There is something wrong with my turbo!! :(

When I switch the ignition off I can physically hear my turbo still spinning for a good 10 seconds.

There is something wrong with my EGT gauge as well because the temperature starts to drop immediately when I come to a stand still/or idling. I really must get all these problems fixed.

Dont you mean the electric radiator fans that usually keep running after you turn off you engine? It's pretty impossible for the turbo to spin after the engine stops.

Dont you mean the electric radiator fans that usually keep running after you turn off you engine? It's pretty impossible for the turbo to spin after the engine stops.

I'm cheating a bit as the turbo in question has a load of ball bearings in it helping it along.

Who do you think you are "Jack Hargreaves or Fred Dinnage".......:P

Younger members may not get this..

Unless they live out of town

Ok so for example' date=' you have just been out on a good run and your turbo housing was about 700 degrees c, maybe hotter, i dont think that 30 seconds or even 2 minutes is going to cool a turbo by very much when its covered by a heat shield in a warm engine bay!

I would be more worried about the heat soak in your block and head from the lack of coolant flow causing horrible heat spots and what not.[/quote']

while you are right about metal piece not cooling down in 30 sec, however the rate of heat dissipation is directly proportinal to the temp difference between the hot part and the ambient surroundings. So althought the turbo wont cool down to 35 degree C from 700 C in 30 sec, it will however cool down to 500 C in a min or so.( obviously all temp we are taking are hypothetical temp, I dont know how hot the turbo can really get). Now if the oil cokes at 650 C ( again I dont know the temp at which oil loses it's lubricating properties), and u shut off the engine while the turbo is at 700 C then we have loss of lubricating properties, whereas cooling it down to 500 C the oil is not coked.

also don't forget that engine oil acts both as a coolant as well as lubricant. It removes heat from the engine while lubricating it. If the engine is on and oil is being circulated by the oil pump then it is also removing heat from the engine.

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:confused: ..

Guessing a response was expected?

Either way - if you drive the car 'hard' it's definitely worth idling it a bit before shutting off. Not sure how this competes with the 'not enough oil going round at idle revs' thing but who knows LOL

Personally I try to ease off a bit around the endpoints of my journey. Near my work it fits as there is a 20mph speed limit for about 500 yards-ish followed by a parking garage that is steep so to avoid scraping the spoiler I need to virtually crawl the last bit. Near home I don't strictly need to go that slowly, but at 30 mph speed limit + school nearby + kids playing I don't get near 30 mph in the last street or two, so in reality it's hardly ever a problem