[SS-Traveller]

Originally Posted by 4x4addict

Hi Doc, I thought the Scorpio comes with a mechanical fan and not electric...

Condenser cooling fan is electric. Fuse located under steering wheel. Radiator cooling fan is on a viscous coupling.

Originally Posted by tifosikrishna

If it is loose contact... then why it occurs only in certain conditions, meaning 15 to 20 minutes drive, stop-go, temperature shoots up and comes down immediately?
And if there's a real rise in temperature because of fan not working, won't it take time for temperature to come down, even if fan starts working instantly?

Stop-go traffic means there is no airflow to the radiator / condensor, and maybe the electric fan stops running after a while due to loose contact at the fuse - once the fuse cools, contact is established and the temp comes down in a few seconds. Yes, a high speed electric fan does cool very fast, and temp can fall to normal in just a few seconds.

[tifosikrishna]

Originally Posted by SS-Traveller

Condenser cooling fan is electric. Fuse located under steering wheel. Radiator cooling fan is on a viscous coupling.

Stop-go traffic means there is no airflow to the radiator / condensor, and maybe the electric fan stops running after a while due to loose contact at the fuse - once the fuse cools, contact is established and the temp comes down in a few seconds. Yes, a high speed electric fan does cool very fast, and temp can fall to normal in just a few seconds.

That sounds convincing and hope it turns out to be true as it will be a simple fix....

Thank you so much.. will check and let you know.

[comfortablynumb]

Hi Folks,

My Scorpio had it's 30k kms servicing done 3-4 weeks ago. Apart from the maintenance items given in the manual, I also got the LHS headlight replaced under warranty as it had fogging on the inside. Even though it isn't listed in the items covered under warranty, the ASC didn't create any hassles as there were no obvious damages that might have led to the fogging. Even on closer inspection, I couldn't see any minute crack anywhere; so am a bit puzzled as to how the fogging could have occurred. Any clues?

Cheers,
Vikram

[SS-Traveller]

Originally Posted by comfortablynumb

...LHS headlight replaced under warranty as it had fogging on the inside.
...am a bit puzzled as to how the fogging could have occurred. Any clues?

Headlamps and foglamps (on the Refresh version at least) have a tendency to accumulate moisture for no reason at all - ASCs are aware of this and do replace the lamps without protest. My car's foglamps needed changing, one was replaced but the other has not been in stock for some time now. When stocks came, I was late to turn up, and was told some 70 fog lamps had already been replaced in just over a week by the ASC, and they were out of stock again!

[n.devdath]

Originally Posted by SS-Traveller

Headlamps and foglamps (on the Refresh version at least) have a tendency to accumulate moisture for no reason at all - ASCs are aware of this and do replace the lamps without protest.

Same here at Blore. The reason is poor quality of sealant used between the reflector and the fibre glass portion of the unit in the foglamp and the headlamp. Some batches of Xylos too are known to have this issue.

[4x4addict]

Is the rear parking sensor covered under warranty? One of mine has failed and it costs 2K a pop. Which is a lot of money to pay the chinese...

[comfortablynumb]

Originally Posted by 4x4addict

Is the rear parking sensor covered under warranty? One of mine has failed and it costs 2K a pop. Which is a lot of money to pay the chinese...

The manual doesn't have an explicit list of parts covered, but the Scorpio Shield booklet does. Under the "Electrical System" section, it says music system, VMS, rear demister, high mounted stop lamp, power windows and central locking are covered under extended warranty "where given as factory fitment". So they should be covered under standard warranty too. By this yardstick, the rear parking sensor should be covered under warranty too. Me thinks you might need to hint an escalation to customer care / area manager to the ASC to get it replaced, but it should get done.

Do update us on what happens.

Cheers,
Vikram

[Zed]

Originally Posted by SS-Traveller

Condenser cooling fan is electric. Fuse located under steering wheel. Radiator cooling fan is on a viscous coupling.

Stop-go traffic means there is no airflow to the radiator / condensor, and maybe the electric fan stops running after a while due to loose contact at the fuse - once the fuse cools, contact is established and the temp comes down in a few seconds. Yes, a high speed electric fan does cool very fast, and temp can fall to normal in just a few seconds.

The viscous clutch & fan that cools the radiator does has a minimum idling that ensures airflow (thru both Radiator and AC condenser) even in stop go conditions.

If the electric fan malfunctions it will result in reduced AC cooling rather than overheating of the coolant as the radiator is cooled primarily by the viscous fan and not by the electric fan.

Originally Posted by tifosikrishna

That sounds convincing and hope it turns out to be true as it will be a simple fix....

Thank you so much.. will check and let you know.

The viscous clutch & fan that cools the radiator does has a minimum idling that ensures airflow (thru both Radiator and AC condenser) even in stop go conditions.

If the electric fan malfunctions it will result in reduced AC cooling rather than overheating of the coolant as the radiator is cooled primarily by the viscous fan and not by the electric fan.

