Quote Originally Posted by b17a1db2
I always run it. I did a B18C swap to my CR-X, was bummed out cause it wouldn't start... hmmmmm. what could it be.... So I took a last look at my engine bay to make sure everything was hooked up... Seemed all fine, then I noticed I didn't have that valve cover ground to the chassis..... figured I might as well put it on.. I did, and gave the motor one last try to crank up... IT DID!!!! And yes, I had all my other engine/transmission grounds hooked up.
Exactly, if the engine is not properly grounded there may not be enough current to turn the starter over.

Technically the valve cover should be insulated and grounded to help prevent radio interference aka High-frequency electromagnetic interference (EMI).

As for engine grounds, if it's not properly grounded the coolant will become charged and electrolysis will eventually burn holes in the radiator & engine. Oops. lol!

BMW engine at the thermostat...


There have been cases of wheel bearing getting destroyed, transmissions leaking, and throttle cables frying all because of bad engine grounds. If there is not a direct route for the power to get to the chassis then it will find a way or try it's best. Have to be careful with properly grounding BMW engines or the power may travel up through the engine harness and destroy the DME/ECU. Crazy shit.