New Engine Noise

[TheDude]

Worst thought is timing chain guides - tensioner [SIZE=15.4px]shenanigans[/SIZE]?

Also Inside that front blue block, just behind your watery impeller, is also the lobe for actuating the fuel pump -- is it fuel pump actuator slap back onto the front lobe.. ....has one recently fitted a cheap and cheerful aftermarket fuel pump (c'mon fess up :classic_wink: ) ? or is it 50 years old in which case one of the return springs no longer has tension and the actuator is slapping around?

Just for information sake... the actuator on the original fuel pumps have spring tension in both directions of the actuator arm... the weezly cheap aftermarket tin-pot one's have only tension back to the lobe - causing slap...the designers, of course, having the IQ of a chair leg and the intellect of a bicycle.  :classic_dry:

I'm starting to think the same thing about the timing chain. Using an electric fuel pump with fuel pump hole blocked off. Thanks!

Really hard to tell where it's coming from. Check that your distributor cap is fully seated and square on the distributor, as the rotor could be hitting the terminals - and that all the wires are fully engaged.  If it's definitely from the front of the engine, I might lean towards something being up with the timing chain, maybe the cam bolt is backing out. 

Thanks, I did check the distributor and everything looks good to me. Thinking the same thing about the timing chain. Hate to rip all that apart just to try and figure out what's up, but it's looking like that's where I'm heading. 

 

[boilermaster]

Dude,

After listening to your videos, I am convinced your noise is at camshaft speed or 1/2 of crank speed.

So you checked the distributor cap, but what about the advance weights or a screw coming loose from inside the distributor ?

The other would be the fuel pump eccentric and or cam gear retainer bolt has come loose.

You have a fuel pump block off plate, I suggest you remove it and take a peek inside, even if it means doing so with a probe type camera.

If by eye you MAY be able to see in there with a pen light, might want to remove your ps pump, and the oil filter may still be in the way.

if you get a peek, I suggest you NOT pry against the cam gear, as you could lose it all together if the cam bolt is backed out.

If the cam bolt has backed out, the fuel pump eccentric WILL also be loose, that is where you need to look, fuel pump gasket is pretty cheap to replace.

Boilermaster

 

[TheDude]

Thanks for the feedback. Good point about the distributor, I looked at the top side, but didn't dig down under the electronics to see if anything is out of sorts. It's a Mallory UniLite and I can't figure out how to get under the electronics short of pulling the distributor and completely disassembling it and basically rebuilding it. That said, I did poke at it with a stethoscope and get my ear right up on it and didn't get anything at all from it.

I wasn't able to get myself in a position to look up in the fuel pump opening, so actually just installed a mechanical pump in there again to see if anything changes. No difference. Well as I mentioned the sound comes and goes and at first it was silent so thought I had something. Shut if off for a minute and turned it back on and it made the noise again. Literally different every time. Loud, then totally silent the next or starts with some noise then sort of goes away. 

Anyway, it really does sound like right at the front of the engine, so I think I need to go spelunking and see what happens. After working on the thing for months (or years?), I was really just trying to avoid taking things apart again.  Wish I had a mechanic I could hand this off to, but no such luck at the moment. 

Thanks for the time trying to figure this out. 

 

[Tnfastbk]

Did you check the fan/fans touching the radiator?

 

[TheDude]

Thanks. It's electric fans and this happens regardless of them being off or on. 

 

[c9zx]

OK, long shot number two. I don't know if you have headers or exhaust manifolds, either way look for a small hole in a header tube, leak at flange or crack in manifold. Chuck

 

[TheDude]

Interesting idea. Something like that had occurred to me. On that same drive I hit a pretty gnarly pot hole so in the back of my mind I keep thinking that something broke and what I'm hearing could be outside the engine. Like a motor mount rubbing metal or something like that. I haven't looked closely at the exhaust though. Not sure how well I'm going to be able to see anything on that rusty header, but I'll give that a look and see if that gets me anywhere. 

Along those lines, had a couple neighbors pontificating on this and they came up with two solutions. 1st, get a louder stereo and 2nd run it with open headers.  :classic_unsure:

I'll poke around out there this evening. Thanks for the idea. 

 

[boilermaster]

Dude, both the tiny exhaust leak and motor mount sound like possibilities.

Any chance you could secure your phone in the engine bay to take a recording while letting the clutch out while in gear and listen to your recording and compare to the previous ??

Safety first !!!

 

[TheDude]

Dude, both the tiny exhaust leak and motor mount sound like possibilities.

Any chance you could secure your phone in the engine bay to take a recording while letting the clutch out while in gear and listen to your recording and compare to the previous ??

Safety first !!!

So I had my wife stand in front of the car while I dumped the clutch and noise doesn't change (the engine I mean  :classic_smile: ). And just kidding, she's awesome and the noise when it's happening is usually loud enough to hear from inside the car. Naturally this time it wasn't making the noise at all so wasn't able to test. Usually if I shut it off then start it back up in a little bit it will make the noise again. It's too late out here to do that much without pissing off the neighbors so I'll have to do that tomorrow. 

