Just came into my head this morning and thought it'd be a good idea to post it on here. Couple of things I learnt from my time at Holset.

 

1) The majority of damage to the bearings and shaft of a turbo occurs within the first few seconds of cold start. We all know that if we leave the zed standing for a week we get the tatatatatat from the hydraulic lifters. In the same way every time you turn off your engine oil drains away from the bearing housing of the turbocharger and the oil feed. If you have left your car standing for a while and even if you have not, its a good idea to crank your engine for a few seconds before starting it. This builds oil pressure and ensures oil gets to the dry bearings much faster than if you start up immediately. A lot of truck engines we made turbos for would have this electronically built in (the engine would fire up after a set amount of time eg 4 secs).

 

2) Another thing on bearings, never rev you engine then turn it off, yes I have seen it done, it may sound or look cool but your tubs will hate you!

 

3) The majority of damage to the oil seals occurs in the first few minutes after a hot shutdown. Hot shutdown meaning turning your engine off a very short time after running it with a high load. At full load conditions your turbine housing sees temperatures of ~600 deg C, this heat radiates from the housing and is also conducted down the shaft to the bearings and the rest of the turbo. The oil as well as lubricating the the turbo also helps to cool it, if you have a water cooled bearing housing then its even better (I don't know if our cars do). But in a hot shutdown situation the heat gets conducted back from the turbine to the stagnant oil in the bearing housing which begins to break down at ~130 deg C, if the oil gets over 150 deg C it breaks down completely. The oil cokes up the bearings so the clearances get all messed up, the black residue scores the bearings and the shaft. The oil around the seals cokes up the seals and they will soon become useless. If you want a turbo timer then get one, but you only need to let your engine idle for 1-2 mins before shutting it down to avoid this.

 

HTH

Yaseen

Turbo timers will help vastly won't they?

Turbo timers will help vastly won't they?

Yes, they will, but i don't see the point in spending ~£100 on something that I can do for free. Just take it nice and slow for the last minutes or two of your journey, and if you can let your engine idle for a minute or two when you park up. Just leave it on while you take the face off you head unit, and get your wallet/sunglasses/whatever. Personal preference I suppose.

taking it steady for the first and last few imns is good for most of the car not just turbos... gives the temps of everything chance to stabilise.. especailly brakes.. so easy to thrash it stand on brakes walk away and leave the heat in the pads to warp your discs!!!"!!! I agree about why owna turbo timer.. just take it steady to be honest... but I guess if your lacking control then TT the way forward...

If I'm driving it hard, I think ahead and take the last 5 mins off boost anmd drive very gently, let it idle for 20 seconds and switch off.

I dont think my neighbours like it when i leave it running at idle for 2 mins. I know it sounds crazy but my house is a clock of 4 type thing and I park 4 meters away from my living room window. The car is loud as fook and it goes right through the building with its wonderful low barble sound. :rant:

 

I agree it is always a good thing to do and for the space of a few mins each time you aint gonna miss much. :D

 

Dave G

I always leave my timer for at least 30 secs, even on short journeys. 5 mins if I have been spanking the b1tch...lol

i think running it at idle isnt as effective as driving the car gently for the last few mins of the journey.. its nice to run it at idle but it also means the other fluids dont get chance to cool... so taking it steady for the last bit on the way home is good and doesnt pi$$ off the neighbours..

good sound advice.. i am a idiot...

i must be and wont be anymore.. ie giving it a quick rev before shutting it off... however i kinda equaled it out.. by starting the car and leaving it running a few minutes before setting off.... it helps get the temp warm in the car in the winter you know ....lol.. and i even do it in the summer...

you should drive of as soon as you start the engine - but gently. This way the engine gets hotter quicker, minimizing the amount of cold-running which entrains water and acidic gases (stresses oil more) and increases wear.

 

I take it easy for the first few miles, before ever giving more than, say 3,000 rpm - this is in my 200SX. I would only ever boot the car after 5-10 miles when car has fully warmed-up.

fook me nelson where you been hiding????

 

you out on tag then? :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:

when fitting new turbos or after an engine rebuild you always remove the fuel pump fuse at the front of the driverside engine bay,obviously all your doing is cranking the engine no fuel flow

 

all that is happening is oil is getting around the turbos engine etc,so in theory if you havnt started the car for awhile it would make sense to do this for 15-20 secs if your battery is in good condition that way oil is in all the places it should be from cold startup

 

obviously yaseen has said the same thing,except removing the fuel pump fuse stops the engine from fireing!

 

greg

and yes the stock turbos have water feeds to cool the housings down,although some people dont bother on some aftermarket turbo applications to prevent leaks etc,and as a water leak from a turbo can be hard to find/diagnose,some owners blank the feeds off,less pipework and all that is needed is a bypass of the originals.

I just drive like a big wuss and never bring my turbos on boost.