Blue cold dash engine light

[Newbie GT]

Hi guys after the blue engine light goes off in dash is it safe to give a rev if someone wants to hear exhaust note?

Does it mean oil and water temp ok ?

[owen]

Water temp yes.

Oil temp no.

[Newbie GT]

Water temp yes.

Oil temp no.

Cheers Owen so if I was looking at temp gauge and was under half way and car had been sitting for about three hours and I revved it a few times to about 5k is that classed as a cold engine ?

[Surge]

I wouldn't rev too much in your case, at least not until you figure out that knock you are hearing.

Or rev as much as you want but put cash aside for an ej257.

[Manaz]

Water temp yes.

Oil temp no.

Cheers Owen so if I was looking at temp gauge and was under half way and car had been sitting for about three hours and I revved it a few times to about 5k is that classed as a cold engine ?

Once the temperature gauge starts moving, the coolant temperature is rising - that's done in modern engines by basically not circulating coolant when the engine is cold.

Oil doesn't take long to coat surfaces, generally once the coolant temperature is climbing, you should have decent lubrication occurring. Lubrication is more important than coolant temperature.

[owen]

Just because it's lubricating doesn't mean it's at optimal operating temp & viscosity. Especially not at 5000rpm.

[Newbie GT]

Just because it's lubricating doesn't mean it's at optimal operating temp & viscosity. Especially not at 5000rpm.

Therefore damage can be done ?

[Newbie GT]

owen wrote:
Water temp yes.

Oil temp no.


Cheers Owen so if I was looking at temp gauge and was under half way and car had been sitting for about three hours and I revved it a few times to about 5k is that classed as a cold engine ?

[Manaz]

Just because it's lubricating doesn't mean it's at optimal operating temp & viscosity. Especially not at 5000rpm.

Modern oils are pretty damned good at this - and I was surprised just how warm the oil can be after 3 hours. Of course, it's not something you'd rely on day in and day out - but a one-off burst up to 5k rpm won't kill the engine because of a lack of lubrication.

This is particularly true given that the ECU won't engage S# mode until the blue light goes off - so Subaru themselves seem to be of the opinion that once the blue light is off, the engine is ready for whatever you want to throw at it.

[dja]

The blue light goes off when coolant reaches 70degrees.
Modern oils get up to operating temp pretty quick, and are forced into the galleries from startup.
So there will always be lubrication, however film strength is not at 100% yet
a free rev with no load will not hurt you.

[Deep Heat]

Doing it once is unlikely to do any damage, I wouldn't get into a habit of doing it unless you don't mind blowing engines.