[Jaggu]

Originally Posted by star_aqua

Vikram, there are two things you can demand from the engine. torque and rpm. some applications don't care or doesn't want to affect engine speed in which they only demand the torque to sustain their load.
======
Providing an extra fan for the condenser is a workaround and NOT a solution.

Atleast you are making sense and not showing us just as Thar haters

My guess the basic issue is air flow at the radiator. Like MC said, the scorpio front is much more open allowing for better flow of air through the radiator and the engine bay?

Second the Intercooler, is also positioned on top with separate scoop to provide cool draft of air in Scorp. Since in Thar its in front of the radiator, issues might be compounded?

To redo the hood means new dye = more investment = a no go for the actual design, r&d engineers?

All of the above are wild guesses.

[esteem_lover]

Originally Posted by SPIKE ARRESTOR

Jaggu, my current age will be mostly less than or equal to the period for which you guys have been driving automobiles (I am still a novice and learning) . Regarding this AC problem, I hope it gets sorted out in the correct way.

Spike

PS- A sentence must end either with a (.) or a (?), also when in doubt ask; my school teacher taught me this.

He he he, you have a sense of humour, spikey. OK, let's stop this snake and mongoose game if we do not like the cat and mouse stuff.

Originally Posted by Jaggu

Just for AC i really don't know of any other vehicle which has 2 electric fans. But ones without engine fan, many vehicles have 2 sets of fans, and in some cases 1 separate for AC and 1 for radiator.

Providing an extra fan for the condenser is a workaround and NOT a solution.

By engine fan, I presume you are referring to the radiator fan which is also electric and not mechanical unless we are talking jeeps and very old ambys and fiats

[Mpower]

Originally Posted by star_aqua

My point is what could be the root cause for overheating. when a scorpio cannot overheat irrespective of load and environment conditions and inspite of producing more power. the same cooling system can't maintain the temperature of a lesser capacity engine which produce lesser power.
THAR engine sounds very rough compared to scorpio engine.

I have no clue. Original post suggested condenser overheating during ideal (idle?). I've never seen a AC where you monitor the temp of refrigerant!! Is it that condenser is blocking airflow to the rad which is causing the engine to overheat!

[star_aqua]

Originally Posted by Mpower

I've never seen a AC where you monitor the temp of refrigerant!! Is it that condenser is blocking airflow to the rad which is causing the engine to overheat!

Few vehicles monitor refrigerant pressure and not temperate.
my point is the THAR engine sounds rough compared to scorpio which looks like the peak combustion pressure is higher than in scorpio. a wrong pilot injection calibration could cause higher peak combustion pressure.

Originally Posted by Jaggu

My guess the basic issue is air flow at the radiator. Like MC said, the scorpio front is much more open allowing for better flow of air through the radiator and the engine bay?

Second the Intercooler, is also positioned on top with separate scoop to provide cool draft of air in Scorp. Since in Thar its in front of the radiator, issues might be compounded?

jaggu, we are talking about vehicle at standstill and engine at idle condition. so forget about ram air. and intercooler will not heat up at idle as there is no turbo.
in a THAR at least the condenser or the radiator is visible for your naked eyes. have you seen the same in scorpio?

[headers]

Originally Posted by Jaggu

1)
2) Great 413 has thermostat in the system? And its a carbed engine right? ECU gypsy with same set up of AC had heating issue, not at idle or at city traffic but only at 90 kph.

Timing right? else it will overheat!!! BTW, my 413 has no thermostat!!!

If it overheats at 90kph check the water circulation system starting from the water pump, radiator, all plumbing [there should be no acute bends etc]

Originally Posted by star_aqua

My point is what could be the root cause for overheating. when a scorpio cannot overheat irrespective of load and environment conditions and inspite of producing more power. the same cooling system can't maintain the temperature of a lesser capacity engine which produce lesser power.
THAR engine sounds very rough compared to scorpio engine.

Providing an extra fan for the condenser is a workaround and NOT a solution.

