Ignition Control Module

[bullsta]

Hi all.
My ICM (Bosch part 0227100211) has carked it on my GTI.
Apparently quite common with our car.
Big thanks to Gav for diagnosing over the phone whilst I was broken down!!
Question I have is regarding heat paste.
There is a metal plate attached to back of ICM and another plate attached to outside of air box.
What paste do I buy (Autobarn etc) and do I need to remove plate off ICM and apply paste to unit, replace plate and paste that as well as paste the external plate on airbox.
Hope this makes sense?
Any help appreciated.

[Sirocco20348]

I used the same paste for when I put the heatsink on my computer CPU.

I used Arctic Silver thermal paste, but you can use any thermal paste purchased from the local computer store.

You only need to apply in between the ICM and the Airbox metal mount.

Just be careful how much you put on. As pressure is applied it spreads well. Start with a match head amount and go from there.

[bullsta]

Thanks Sirocco. What exactly does the paste do?
And am I better off with too much rather than too little?

[Sirocco20348]

Hypothetically, If you get out a microscope and inspect the surfaces of both the ICM and the metal plate on the Airbox, they are not perfectly flat. These uneven surfaces prevent optimal heat exchange.

The paste is designed to be a filler between the two surfaces, allowing the heat to be dissipated efficiently and effectively.

You only need the smallest amount of thermal paste between the two surfaces, because it's purpose is to fill the microscopic pits and falls on the metal surfaces.

Too much paste will have a negative impact on the transfer of heat and start to insulate it. Eventually the part will overheat and fail.

Start with the tiniest amount, match head or smaller. And see how you go!