While in the process of replacing the gas cap on my '92 318 vert, I noticed that there are both vented and unvented gas caps available. I know the difference between the two, but was curious about which is required for a stock E30 with M42 engine. I had always assumed that vented was preferred until I discovered all the unvented versions available. Ideas?
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Vented or Unvented Gas Cap
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Pretty sure you should select non-vented.
Pressurized vapors are supposed to be vented through the expansion tank in your right rear fender, then collected in the evaporative emissions (charcoal) canister under the hood. From there, they are pulled into the throttle body through the evaporative canister purge valve.
A vented cap would defeat this.Jon (OO=[][]=OO)
1992 325ic white, stock with a 5-speed swap
Palm Beach County
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