Head aches.............

[muncher]

Ive been woundering about these head probs mentioned on this forum. As far as i know a motor fitted with a turbo should not be switched off immediately. It should be left to idle for a set time say 20 secs. If you switch off straight away, especially after a high speed run, you could put undue pressure on the head/gasket eventually causing it to fail. I don't think this applies to the intercooled versions though.
Just my opinion.....................mu ncher

[Guest]

Ive been woundering about these head probs mentioned on this forum. As far as i know a motor fitted with a turbo should not be switched off immediately. It should be left to idle for a set time say 20 secs. If you switch off straight away, especially after a high speed run, you could put undue pressure on the head/gasket eventually causing it to fail. I don't think this applies to the intercooled versions though.
Just my opinion.....................mu ncher

It's not so much the undue pressure on the head gasket although if the turbo gets too hot and can't cool down it may cause one side of the head to be hotter than the other, the main reason for letting the engine idle for a few seconds is to keep the oil circulating through the turbo thus allowing it to cool. If you don't do that the main problem will be failure of the turbo bearings. This is the same on all turbo cars, petrol or diesel, not just the Surf. It is also why you should not rev the engine immediately until the engine has idled for a bit to get the oil circulating properly and you also shouldn't really rev it too much until the oil has warmed sufficiently to get good efficient circulation around the turbo - this is less of a problem when using low viscosity oil. It is also good to use oil designed for Turbo engines because it will break down less at the seriously high temperatures that the turbo runs at.

Cheers

[Morr]

Ive been woundering about these head probs mentioned on this forum. As far as i know a motor fitted with a turbo should not be switched off immediately. It should be left to idle for a set time say 20 secs. If you switch off straight away, especially after a high speed run, you could put undue pressure on the head/gasket eventually causing it to fail. I don't think this applies to the intercooled versions though.
Just my opinion.....................mu ncher

Allowing a turbo motor to idle before switching off is really aimed at protecting the Turbo more than the head/Gasket. It allows the turbo to spin down gently, without sudden loss of oil pressure. If the engine is turned off when the turbo is v hot the heat can cause the oil in the galleys to burn and coke up the pipes leading to future oil starvation and subsequent turbo bearing failure. The turbo in the Surf is water cooled so this should not strictly be neccessary, some fit turbo timers to help this but most opt to simply drive easy for the last mile or so of their journey, therby allowing the turbo to cool somewhat after a long run. A few seconds extra spend idling before switch off certainly can't hurt either tho.



Edit *** Beaten to the post by Andy

[muncher]

Yeh i always let it idle a few secs, by the time i've done all my fiddling (that sounds a bit pervey!) I mean radio off windows up etc, should of been long enough. I have heard about turbo timers and often woundered what that meant. I didn't know the turbo is water cooled though, learnt something new.....muncher

[Guest]

Yeh i always let it idle a few secs, by the time i've done all my fiddling (that sounds a bit pervey!) I mean radio off windows up etc, should of been long enough. I have heard about turbo timers and often woundered what that meant. I didn't know the turbo is water cooled though, learnt something new.....muncher

Yep 2 water pipes come at it across the front of the engine on the 2.4.

Switching off early also stops the water circulating so again the water cooling is not working as well. The oil circulating through the turbo does a considerable amount of the cooling as well as lubricating.

Turbo timers just keep the engine running for a while even after you have switched off the engine. Main downsides with them is that it is illegal in this country to leave a car unattended that is still running so strictly speaking you should stay with the car until it has stopped running. Also some alarm systems can't cope with them so you need to stay in the car until the turbo timer shuts off as you can't get out and lock it if you have an alarm. Because of this you might as well just sit in the car and switch it off manually.

Cheers

[muncher]

I recently got back from a trip to NZ. In one place i stayed a 4x4 pulled up outside bl**dy masive it was. The bloke got out and walked off motor still running i guess that was fitted with a timer.