Timing chain slipped a tooth?

[darth_linux]

The audio in this video is not great due to the iPhones built-in compression, so it’s not sounding the same in the video as it is in real life.

Was pulling out into highway traffic today, a 50 mile an hour zone, and did my usual good, hard acceleration, and I got to about 2500 and the engine started sputtering through the carburetor, and would not rev any higher. I took my foot off the pedal, started coasting, and pulled over into a nearby parking lot and the engine would barely even run. I put the transmission in neutral and. I kept it idling with my foot on the gas, put it back in gear and had almost no power to start driving. Once I got the engine RPM above 1500 it started to make power again, but would then sputter through the carburetor.

I just barely made it to work, and I did an inspection. Seems the carburetor idle screw had loosened itself from all of the harsh treatment and sputtering. I reset the idle speed screw and it idled again, but it not sounding good. It was also smoking a bit from the PS exhaust manifold and making this strange scraping sound from the front of the engine. Check out the video and let me know what you think. Thank you.

Timing chain slipped a gear? Yes or no. 

 

[CBODY67]

Advance the distributor ONE plug wire terminal's worth. If things sound more normal, that's a timing chain issue.

Hard starting, spitbacks through the carb (with flames sometimes) are other issues, too.

IF you still have the orig chain/sprocket set in the car, consider yourself very lucky. I came to consider a timing chain change as "normal maintenance" of sorts, especially with the OEM chains tending to wear after about 80K miles from new (especially as the vehicles age, too!!!). Also considering changing such as "insurance against future issues".

Your new project . . .
Enjoy!
CBODY67

 

[darth_linux]

Advance the distributor ONE plug wire terminal's worth. If things sound more normal, that's a timing chain issue.

Hard starting, spitbacks through the carb (with flames sometimes) are other issues, too.

IF you still have the orig chain/sprocket set in the car, consider yourself very lucky. I came to consider a timing chain change as "normal maintenance" of sorts, especially with the OEM chains tending to wear after about 80K miles from new (especially as the vehicles age, too!!!). Also considering changing such as "insurance against future issues".

Your new project . . .
Enjoy!
CBODY67

Could the same thing be accomplished by just turning the distributor more advanced or something?

 

[Boydsdodge]

You may have wiped a cam lobe. To check the chain slack, remove dist cap, then while rotating engine crank by hand enough to get dist rotor to turn. Once it does go the opposite direction to see how much travel in crank till rotor turns again.
Grab a passer by to tell you when the rotor moves as you might be getting to the crank from below.

 

[CBODY67]

Could the same thing be accomplished by just turning the distributor more advanced or something?

The first sentences mention that as a diagnostic "quick fix" that could get you home. Past that, IF it worked, then your judgment past that.

When I was in college, some friends jumped into another friend's car to go to the movies. As soon as they accelerated into the street, the car started to run rough, so they made it back into the dorm parking lot. Then the guy's Dad was called. It was towed to the local Buick dealer for check-out. After the diagnostics, the timing chain set was replaced, but NOT all
of the bent valves. So he drove it to Midland and got another family car to take to school. The Buick got fixed in Midland and became a family temporary car, never seen at college again.

CBODY67

 

[Margos Dezirian]

My fist thought was fuel filter or contaminated gas.
That doesn't explain other funny noises unless it's the fuel pump pushrod or pump itself.

 

[65Port]

That engine is running way too smooth for me to suspect timing chain. I would say bad fuel, carb or craptastic chinesium ignition part gone bad (happened to me).

Let me explain- I had the exact same sputtering, no power but relatively smooth running motor. Pulled wires from the distributor cap and they were all green on the contacts. Mind you this part was less than a year old. I put my 70s era dist cap back on and it is still there.. So.. check everything including parts you may have replaced that were not necessarily bad.. My .02.. Good luck

 

[Boydsdodge]

Check if you have any bend push rods.

 

[57fury440]

I agree with what 65Port said about it running too smooth to be the timing chain. Did you check to see if the dist. came loose and moved? I would look at the ignition parts.

 

[carguy300]

I hear alot of good tips, it still seems to running on all 8, the clattering, ticking sounds like valve train issue, lifter, pushrod or rocker arm. Id pull valve covers and fire it up and watch and listen. I just did to my 440 the other day to verify mine. I feel for you though. Good luck, hope its something simple!

 

[darth_linux]

Thanks to all for the tips and support. After work today I verified the distributor was not loose and hadn't turned. I reset the idle speed. I pulled the cap to do a quick examination. There was the typical trash from 2 years of wear and tear. Nothing major. It's a heavy duty tan cap with brass connections, so no major crud, just a little bit of carbon tracing. I was hopeful that it was a misfire due to dirt, but after cleaning the cap, nothing changed. It starts up easily, idles mostly fine (sounds like it's on 7 though) but has no power under 1500 and sputters/coughs when "pressed." Above 1500 it "picks up" but if given too much throttle it will sputter. I made it the 6 miles back home, but it was slow going when starting from red lights and/or going up hills. I got her parked in the "work zone" and I'm going to do a full examination of the ignition system. It sounds, runs and drives like it has either a broken spark plug, or a bad wire. Gonna get into it Saturday morning. I'll post news when I have it!

 

[Boydsdodge]

Fuel pump push rod will be another check I would do.

 

[Grannys67]

+1 on the bad plug(s) or wire(s); also check for critter bites (squirrel, chipmunk, mouse) on the wires?

 

[Toolmanmike]

Thanks to all for the tips and support. After work today I verified the distributor was not loose and hadn't turned. I reset the idle speed. I pulled the cap to do a quick examination. There was the typical trash from 2 years of wear and tear. Nothing major. It's a heavy duty tan cap with brass connections, so no major crud, just a little bit of carbon tracing. I was hopeful that it was a misfire due to dirt, but after cleaning the cap, nothing changed. It starts up easily, idles mostly fine (sounds like it's on 7 though) but has no power under 1500 and sputters/coughs when "pressed." Above 1500 it "picks up" but if given too much throttle it will sputter. I made it the 6 miles back home, but it was slow going when starting from red lights and/or going up hills. I got her parked in the "work zone" and I'm going to do a full examination of the ignition system. It sounds, runs and drives like it has either a broken spark plug, or a bad wire. Gonna get into it Saturday morning. I'll post news when I have it!

It sounds like you may have a couple of different issues but I would check out the ticking first. It sounds like valve train. Bent pushrod, lifter not pumping up, Cam lobe going away, rocker arm broken or valve spring. If the noise is loudest on one side or another pull that valve cover like @carguy300 mentioned. If it is coming from the center, it is probably a lifter or cam lobe. Good luck.

 

[darth_linux]

+1 on the bad plug(s) or wire(s); also check for critter bites (squirrel, chipmunk, mouse) on the wires?

that's what I was thinking . . . spark plug wires are new last year with just under 1500K miles on them, so unlikely they've failed unless rodents paid me a visit over the winter. But its been running just fine until I "got on it."

 

[darth_linux]

It sounds like you may have a couple of different issues but I would check out the ticking first. It sounds like valve train. Bent pushrod, lifter not pumping up, Cam lobe going away, rocker arm broken or valve spring. If the noise is loudest on one side or another pull that valve cover like @carguy300 mentioned. If it is coming from the center, it is probably a lifter or cam lobe. Good luck.

Thanks. It's really hard to tell what sounds are what in the video because of the amount of compression an iPhone puts on the audio. It makes it sound like the engine is exploding when it's really not loud at all. There was just a "new" noise but it doesn't come through in the video very well. Thanks for the tips. If it turns out to not be ignition, I have a good list of things to '"check."