Changing glow plugs hot or cold engine?

[Tony x]

Hello all.
Is it best to remove the old glow plugs with the engine hot or cold.
I ask because I hear they can shear off.

Also, If they do shear off, is it a major job to sort out?

Thanks

[helen&tony]

Hi
Do them cold...with a LONG DEEP socket.
Shearing...well, it can be a problem, but not always insurmountable. Just take care. apply a wee bit of "Copaslip" to the threads of the new plug, and torque it carefully.
Cheers
Helen

[mikexgough]

I've changed them "Hot" & Cold on various engines, hot due to circumstances though. Preference for me is cold and as Helen says.... use a deep socket and go gentle undoing them.

Generally they a 12mm deep socket will do and big +1 for using copper grease for reinstall...on copper grease..beware of the Halfords rip off price just for a small tube...

[Tony x]

Thanks for your help - they came out cold and new ones went in with copperslip.

[lazyb5]

17nm rings a bell as the torque setting which was loads more than I would have done

[Diplomat]

Re copperslip, someone once told me that using grease is not recommended because the high compression in a diesel engine can make the grease explode, damaging the threads.

Sounds a bit of a worst case scenario but there might be some logic in it.


Frank