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Old 5th July 2007, 21:19   #16
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In idle......only the engine warms-up. But even the transmission, differential oil needs to be warmedup. The viscosity of the oil in these parts will be high initially in the cold condition. Once the vehicle runs for a 2Kms and above the oils warms-up and the viscosity comes down there by reducing the friction and resistance.
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Old 6th July 2007, 01:16   #17
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It is my observation too. Transmission is not smooth unless the car is moving after a cold start.
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Old 9th November 2009, 16:57   #18
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All,

is it common to expect the whole engine/body vibrations during cold starts? have observed this happening for the first start in the day from last two weeks. When I talked to the local mechanic here, he said might be due to a weak Ignition Coil ? how do I verify the electrical are working fine. Are there any standard/bench mark values against which I can verify the voltage/current levels on these electrical components

Please help me
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Old 9th November 2009, 17:03   #19
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From what I read and seen on various programs, the new generation engines are good enough to dole out performance from the word go and there is not need for any kind of warm up in normal circumstances. However, there would be certain requirements for certain extreme climatic conditions.

Having said this, I don't see or feel any difference in my ride.
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Old 9th November 2009, 17:31   #20
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Do diesel engines take longer to get to optimal working temperatures?

Unfortunately the BMW doesn't have a temperature gauge and the sea-link is about 2kms away from my house so I am always contemplating whether it is ready to pushed hard already. The Superb which is petrol has a temperature gauge and reaches optimal temperature within 2kms.
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Old 9th November 2009, 17:39   #21
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I start off immediately after starting the engine, but drive sedately untill the temp guage reaches at least 25%. Then I drive her hard. The car starts feeling better after about 10 minutes from cold start. The warm up process is super quick if you're stuck in traffic jams!

Yesterday I saw my house owner cold-starting his Alto and immediately flooring the accelerator in nuetral gear - he says that it is good for the engine and batteries. I couldn't correct him - felt he is already beyond the point of changing his perception about such things. Felt very sorry for that engine though. It was heartbreaking. The pistons were about to get thrown out of the car's exhaust.

Last edited by clevermax : 9th November 2009 at 17:42.
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Old 9th November 2009, 17:45   #22
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When I cold start the car after say 2 or 3 days, I start off immediately and engine does revv faster til it gets warm enough and then returns to normal idling range. It happens for approximately a KM of drive or even less. But then for that one KM it run without any push on accelerator pedal and have to control it through clutch and brake combination.
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Old 9th November 2009, 17:46   #23
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Quote:
Originally Posted by Sahil View Post
Do diesel engines take longer to get to optimal working temperatures?

Unfortunately the BMW doesn't have a temperature gauge and the sea-link is about 2kms away from my house so I am always contemplating whether it is ready to pushed hard already. The Superb which is petrol has a temperature gauge and reaches optimal temperature within 2kms.
Yes diesels take much longer than Petrols to warm up and this is quite clearly evident on winter morning starts. Most Diesels are considerably noisier when cold.
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Old 9th November 2009, 17:55   #24
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Hi,

This one does not have a temperature guage, has only a green and red light for cold / hot warnings. Both are off when it is in normal working range.

It takes about 0.5 to 0.75 km for the green light to go off. The car does feel better once the green light goes off.

The green light is set to go off when the temperature reaches 54 degree C (thanks to Scanguage II).
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Old 9th November 2009, 18:42   #25
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.
I follow a slightly different approach. I treat my car like an extension of my own body.

Imagine you are in deep slumber and the alarm bell rings.
Just as we don't like to get up instantly & take sometime to warm up before we can go about our daily chores, at our optimum speed. The same principle applies to Cars.

Upon slotting the key in the Ignition ON position (All accessories work, but the engine is off!).

I wait for the slight humming noise (Fuel pump at work) to go away, it does so in about 8-10 seconds.

After this I start the car and wait till the RPM settles just a notch below or at the 1000RPM mark depending upon the time I have.

Then I start driving, I drive her sedately for about 5 kms.
The Air-conditioner is switched on, once the car has been driven for about a Kilometer or 2, till then both the front windows are open. (Fresh air is good for health & allows replacing the stale air in the car)



P.S.: No car will give the optimum performance or efficiency while being in a cold state, thats why the concept of optimum operating temperature exists.

I follow this approach, and yes it does help in increasing / maintaining engine life.
My Accent at an age of 9 years and a bit more than 1,50,000kms on the clock still pulls like it originally used to.
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Old 11th November 2009, 11:43   #26
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Follow the Owner's manual.

Start the car and drive away briskly from standstill.

Original understanding was to let all the clearances reach normal before loading the engine, but:

1. The catalytic converter doesn't work till it heats up (hence the ECU setting for running at 1100 rpm till warm, then settling down to 850-900 rpm normal idle).

2. Ricardo's has observed that the cold running conditions are so harsh that it is an imperative that all parts (including splash lubed cylinder walls ) get their lube in abundance at this stage to prevent abnormal start up wear and scouring.

Hope this helped.
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Old 12th November 2009, 10:08   #27
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On cold starts especially with diesel I let it idle for 1 minute before starting off and also let the water temperature rise upto the optimum temperature before gunning it. With petrol cars, I let it idle but push it after about 5 minutes of running.

In very cold climates, I start the vehicle let it idle for 5-10 minutes till the time white smoke has stopped and the temp gauge moved up from cold. The GB and differential oil also becomes viscous and hence generally go slow for the first 15 minutes with as much less gear changes as possible.
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Old 12th November 2009, 10:21   #28
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I wonder how many taxi-walas are following this practice of idling / not pushing too hard when engine is cold started and driven. I have seen indicab guys starting the engine in the morning and flooring the pedal all the way down may be for a 'quick heat-up'. Some guys even keep the gas pedal pressed and then crank the MPFI engine - just like the old carburetor days.

Heard from an insider that a domestic airline had to change almost a dozen of their turbo-prop engines in 10 months due to the bad throttling practices (read harsh) of two of their ex-military pilots, causing a loss of corers of rupees. I wonder how many car engines are prematurely up for repair due to negligence.
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Old 12th November 2009, 10:44   #29
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The temp needle of my Alto rests below the C position at the time of starting the engine. I will allow the engine to idle for 60 - 90 seconds till the needle points to the C mark. Then I have to drive sedately (due to traffic), cross a flyover and enter the GST road. This takes 1 KM / 5 minutes and by this time the needle points to the normal operating temperature, at which point I switch on the A/C too. The car also starts feeling "right" and handles smoothly after this point.

This practice is a hangover from my bike/carb. car days, and I feel uncomfortable not following this ritual, irrespective of what others say about it.

Last edited by Gansan : 12th November 2009 at 10:47.
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Old 12th November 2009, 11:01   #30
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Every start, I dont drive off until the RPM settles to the desired idling (800rpm) this usually takes 30 secs after cold start.
This I feel helps my car run smoother from the start. It is just my opinion and I am sure a lot of guys here will pounce on this one and ridicule !

Also, I did read somewhere that the engine suffers maximum damage at cranking and initial pull off. So may be I should wait a little longer than my usual 30 secs to ensure that the oil is near its optimum temp and levels before pulling the car off.
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