How to know if a missing engine nut or bolt is important
When a part falls out of the engine bay or a threaded spot looks empty, it is hard to tell whether a missing nut is actually important or what specific replacement to get. Without knowing for sure, drivers are left guessing whether they need to track down a new part or if they can safely ignore it.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1asking mechanics online or inspecting similar vehicles
- 2asking for identification on online forums like Reddit
- 3guessing or relying on community responses
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Hi, is this missing nut important? If so, what kind is it so I can get the part? I have a 2014 Prius C missing this part on the engine.”source ↗
“I was fumbling in the back of the engine bay replacing the fuel pressure sensor and this fell out, hopefully it’s from something else…”source ↗
Where this came up
People with this problem also raised
- 2Why is my fresh engine losing oil with no smoke?
- 3Cracked engine head while torquing oil pressure sensor
- 41How to identify a random car part that fell off
- 2How to identify unknown debris found in engine oil pan
- 71How to figure out what an unfamiliar car engine noise is
- 3Mixed up original and replacement parts after disassembly