CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Odd starting noise ‘93 F250

Hi folks, I need help figuring out what I might be hearing.

When I go to start my truck, I hear what I can best describe as a knocking or skipping. Its only when I start the truck, I think the starter is going bad considering I recently fixed all wiring issues and I have a brand new battery, alternator, and connections.

Aside from the starter, what else might cause this sound? Bad spark plugs? I did have a code 172 (HEGO lean, need a new O2 sensor) could this be its doing?

If i could upload a video I did get the sound recorded.

On a side note; I fixed the last starting issue, which was the clutch master cylinder and thats been working great. And this sound is about a day old.

One other note, it only does this when cold. I was just checking my code reader ans let the engine warm up, once I went to start it again it didn’t make the noise

Key on engine off gives me an all clear, key on engine running won’t read the wide open throttle test. It also flashes the check engine light when I try (code reader causes this).

If the truck has an automatic transmission, a cracked flex plate can make a knocking noise when starting the engine.

Tester

I have a manual tranny.

After some looking, I think i may have a bad spark plug or distributor wire. If its not that when ill hand it over to a shop, pulling the engine apart is a little out of my league