does anyone let their engine run once u get to ur destination and wait a like 30 secs before turning the engine off?
benefits? bad thing to do?

 

i do... while doing that you help your engine cool down. I wait at least a min so i know for sure my engine is a bit cool then haveing hot then cut off, which is not good for the motor.

 

aux fan will stay on if it needs it. With turbo/diesels its important, not sure if you really need to waste the gas...

 

I do too. Itz a good idea to let the engine gradually cool down rather than just cutting it off from the heat. This is the primary function of a turbo timer and will be highly recommend with FI set up (turbines and piping gets really really hot). But I recommend it for anyone to let the engine cool down. I have mine as:

10 miles or less 1minute
10-30 miles 2minutes
30+ miles 3 minutes

I hear 30 seconds are plenty and 3minutes are really for after running the car really hard but I like to be on the safe side.

Tuner

 

I always give my cars a cool down period from 30sec to 1min. If driving a longer distance I try to go easy the last few kilomters so that the engine can cool down.

I got this habbit from driving my turbo's that could boil the oil on the bearings if the engine was switched off to quickly after driving hard(er).

 

I've spent far too many years driving any car and shutting it down almost immediately at the end of the drive. The length of driving really doesn't have anything to do with a cool-down period. It's important to get the engine and exhaust to operating temperature, not the other way around.

Turbos benefit from a cool-down period to lower their RPMs to minimal and to prevent the oil from coking inside the turbo housing (another reason to use synthetic oils). Some car provide a water circulation system for at least the turbo after shutdown to prevent temperature spikes.

If it makes you feel better, let it run a little while - won't hurt. Won't help, either.

 

[QUOTE]Originally posted by jguerdat
[B]I've spent far too many years driving any car and shutting it down almost immediately at the end of the drive.

 

[QUOTE]Originally posted by jguerdat
[B]I've spent far too many years driving any car and shutting it down almost immediately at the end of the drive.

 

I don't see how it could make any difference in a N/A vehicle but by all means do it if you want to.

 

Not many people drive full throttle into a parking spot and stop abruptly, shutting it down. And, how many places do you get right off the highway and shut it down immediatly? I think the last few seconds, or more likely minutes, that you will be driving at a lower engine speed and throttle position are MORE than satisfactory for cool down. Even so, I think the benefits of a cool down period on an N/A motor are nil. Turbos benefit from the cooldown only to prevent coking of the oil.

Even if the coolant acted as an insulator as stated above, it's not going to raise the temp of the motor in doing so and will cool down gradualy as well. After watching coolant temps very closely at the dyno in the past, I have found that even after five minutes of idleing, the coolant temp only drops a few degrees on most cars. So, I believe its a waste of time after a normal drive or even a spirited drive providing you have driven normaly for a few hundred feet to reach your parking space.