Hi all,

WRX STi Spec D 07/07.

Need I start my car in the mornings and leave it running before I drive it?

I tend to leave it running for I guess 3-4 minutes on average, and then drive it, but am I doing more harm than good?

I'm not in the least bit concerned about emissions....given the price of my road tax, but am I doing any harm to my engine?

I know oil gets around the engine in seconds, but I have heard stories of "glazing" the bores? Whatever that means?

Just curious as in winter time (rather than this time of year) would / should I run it then for a bit before driving it?

What would have been meant by glazing?

Matty

 

you dont need to warm it up , just drive it but dont boost or rev it high until its warmed up properly which isnt when the water is upto temp its when the oil is upto temp which is probably 3 or 4 minutes after the water.

glazed bores is something totally different afaik, its when the cross hatchings (scratches in the bores) have worn away so the bores are smooth, this is bad because oil gets trapped in the cross hatches and lubricates the piston rings

 

Got ya, thank you very much.

 

Just keep the revs low and smooth and Stedee said off the boost, Can do the same after a long drive, like motorways where you will be at higher revs, allows Oil to flow through the turbo to keep it cool and lubed after turned off.

 

+1

Due to my location it takes time to reach normal flowing traffic. I change at low revs until warm, and make sure I don't use boost on my slow way home, no need for a turbo timer.

 

Do turbo timers reallly work??? Say you have had a huge blast, fans running like mad as the engine is hot hot hot... you turn the engine off but it's stationary and continues to run, does an engine on tick over not get hotter and hotter as aposed to a car with wind in its hair?

 

Often wondered this myself.

 

Utter, utter waste of money - The End
As for warming up - if you leave it ticking over to warm up you are doing more harm than good as it takes way longer for the engine to reach temperature.

 

As has been said. I simple get in car, start it and drive.

All you need to remember is unless you have an oil temp gauge oil takes longer than water to come up to temp.

Keep off boost , keep the revs below 3,000 rpm until the temps have been reached etc.

 

I've had many performance cars and always give them a minute or so on the drive before driving off. Then take my time for a good few miles, it's quite surprising how long it takes to get the oil up to temp.
As for cooling down, just drive the last couple of miles off boost ad it'll be fine.

 

its the turbo you are trying to cool down by letting it idle for a bit, they can get very very hot. afaik the reason you want it to to cool down is that the oil sticks to the hot parts in the turbo and dries, this can eventually block the oil galleries in the turbo.

 

I found without warming up for a few mins, if i drove it straight away it always wanted to cut out when coming to a stop at say traffic lights and T-junctions and the like so always had to blip the throttle to stop it from conking out. But if i warmed it up for say 2-3 mins with it ticking over, then it was fine I was told it was down to the Link g3 ecu? Never did solve why it did that and why it was always slow starting even with a optima battery but was told it was a trait of the Links and Gems ecu's.

 

The turbo on an Impreza is water cooled and because of the location of the header tank and the natural convection of water - the turbo will continued to be cooled after switch off.

 

Do you mean via the intercooler and I/C waterspray button?