Hello all from the U.S.

I went and test drove a WRX about a week ago. I intend to buy one next spring.

The salesperson kept stressing to me that you absolutely HAD to let the car idle for 90 seconds to let the turbo cool down. I've not seen this anywhere else or heard it from anyone either. Is this true? If so why? I've driven other turbos and never had to do this and the whole idea seems a little odd to me. The turbo itself doesn't seem like it would get that hot (except for the heat from the exhaust gasses) and I wouldn't think that idleing for 90 seconds would really do much in the way of cooling it off.

 

The turbo gets very hot indeed after a blast. There is a sticker on the door which tells you to idle for one minute after a heavy blast. The reason for this is that oil pump stops when engine turned off so oil left in the turbo can cook and turn solid. Idling for one minute allows the oil to circulate through the turbo and cool it just a bit. I find the best approach is the drive with minimal or no boost for the last mile or so - which is usually in a 30 limit anyway so not a problem. Also note when pulling off from a high speed road to fill up with petrol if you have been driving under heavy boost conditions - i.e. 85mph+.

 

If you turn your engine off while the turbo is spinning there is no cooling oil being pumped through the system. Therefore the oil that is in the Turbo just gets hotter and can cause problems by melting the components of the turbo or destroying the bearings or something. Not good and v expensive to replace.

You can buy turbo timers that run your engine from 60 sec to 3 mins.

Cheers

Neal

 

The turbo timer sounds like a good idea to me. I often wouldn't have time to wait for a full minute or 90 seconds to idle. How exactly do these work and are they pull the key and walk away affairs?

 

Yes, you can lock the car and leave running, but check insurance and the law out first. I don't think they like you leaving a car running unattended.

You can also get turbo timers with car security now. Its just a timer curcuit in the alarm/add on.

Iain.