Turbo Cooling Down Thingy

pistonbroke · Post by **pistonbroke** » Wed Nov 29, 2006 6:45 pm

Never having owned a diesel vehicle before, the manual tells me to run the ending at idling speed for 1-2 minutes (depending on type of driving) at the end of each journey to cool the turbo down. Does everyone else do this? Is it necessary? Is there anything like an automatic engine switch-off gadget in the same way as you can get remote engine starting? Or, perhaps, some sort of motor that would automatically run just the turbo for a couple of minutes. Feel a bit of a melon sitting there on tick over. Could be boiling an egg or something.

Bumbly1 · Post by **Bumbly1** » Wed Nov 29, 2006 7:17 pm

Some of the Bongos imported have a turbo delay timer but this is removed for SVA, I dont think it is legal to leave an unattended vehicle on a public road with the engine running. They are available for retro fit though.

Tom

pistonbroke · Post by **pistonbroke** » Wed Nov 29, 2006 7:20 pm

Thanks Bumbly. Any idea where from/cost etc?

Bumbly1 · Post by **Bumbly1** » Wed Nov 29, 2006 7:30 pm

Demon Tweaks may sell them, I think they are called a turbo timer, might be worth a Google. That said, I dont bother about the cooling period usually, I think it is mainly referring to prolonged turbo use, ie motorway, pottering round town the turbo does not work for such long periods and therefore may not heat up as much. Dandy will be along to put me right soon I'm sure

Tom

Veg_Ian · Post by **Veg_Ian** » Wed Nov 29, 2006 8:39 pm

The recommendation for allowing the turbo to cool is really aimed at petrol engines which run a lot faster and hotter than a diesel turbo. Unless the engine has been running really fast on say a fast motorway run or long hill climb in low gear/high revs then yes let it cool by letting the engine idle for a couple of minutes. That allows the oil to circulate, turbo to run down and cool off a bit before switching off. Again not essential for a diesel but not a bad habit to get into.

dandywarhol · Post by **dandywarhol** » Thu Nov 30, 2006 1:09 am

I would disagree Ian - the turbo speed is related to exhaust gas speed, not engine speed so a high compression (twice the compression ratio) diesel will spin a turbo equally as fast as a petrol engine...............

Veg_Ian · Post by **Veg_Ian** » Thu Nov 30, 2006 9:35 am

Dandy - true about the exhaust gas speed but it is a consequence of engine speed or rather revs. I still maintain though that a diesel turbo doesn't get that hot as to worry too much about leaving it to cool except under extreme conditions. However, I'm more au fait with Toyota diesel turbos which are water cooled and made the assumption that the Bongo turbo is water cooled. Is it? I should have checked first I suppose.

David Edwards · Post by **David Edwards** » Thu Nov 30, 2006 10:11 pm

I have always waited a minute or two before switching off on short journeys but.. if you have driven for some distance at higher than normal driving speeds then dropped to say 30 or 40 local limit for a while towards the end of the journey this is normally enough for the turbo to cool down and switching off should not be a problem. This is the way I do it and having had me bongo for about three years now with no probs I must be doing it right. Happy motoring.

dandywarhol · Post by **dandywarhol** » Thu Nov 30, 2006 10:17 pm

I agree with that David........the only real time you would need to let the engine idle for a bit would be coming off motorways and into service stations just off the motorway exit ramp.