The THAR engine is bigger than the mHAWK [2.5 litre pushrod mEAGLE to a 2.2 mHawk]

The 2.2 mHAWK CRDe is a DOHC engine and is leagues ahead of the 2.5 PUSHROD CRDe engine, hence the NOISE, roughness, engine characteristics etc WILL be different. I should not be telling you this but...

Comparing this to the mHAWK is not correct!

Also the scorpio engine being smaller and having an efficient cooling system does not mean the same will work for the THAR!

I guess its the same engine in the Mahindra Tourister, M Genio etc etc.. Great Marketing

[Jaggu]

Originally Posted by esteem_lover

By engine fan, I presume you are referring to the radiator fan which is also electric and not mechanical unless we are talking jeeps and very old ambys and fiats

Yes!

Originally Posted by star_aqua

jaggu, we are talking about vehicle at standstill and engine at idle condition. so forget about ram air. and intercooler will not heat up at idle as there is no turbo.
in a THAR at least the condenser or the radiator is visible for your naked eyes. have you seen the same in scorpio?

Yup at idle it might not really matter apart from some radiating heat from the intercooler after a long run, which will get sucked in. I have seen radiator of scorpio but not closely observed, have few standing in parking lot, will check when i step out

So what is your conclusion, engine is heavily tuned in Thar avatar?

Originally Posted by headers

If it overheats at 90kph check the water circulation system starting from the water pump, radiator, all plumbing [there should be no acute bends etc]

Brand new vehicle with no mods to cooling system and a perfect system at that.

[star_aqua]

Originally Posted by headers

Comparing this to the mHAWK is not correct!

Also the scorpio engine being smaller and having an efficient cooling system does not mean the same will work for the THAR!

i was comparing the combustion noise to 2.6Crde.

[Spitfire]

Originally Posted by star_aqua

Providing an extra fan for the condenser is a
workaround and NOT a solution.

How?

Check this from the AC Installation post by BD Sir.

Condenser installation procedure

- the condenser has been specifically developed for use in Thar. The specifications mentioned herein have been arrived at after considering all possible conditions, static as well as dynamic. Hence, it is very important that the technician sticks to these guidelines during the installation. Remove the deflector assembly along with the intercooler, intercooler pipes from the vehicle. "The condenser contains a dual fan arrangement." The condenser comes with brackets which provide mounting provisions with the deflector box assembly. The relative orientation and clearances of intercooler and condenser assembly is important to ensure requisite performance. On the RHS of the deflector side panel a slot needs to be provided for routing the condenser inlet and outlet pipes, the size of the slot must be in accordance to the grommet provided in the condenser assembly. Once this step is done, the condenser is ready for assembly with the deflector. Once the intercooler, condenser and deflector box are mated together the final assembly will be ready for placement on the vehicle. The length of intercooler hoses change. While assembling the hoses proper tightening of hose with the intercooler must be ensured. Similar hoses can be used on the RH as well as LH sides. Clearances between condenser, intercooler and radiator have been defined in the design. In-order to establish good reliability with the installation, the boundary dimensions must be maintained.

Check the BOLD part in the extract. So how is it Jugaad? Its part of the design for a condenser specifically made for the THAR as per BD Sir (Mahindra).

I am guessing the Service Center goofed up in not installing that second fan at installation time considering ambient temperatures in Hyderabad.

What would be interesting to know is whether the second fan is a must in the installation? or whether it depends on other parameter. Since the ECU does not speak to these fans having both running at all times would be good to have but not an optimal solution. Something that Mahindra needs to look at.

[star_aqua]

Originally Posted by Spitfire

How?


What would be interesting to know is whether the second fan is a must in the installation? or whether it depends on other parameter. Since the ECU does not speak to these fans having both running at all times would be good to have but not an optimal solution. Something that Mahindra needs to look at.

^^^ You have answered your own question

according to me, if you are able to fix at the root, not letting the problem to occur at first place, its a solution. if you allow the problem to occur and suppress it when ever it occurs, then its a workaround.

