Ideas on what's causing my click/tick/rattle noise?

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I know one head has a rear bolt that is stepped, the other is a plain bolt. My 82 truck FSM clearly shows the stepped bolt for the rear of the rocker shaft.

View attachment 1715839382
That's the correct bolt to use with the hydraulic head. The stepped bolt. Interestingly enough, my "unicorn" closed chamber head from 1977 has that same stepped bolt.
 
Pull the stick, no noise... Put it back, noise... The dumbest f'n thing right... But that's what it was... So worth a look...

Great idea, and I gave it a try but that's not it. Stick in, stick out, it still makes the noise.
 
Work looms for the next three days. I'll keep chipping away at this, but any further ideas are warmly welcomed to eliminate internal block issues.
 
I can take a video or audio of this, but I've never posted anything but a photo. How does one go about doing this?
You have to post it on a third party site like youtube and then post the link here.
 
Since this issue is with my slant I'm posting it here, but it could well be about any engine. Sorry for the long post but I'm trying to give as much background and info as possible to figure out my problem.

I rebuilt the slant in my 82 D150. It was fully machined by a reputable shop that does know slants. I did the assembly using Doug Dutra's book and my FSM. I watched and helped as @j par put together another of my slants, but this is the first engine I've built by myself so operator error is certainly a possibility. Other than the alternator, everything used on reassembly was brand new parts.

Once built it fired right up on a run stand for the break-in with no issues. All was well with no leaks so I took it home and installed it in the truck. During the break-in we were working with open headers and hearing protection so if my mystery noise was present it would have been impossible to hear.

Fast forward to test driving and further break-in. The truck has no carpet at all just bare metal floors, and the shifter tunnel was set in place with two screws since I knew vinyl flooring was going in soon enough. However, that makes for a pretty noisy truck to drive which made this clicking problem harder to notice and hear.

After 200 fairly gentle miles I re-lashed the valves. I knew I had a loud rattle which turned out to be from the clutch linkage bar going to the throw-out arm. It was too loose making a ton of noise so I snugged it up and that noise went away. However, there was still a noise, best described as a ticking/clicking, like a lifter out of adjustment. Lashing the valves got them back in spec.

After driving it another 500 miles or so, I still have the clicking/ticking noise and I can't figure out what it is. Here is what I've checked so far at just over 700 miles:

I just changed the break-in oil and filter for regular stuff, checked the timing, changed the plugs, and fixed a valve cover leak.

I lashed the valves again after calling OCG to verify the lash. This was done with the engine hot and running.

I re-checked the head bolt torque, it was good.

The noise is RPM related. At idle you can hear it, and the faster the engine runs, the faster it clicks. When I get to 2000 RPM or more, the noise becomes noticeable louder and more metallic sounding.

The noise does not appear to be gearbox or drivetrain related. It will make the noise sitting still in neutral with clutch in or clutch out.

When assembling the engine, I checked all the torque two times for the main and rod bolts, doing so in 1/3 total torque increments. I don't think I messed that up but I guess anything is possible.

At the suggestion of a car buddy, I sent in an oil sample for analysis but it's not done at the lab yet so results are forthcoming.

To further complicate matters, I only have one ear that works (and that one is mediocre at best) which makes discerning the location or direction of sound very difficult. I can sometimes figure it out by which direction is louder or softer, but for me trying to figure this out while the engine is running is nigh on impossible. I have borrowed several pairs of knowledgeable car-guy ears to help find the sound. Some think it's in the valve cover, some the block, and another thinks it's something external to the engine.

If I have to pull the engine and go through it again I will, but first I want to make damn sure it's not something stupid and simple external to the motor. I'd be pretty pissed to pull the motor, disassemble and reassemble, and still have the noise when done because it's something else.

I have the truck back on the lift to investigate from the underside. I'm going out there today to look for anything that could be loose and rattling when it picks up the right harmonic frequency. I'm calling over a buddy with good ears to take another shot at finding where this is coming from.

All that long-winded preamble is to ask if anyone has any suggestions on what could be causing this, and what to check external to the engine. If so, please feel free to chime in.

As RRR says, thank you and drive through!
Welcome to the World of Madness! I have one too....
 
Could this be ignition pinging? And also, if it's an automatic maybe a broken flex plate.

I don't think so. I ran this thing hard a few times trying to get it to ping (checking my total timing setting), it would not. No flex plate, it's a stick truck.
 
Are you sure it is not an exhaust leak? Do you have a windage tray?

There is no windage tray. I will check again for an exhaust leak. I can check the top of the headers easily, the lower side not so much but I'll give it a go. I don't see any blowby that would help locate an exhaust leak and I don't hear anything using a stethoscope and hollow tube.
 
Have you listened to the fuel pump? there isn't a mechanical fuel pump that I haven't heard make a noise. Good luck with it
 
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Work looms for the next three days. I'll keep chipping away at this, but any further ideas are warmly welcomed to eliminate internal block issues.
The one good thing you got going for you when you finally pull this motor back out and inspect what's going on inside is that you just put it in recently and everything is clean and your knowledge of taking it in and out has been sharpened. And by the time you get it back in your knowledge will be razor sharp LOL...
And when you take it back out this time for god sakes clean the fender walls...:thumbsup:...
 
I knew I had a loud rattle which turned out to be from the clutch linkage bar going to the throw-out arm. It was too loose making a ton of noise so I snugged it up and that noise went away.