Try this - the next time the temp gauge starts going into the red zone, pull over and with the engine idling switch on the high beam \ try short bursts of the horn etc and look out for any sudden movements of the temp gauge needle. If you can spot some movements happening immediately when the hi-beam or horn is used, you can be rest assured that its an earthing problem with the electrical system. The first gen Scorpio had an earthing point somewhere near the wheel well...not sure if the design was changed in later variants.

[SS-Traveller]

Originally Posted by Zed

If the electric fan malfunctions it will result in reduced AC cooling rather than overheating of the coolant as the radiator is cooled primarily by the viscous fan and not by the electric fan.

How / why? Until the overheat trip switch / sensor cuts out the AC compressor, why would in-cabin cooling be reduced? By that time the coolant would already have overheated, wouldn't it?

[Zed]

Originally Posted by SS-Traveller

How / why? Until the overheat trip switch / sensor cuts out the AC compressor, why would in-cabin cooling be reduced? By that time the coolant would already have overheated, wouldn't it?

1. The coolant will not overheat on account of the electric fan not working (or failing) since the visco fan takes care of airflow through radiator.

2. Therefore the AC compressor 'cut-out' would be the first noticeable effect (in stop go traffic) if there is an electric fan failure since the AC condenser will be dependant on the electric fan on account of nil ram air. The Visco fan will provide some airflow thru the condenser fins but its basically the electric fan that cools the condenser.

[SS-Traveller]

Originally Posted by Zed

1. The coolant will not overheat on account of the electric fan not working (or failing) since the visco fan takes care of airflow through radiator.

The Visco fan will provide some airflow thru the condenser fins but its basically the electric fan that cools the condenser.

Do you mean the electric fan cools the condenser and viscous fan cools the radiator as separate entities? And that an electric (condenser) fan failure will not cause the coolant in the radiator to overheat?

That's not how the cooling system behaves AFAIK...

[Zed]

Originally Posted by SS-Traveller

Do you mean the electric fan cools the condenser and viscous fan cools the radiator as separate entities? And that an electric (condenser) fan failure will not cause the coolant in the radiator to overheat?

Correct.

The close proximity of the condenser and the radiator means that there is some cross influence but by design the minimum rpm of the Visco fan is sufficient to keep the engine coolant temperatures in check as long as the cooalnt level is not below the minimum mark and the radiator fins are not clogged more than what is normally observed on account of dust accumulation.

Unlike the electric fan the viscofan does not (and actually can not) stop completely. Minimum rpm is in the 500 - 800 rpm range (in disengaged mode).

[SS-Traveller]

Originally Posted by Zed

Correct.

...by design the minimum rpm of the Visco fan is sufficient to keep the engine coolant temperatures in check...

So you mean to say that the electric fan is pretty much redundant? That there's no way a car can overheat if the electric fan does not work? Worst case scenario would be inefficient in-cabin cooling by the AC?

I would suggest you try this out practically, at 40+*C temperatures - remove the electric fan fuse and see if your car overheats or not.

[Zed]

Originally Posted by SS-Traveller

So you mean to say that the electric fan is pretty much redundant? That there's no way a car can overheat if the electric fan does not work? Worst case scenario would be inefficient in-cabin cooling by the AC?

I would suggest you try this out practically, at 40+*C temperatures - remove the electric fan fuse and see if your car overheats or not.

Most front wheel drive cars have electric fans for radiator cooling. Hence disconnecting the electric fan will lead to overheating - im stating the obvious but this is the answer to your question on 'car overheating'

Most R-WD vehicles - Sumo, Scorpio, Xylo, Qualis, Innova (and also some of the premium SUVs ) have an engine powered fan normally with a viscous coupling to regulate fan speeds. In any of these vehicles you can take the electric fan out and even at max ambient limit ( 45 Deg C ) the engine will not overheat - as long as the cooling system components are in working order (thermostat, coolant pump, no cavitation \ fin damage in raditor and correct coolant level).

To make my point clearer - the Innova has no electric fan. The visco fan also doubles up as the condenser fan - this is achieved by a combining radiator design \ layout with an appropriate fan diameter and visco clutch setting.

The Safari is the exception in the pack - which uses an electric fan for Radiator cooling as well.

Summary - A R-WD vehicle with an engine driven fan is not dependant on the electric condenser fan for engine thermal management.

[4x4addict]

@SS-Traveller:

Electric fan is not redundant, but as Zed points out it is for cooling the condenser/AC gas and not for the engine per se. As you can see many people are running Thar CRDe with condenser without the additional electric fan for the condenser without any heating issues. AC will be more effective with the electric condenser fan.

In one of earlier SUV which was black in color, I felt the AC was ineffective on very hot days. On diagnosis, I found that the wiring harness for the dual condensor fans had shorted and the condensor fan was not working. Only the radiator fan was working. I never had any heating issues, but only less efficient cooling of Ac.

Going by your 40 degree logic, you can safely drive your Scorpio at 40 degree temperature without turning on the AC in which case the electric condensor fan won't come on and you still won't have any heating issues.

There is absolutely direct heat exhange between the AC cooling system and engine cooling system. AC compressor adds some more load on the engine, but that additional load of the AC compressor shouldn't cause the engine to heat in modern powerful engines. This may have been the case for older wheezier diesel engines.

Spike, can you chip in??