is driven separately to the Water Pump.

Cooling Fan Controller
The Cooling Fan Controller is integral with the Viscous Fan Hub assembly.
Following inputs such as A/C operation, A/C refrigerant pressure & engine temperature, the ECM will request the
IPDM E/R to operate the Cooling Fan Controller.
The IPDM E/R will send a command signal to the Fan Controller to provide the appropriate Cooling Fan speed.

BillsGU
26th March 2019, 09:50 PM
Hmmm ....... Glad they kept it simple. What could possibly go wrong?

the evil twin
27th March 2019, 10:26 AM
Hmmm ....... Glad they kept it simple. What could possibly go wrong?

The price one pays in this age of emissions control and min fuel consumption I spose, like that pain in the arse mongrel EGR on the oilers

FWIW, all the failures I have read about on other sources, the owners that have experienced failures of the hub etc have noticed the fan has gone to to 100%.
Annoying noise but at least the engine doesn't overheat like the ZD30's when the hub goes, time will tell tho I guess

BillsGU
27th March 2019, 12:09 PM
The price one pays in this age of emissions control and min fuel consumption I spose, like that pain in the arse mongrel EGR on the oilers

FWIW, all the failures I have read about on other sources, the owners that have experienced failures of the hub etc have noticed the fan has gone to to 100%.
Annoying noise but at least the engine doesn't overheat like the ZD30's when the hub goes, time will tell tho I guess

You are right ET in that modern vehicle technology is in the most part very reliable. The one problem is though, in the past if something failed in the more remote areas, the problem could be fixed with a bit of tape and fencing wire - or the local small town mechanic could get it going again. Nowadays it is, if you are lucky, a tow to a small town and wait for days (or weeks sometimes) for parts to arrive - or if you are unlucky, the recovery of the vehicle to a major town or city where they have specialist tools and equipment.

the evil twin
27th March 2019, 02:38 PM
True dat ^^^^

maxalby
28th March 2019, 07:34 AM
Thanks again, ET, for your excellent info. And I agree with your EGR observation......that's one of the reasons I jumped from an LC200 to the Y62, although I did install a catch can early in its life after seeing the heavy build up in a couple of 79 series ute's intake manifolds.