Can't get much a look at the header from up top, so might have to put it up in the air to get a look from underneath. 

 

[Kilgon]

Even though it sounds more in the valve train it could be a rod bearing.  Try loosing the plug wires at the distributor so you can pull them out easily.  Start the engine and using a pair of pliers pull one at a time and see if the knocking goes away or quiets down a lot.  If so then more than likely you have a rod bearing going out. 

 

[Kilgon]

Even though it sounds more in the valve train it could be a rod bearing.  Try loosing the plug wires at the distributor so you can pull them out easily.  Start the engine and using a pair of pliers pull one at a time and see if the knocking goes away or quiets down a lot.  If so then more than likely you have a rod bearing going out. 

Don't want to get you worried and more than likely it isn't a rod bearing but I would still pull one wire at a time and see if the noise changes.  If so then at least you know what cylinder it is coming from  and can proceed from there as far  as what is causing it.  If no difference then it's one more thing you can cross off the list.  If no change then it might be time to pull the timing chain cover and  see what you can find there.

 

[TheDude]

Thanks. This has been in the back of my mind since the beginning as my google searches for short blocks would bear out. I'll be trying the plug thing hopefully later today. While it's not a great time for me to rebuild or replace an engine, I need to get it figured out one way or another. 

Thanks again for the ideas and regardless of the results, it's more info than I have right now. 

 

[Don C]

Yes, good idea to get it figured out before something lets loose and you need a new block, oil pan, etc.

One thing you might do is to pull off the oil filter and dissect it, see if there is any metal in it, use a magnet to check for steel or iron particles.

 

[TheDude]

Well yesterday it wouldn't make the sound. Today it's louder than it's ever been and louder in person than the video sounds. At some points it sounds like marbles floating around under the valve cover. 

https://photos.app.goo.gl/G5Yj9agWH4Ry1SCs9

It definitely changes when you pull the wire on #5 (front most on the driver side. Doesn't go away like the videos I've seen of testing rod bearings, but does cut down that loud snapping or clanking sound. 

 

[Hemikiller]

The way it changes with the #5 wire pulled makes me think you have a header gasket leak. 

What do you have for valvetrain? Is your vacuum reading steady? 

Here's an example of a rod bearing that's bad., you'll typically hear it under the car, not as much above. 


View attachment 53406

 

[TheDude]

Boy am I going to feel dumb if this is just a loose header bolt or something like that. Thought I checked that, but now I don't think I actually did. I'll check later and would love to find out that I'm just an ***** and nothing is actually broken. Also getting a little borescope / endoscope so I can get a better view of the headers and inside the fuel pump opening. Roller rockers up top, a video higher up in the thread shows this without the valve cover on. Haven't checked vacuum, but I'll have a look later. 

I pulled the distributor yesterday to check for anything obvious there. Not sure what I'm looking for exactly, but seems OK on the surface. Some up and down play that looks like it probably should be there and solid left / right on the shaft. Bearing is quiet and smooth. No chunks or parts coming out of it or anything. 

 

[Kilgon]

After re-reading your entire post I still have not seen where you have checked the valve lash?  I would take a few minutes and at least check it on cylinder 5 if nothing else.   I would  also bring it to tdc and see if you can push down on the rockers and if so how easy does it go down.  As mentioned above check the header gasket and If there is no issue there I would then get your endoscope and look down in the cylinder.  Try to have it at the bottom of the stroke.  See if everything looks ok on the piston and the cylinder walls are fine.      

 

[Steven Salyer]

  Newby  here but wanted to chime in on that noise.  I noticed in the video your running the roller rockers with roller tips on them,  are they the bushed style or individual needle bearings on the fulcrum?  I've seen a lot of these aftermarket  rockers develop cracks around the fulcrum area - some of the aluminum ones I've seen from china with roller bearings are pretty soft aluminum and have no liner between the rocker casting and the small needle bearings and they wear out the aluminum castings developing a lot of slack on the rocker.      

The other potential is the roller tips on them,  if the pin is not sufficient or hearty enough it can distort, bend or wear in the rocker casing,  especially if your running a pretty high lift cam  or have high spring seat pressures.

I would check your valve train as others have advised.  Sounds like valve train noise especially as it has been progressing in your videos from what I can tell.  If nothing else it would give you a chance to check the rest of the valve train - push rods, colasped lifters and such.

 

[TheDude]

Thanks, for the feedback.

OK, I was sort of hoping this thread would die and I even considered deleting it, but to hopefully save the next dude some time, Here goes...

My name is The Dude and I'm an *****. 

That crazy sound that changed all the time and I spent hours taking crap apart, poking, prodding, stressing on, in the back of my mind thinking I might need to rebuild this thing and wasting your time on was....

A header bolt fell out and another couple were loose. 

There I said it. I'll be turning in my tools now. 

 

[trillizo_y_uno]

"Well, you know, if you're into the whole brevity thing..."