Get repair help from Gemini on an old Mitsubishi Triton and catch three wrong instructions

Posted

Aug 11, 2026 by smackeyacky (Hacker News)

·

Last checked

Oct 17, 2026

·

Method:

How we verify

Evidence: Described by posterThe person describes what happened in words, without screenshots or video.

Outcome

While replacing the balance shaft chain guides on an old Mitsubishi Triton, Hacker News user smackeyacky asked Gemini for help. It suggested removing the balance shaft chain as an emergency fix, though the chain also drives the oil pump; it suggested clearing water-contaminated oil by filling the crankcase with hot soapy water and running the engine; and its instructions for fitting the new gears left the chain guides misaligned. The poster ignored those steps and did it their own way.

Agent

Gemini

The source didn't share its exact prompt, so we wrote this from what it describes.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Talk me through an engine repair on my car, step by step, without guessing.

What I can give you (ask for whatever's missing):
- Make, model, year and engine code
- The part I'm replacing and why
- Tools and experience I have
- Whether I have the factory service manual

Safety first: anything touching brakes, steering, airbags, fuel lines or lifting the car is a job for a qualified mechanic unless I confirm I have the tools and experience. Say so clearly.

Rules:
- Base each step on the service manual for my exact engine and say when you aren't sure.
- Before suggesting anything is removed or skipped, check what else it drives or protects.
- Never suggest putting anything in the engine that isn't the specified oil or fluid.
- Give torque specs and alignment marks only if you can point to the source; otherwise tell me to check the manual.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.

Output: A numbered step list with the manual section for each step and clear warnings.

You'll know it worked when: I finish the job without damage, and every step matched the manual.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Talk me through an engine repair on my car, step by step, without guessing.

What I can give you (ask for whatever's missing):
- Make, model, year and engine code
- The part I'm replacing and why
- Tools and experience I have
- Whether I have the factory service manual

Safety first: anything touching brakes, steering, airbags, fuel lines or lifting the car is a job for a qualified mechanic unless I confirm I have the tools and experience. Say so clearly.

Rules:
- Base each step on the service manual for my exact engine and say when you aren't sure.
- Before suggesting anything is removed or skipped, check what else it drives or protects.
- Never suggest putting anything in the engine that isn't the specified oil or fluid.
- Give torque specs and alignment marks only if you can point to the source; otherwise tell me to check the manual.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.

Output: A numbered step list with the manual section for each step and clear warnings.

You'll know it worked when: I finish the job without damage, and every step matched the manual.

Before you finish: re-read my goal and constraints, check your answer against each one, and list anything you assumed or couldn't confirm.

Source

https://news.ycombinator.com/item?id=49253269