I don't have experience with OM602. What I can tell you is that Om603 will not start with 3 GP in SoCal weather. It happened to my 300SDL. However no one can tell for sure what might happen. I would always try to have all working GP if it were my car.

Btw, GP don't go out one by one. One or more can go out at the same time or very close.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.