I guess you know about setting the freeplay at the pedal? You gotta have at least some, and the TO bearing has to be pulled back off the clutch fingers. There is supposed t be an "anti-rattle spring" down there which does that job. It connects between the TO-fork and the bellhouse where it bolts to the engine; there should be a tiny pocket there to receive it. If not then you can anchor it to anything that doesn't move. After that you can set the clutch freeplay; usually about an inch, but could be whatever you want it to be if you don't mind checking it more frequently. The goal is to set the clutch-departure to some adequate amount that allows a clean shift, especially into reverse; usually about .080 inch...... but could be less.

I don't think this has anything to do with your problem, because you said same noise with pedal down or up. I just wanted to save your TO bearing, lol.
 
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The fuel pump arm that does not return all the way to the eccentric, will go Tick, Tick, Tick all the way through the engine. Even hearing it on the interior of the car.

Take the fuel pump off. Rattle the arm. If you can feel and hear looseness replace it with new. The pump arm/lever should be tight in there. Have had brand new ones that were loose, not a good sound.
 
Lots of good ideas offered by lots of other guys.
I just want to add that, to a trained ear;
>noises inside the oilpan usually have a bass tone to them, more of a hollow knocking
> noises in the valve cover usually are more of a metallic clacking, unless something is hitting the cover, but you can feel that under your hand.
> the crank should have less than .010 endplay. If it gets too much bigger it will develop a random tapping as it bounces back and forth. You can measure this at the balancer.
> wrist-pin noises are rare, but are a double tap caused by the thrust reversal at the top and bottom of the stroke; it is a very distinctive noise.
> Valve-lash you are familiar with. But slantys are a unique case. The rocker-arms are fairly soft, and the valve stems are very hard. So slanty arms eventually develop narrow grooves in them from the stems sliding back and forth. When this happens, you cannot use a regular feeler any more, because it will span the groove, and the groove depth under it, will be added to the lash. Therefore you need a narrow feeler to lay in the bottom of the groove.
Your builder should know this and should have re-ground your arms. But ................ you never know.
> the fuel pump noise, if any, is easy to mistake for other noise, but easy to prove.
> as for the cam walking back and forth, I don't know what that might sound like nor if it is even possible to develop that much play.
> another thing I don't know: if you install solid lifters in a hydro engine, is it possible for the solids to leak oil when they rise up with the cam-lobe? IDK.
> the factory engine had the intake-manifold bolted to the head together with the exhaust, using special conical washers that were designed to maintain their tension as the parts, all three, have varying rates and amounts of expansion; So those washers will act as springs. If you have not reused those washers; I can only guess what will happen.
> if you have forged pistons, I suppose piston-slap could be an issue, if your engine never warms up, or the skirt clearance is too great. This noise usually goes away as the engine comes up to temp; actually, as the pistons swell up. You can check this by, for testing purposes, by blocking off airflow to the rad, until the engine temp comes up to about 200/210. The noise should get quieter then disappear, as the temp goes up.
But this noise comes in multiples of three per revolution, lol, so has a distinctive tempo, as compared to most other noises.
> exhaust ticking is the most common. It follows rpm but often disappears on engine deceleration with closed throttle. And it gets louder as the engine is asked to work, with increased throttle. If your ignition timing is late, the mixture, may not finish burning inside the combustion chamber. If it is still burning and expanding in the header, it is gonna try to get out anywhere it can. You can often find the place(s) by the tell-tale soot marks.
> and finally, a wildcard; ignition snapping noises. Could be a wire not fully seated. Could be leakage, but then you would also have rough-running, especially on a 6-cylinder that only fires three cylinders per revolution; to lose one is a very big deal.

That's all I got, hope it helps.
 
I know that tracking down the source of a noise can sometimes be frustrating. Friend of mine who runs a shop for Studebakers had one with a strange noise that he spent hours trying to figure out. Finally decided it was something in the gas tank. Turns out it was a golf-ball sized lead ball that the owner had put in the tank because someone told him it would add lead to the gas. So it was just rolling around loose as the car accelerated, decelerated, went around corners, etc. The owner was hard of hearing, so he never heard the noise, but it drove my friend crazy until he figured it out.
 
I know that tracking down the source of a noise can sometimes be frustrating. Friend of mine who runs a shop for Studebakers had one with a strange noise that he spent hours trying to figure out. Finally decided it was something in the gas tank. Turns out it was a golf-ball sized lead ball that the owner had put in the tank because someone told him it would add lead to the gas. So it was just rolling around loose as the car accelerated, decelerated, went around corners, etc. The owner was hard of hearing, so he never heard the noise, but it drove my friend crazy until he figured it out.
Oh, my... :BangHead:
 
Take the fuel pump off. Rattle the arm. If you can feel and hear looseness replace it with new.

"New" is a problem in this case. New \6 fuel pumps tend to be much poorer quality than we used to be able to get. They no longer have the arm follower spring—which is what kept the pump's lever arm in contact with the camshaft even when the mainspring was compressed. Without the follower spring, when the mainspring's compressed, the lever arm is free to flop up and down, and in that condition it can easily make a click/tick/rattle when the cam lobe smacks it.

If you go too far the other direction, old fuel pumps pose risks as well—rubber doesn't react well to age, and some of it doesn't react well to alcohol in the fuel—but I had consistently fine results buying and using NOS AC № 6972 fuel pumps. Cheap and easy on eBay, such as this and this.

OP: to check if this is what's causing your noise, unbolt the fuel pump and pull it away from the block. Start the engine; if it was running recently, the fuel in the carb bowl should be enough to run it long enough for you to hear if the noise has gone.
 
Zach, if it happens that it is the fuel pump, I have a few NOS high quality ones. Let me know if you confirm it is and I'll send you one.
 
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