New ETM problems on older throttle bodies

[precopster]

As you can see in the photos the commutator (magnet) is chafing against the internal armature and stopping the throttle from returning.

I've seen this now in 3 ETMs that have been sent to me. The solution is to file down the aluminium magnet cover until it clears and spray the aramature with new laquer. The example in the photo had only 0.6mm clearance for both sides (only 0.3mm on each) which is not enough.

It's far better to discard this ETM body and use another by swapping the board over, then use a non-contacting Sacer while doing reassembly but this repair is not for the faint hearted.

[precopster]

The rabbit hole goes deeper: thermal paste was applied sporadically by Magnetti Marelli

The photos below show an ETM with plentiful thermal paste which was built in 2000 and the board is still running. The other photo shows only a dab of paste in one area and is from an '03 build ETM that had a faulty board.

I only hope that the newer ETMs all have plenty of thermal paste to help the ETM body act as a heatsink.