First Chevy in long while... 1971 C10

[reverendxlt]

New to the forum... picked up a 1971 C10 the other day, that hadn't been started in a year or so, but was driven to the location.

250 inline 6, looks like to me... but sounds different than most motors to me, even when running well (v-8's being most of what I've had), so any starting points with this would be very appreciated.

Pretty much started right up with a charge on the battery and a little starting fluid... But there does seem to be a knock in there.

https://www.youtube.com/watch?v=SJi1ez9l_6A

Anyway, thanks in advance for any help!

[MONTE]

Nice,

What’s the plan for it?

[reverendxlt]

I picked it up as a project for my 17 year old twin sons and myself... won't be a frame up restoration, but do intend to get it back to daily service.

Any idea on that knock? Sounds like possibly a bent pushrod, but I'm not used to the thse motors.

[A1971Blazer]

Does the sound change when you push the clutch in?

[reverendxlt]

Hmm, didn't think of that, will check it this evening. Thank you.

The clutch is behaving very oddly on this truck, for sure. Only has about an inch of movement before it engages off the floor... very, very hard to use

[A1971Blazer]

Originally Posted by reverendxlt

Hmm, didn't think of that, will check it this evening. Thank you.

The clutch is behaving very oddly on this truck, for sure. Only has about an inch of movement before it engages off the floor... very, very hard to use

It seems like I can hear some lifter noise but I don't think that's what's making that particular noise...you might also take the fan belt off and start it...that will eliminate any cause from water pump...etc....it doesn't sound like rod/crank noise either

[reverendxlt]

Does seem like it's coming from the back, rather than the front... somewhere in a vague memory, I had heard someone mention this kind of thing can be flywheel or release bearing related.

I'll check after work.

[reverendxlt]

Monte... didn't realize you were in El Paso! What side of town?

[Steeveedee]

Originally Posted by reverendxlt

New to the forum... picked up a 1971 C10 the other day, that hadn't been started in a year or so, but was driven to the location.

250 inline 6, looks like to me... but sounds different than most motors to me, even when running well (v-8's being most of what I've had), so any starting points with this would be very appreciated.

Pretty much started right up with a charge on the battery and a little starting fluid... But there does seem to be a knock in there.

https://www.youtube.com/watch?v=SJi1ez9l_6A

Anyway, thanks in advance for any help!

Sounds like valve lash to me. Maybe pop the valve cover off and look for loose rocker arms.

Usually as a clutch wears, the pedal engagement height changes. It at least need adjusting.

[MONTE]

Westside

[reverendxlt]

Yeah, it feels kind of like it's at the end of it's adjustment, to me. But I'll check it out for sure.

Needs a new valve cover gasket anyway, so I'll check that too.

['68OrangeSunshine]

Change the oil and then listen again. L6s tend to tick more than V8s normally. Use a good straight viscosity oil. Valvoline VR1 SAE 30 or 40. Any clue as to engine miles elapsed?
A valve adjust could not hurt. Tom Lowe has a good video on L6 valve adjustment, done cold 1-5-3-6-2-4, by rotating the crank 1/3 at a time. See www.12Bolt.com tech tips.
Have you pulled a compression check?

[reverendxlt]

Oil change is on the menu today too... thanks for the info. I was a little surprised at the different timbre of the the thing

I honestly don't know about mileage... odo. reads about 38k... whether that is 138, 238, 338... anybody's guess. PO had it since 1989, and it doesn't sound like he really put a ton of miles on it.

['68OrangeSunshine]

Originally Posted by reverendxlt

Oil change is on the menu today too... thanks for the info. I was a little surprised at the different timbre of the the thing

I honestly don't know about mileage... odo. reads about 38k... whether that is 138, 238, 338... anybody's guess. PO had it since 1989, and it doesn't sound like he really put a ton of miles on it.

I know how that is. I guess GM didn't make a 6th digit odometer in the hope that you'd trade in for a newer, nicer truck, long before 99,999.9 miles.
Go for the middle number for an arbitrary guess. My rule is the more mileage, the thicker the oil. Try the 40 weight. I'm in Tucson, you're in Texas -- we're about the same climate and latitude.
The L6 has a sweet sound, especially with headers, if it's done right. While V8s may growl like bears, L6s can snarl like mountain cats.

OBTW, Welcome aboard.