How to find a replacement engine bolt without measuring another one
Dropping and losing an engine bolt during a repair leaves you stranded when local or official parts sites do not sell single replacement bolts individually. This stops you from finishing the repair without having to remove a matching bolt from the engine to measure it first.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Taking off another one of the bolts and measuring itDid this help you?
- 2trying to use tape to temporarily hold components in placeDid this help you?
- 3attempting to double-nut the broken stud to back it outDid this help you?
- 4drilling out and extracting the broken bolt manuallyDid this help you?
- 5Trying to drill out the broken bolt using various methods and extractor bitsDid this help you?
- 6Tightening down remaining bolts and checking if the area leaksDid this help you?
- 7Considering using a C-clamp in the area for good measureDid this help you?
- 8Looking into finding a machine shop or welder to properly fix itDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Does anyone have any godly idea as to where I can buy a singular engine valve cover bolt for the rear engine? I can't even find them on official Ford parts sites.”source ↗
“I just replaced the water pump on my 2007 Honda CRV and as I was (blindly) putting the last bolt in it slipped off the wrench and for the life of me I cannot find it.”source ↗
“My tensioner is completely loose and not connected at the second bolt near the bottom.”source ↗
“That broke off clean at the block, I've done exactly one timing belt job on a Civic and had the same thing happen.”source ↗
“The stud for the tensioner pulley snapped, and if there's enough thread left you might be able to double-nut it and back it out, but from the pic it looks flush.”source ↗
“The bolt completely snapped in the worst way on my 2012 mazda 3.”source ↗
“Myself and a handyman friend tried to drill it out using various methods without luck, and definitely damaged some of the surrounding aluminum in the process (extractor bit broke off in what little indentation was made).”source ↗
“There is a small nub of the bolt remaining underneath, but not really enough clearance to get anything in there”source ↗
Where this came up
People with this problem also raised
- 17Why am I paying for broken bolts during a car repair?
- 8Stripped engine bolt threads during installation
- 5Can I use standard bolts instead of specialty fasteners?
- 3Cracked engine head while torquing oil pressure sensor
- 12How to fix a stripped screw hole that won't hold
- 2Drill bit walking on broken exhaust stud