[Spitfire]

Originally Posted by star_aqua

^^^ You have answered your own question

Yeah it was more of a what do you call those type of questions - the answer to which you already know, I cant seem to remember. I was just highlighting it.

according to me, if you are able to fix at the root, not letting the problem to occur at first place, its a solution. if you allow the problem to occur and suppress it when ever it occurs, then its a workaround.

Exactly that's how it works usually.

In this situation the Authorized guy didn't do his job as per the manual - assuming here the 12 page document says 2 fans instead of one.

So the one fan is inadequate for the condenser in Indian conditions.

I think these issues will be a bug bear since these were not tested when the vehicle itself was being tested.

Any post-production stuff even though recommended will not have gone through the stringent testing done with the product as a whole.

The feeling of being a guinea pig is not a comfortable one.

[headers]

Originally Posted by star_aqua

i was comparing the combustion noise to 2.6Crde.

@ Star Vijay: Maybe that was a different development team altogether

[star_aqua]

Originally Posted by headers

@ Star Vijay: Maybe that was a different development team altogether

Not just the team, The goal was also different.

[humyum]

Originally Posted by headers

@Jaggu: I think:

1. The ECU has no provision to increase idle rpm while ac is ON because the engine is capable of withstanding that additional load which is apparently negligible. I dont see the vehicle performance deteriorating because of this feature or the lack of it.

2. The fan installation is not clear. What I would do is to have a single electric fan in front with the required cfm rating and a single electric fan at the back of the radiator. Having 2 fans at front and making one come on at a particular temperature is fancy stuff and leads to unnecessary loads.

3. Dealer training is what M&M has to improve upon. This area has been addressed before and i'm sure they are aware of the same too.

When you add load to an engine at idle rpm like the Air conditioner, the idle rpm has to increase come what may to compensate for the increase power consumption by the AC fan (2 fans in case of the Thar), increased heat generation so more water circulation is needed by the water pump to the water jackets and to compensate for the extra load put on the engine as without the increase in RPM it will cause a vibration filled idle because of the load. Also an Engine is not producing its max power or torque at idle and the AC compressor is pulling atleast 6 to 7 BHP in case of the THAR, so without an increase in idle, it will have more chances of stalling when you start of from a standing start too. SO vehicle performance will deteriorate minus an increase in idling rpm, chances of overheating and battery not being optimially charged in traffic condtions are some of the ill effects of not increasing the idling rpm with AC.

3 liter and 4 liter diesel trucks have this increase idle rpm function and so should the THAR.

Secondly AC fan switching on and off depending on temperature is premitive stuff. My carburated 1998 800 had a temperature controlled fan the only difference being it was a single fan assembly which stayed on at all times if the AC was on and minus the AC shuffled between On and Off depending on temperature.

Thirdly M & M guys can say whatever they want, in today's generation of cars, bypassing the ECU and just connecting the AC directly is just 18th century stuff passed onto the customers. PERIOD. Would not call this an AC ready vehicles by miles.

[Mpower]

Originally Posted by star_aqua

my point is the THAR engine sounds rough compared to scorpio which looks like the peak combustion pressure is higher than in scorpio. a wrong pilot injection calibration could cause higher peak combustion pressure.

Refrigerant pressure is monitored for trouble shooting but not for normal operation, right?

Noise maybe due to the fact that Thar body has less insulation and sound deadening. Not running pilots or running fewer pilots can also cause this.

[star_aqua]

Originally Posted by Mpower

Ref pressure is monitored for trouble shooting but not always, right?

Nope, refrigerant pressure is monitored for
1) component protection, shut off of compressor in case of dry run or very high pressure
2) for controlling the condenser fan. the fan will run in different stages based on the refrigerant pressure which precisely maintain the AC performance. at this point each stage of fan should demand a predefined torque to compensate the electrical load apart from compressor load.
like this there are lot of things to be taken care for running a modern AC.