Trouble

[JoelOkie]

I wouldn't say the sound is like Barry White gargling with nails. It's more like Barry White hitting his head against something hard repeatedly and really fast.

Now there's a pleasant thought.

[Brad Lustig]

If you've ever had an engine "diesel" after shutting it off, that's what it sounds like, just more rapid

[Joe Flanagan]

If that's the case, then I doubt it's spark knock. But I will go through my process of elimination and then see where that takes me. Onward and upward, I hope.

[Brad Lustig]

Do you have a choke knob? If so, you can eliminate the lean mixture as being a problem if pulling the choke out doesn't help the situation.

[Joe Flanagan]

Brad, I have an automatic choke. I've been having a problem with it closing at startup because the linkage hits the idle speed screw. The arm on the choke goes up, then the linkage binds and the choke won't close. It's something I had planned to get to.

[DutchEdwin]

Joe, just my 2 cents. When I had an Opel (well it's Europe here eh Fred ) I had a metal rattling of the engine when I accelerated on the hot engine. Looked for it for weeks as I didn't know that much of engines like I do now. (in fact still is a little compared to some of you guy's). It turned out to be a loose part on the tail pipe. One bolt of shield was loose, making the shield rattle only on acceleration. To check put some tension on the tail pipe in different directions and see if the noise is still there.

Noise travels, confusing you where it comes from.

Good luck

[Joe Flanagan]

Thanks, Edwin. I will be looking for all possibilities. I have Friday off. My new vacuum advance should be here by then and if the noise is still there after I install it and set the timing, I might begin surgery.

[Jim Saraceno]

Another noise that an engine will make is SEVERE detonation. I has the sound of a hammer rapidly banging on the engine.

I had that happen to me twice last fall and it scared the heck out of me. It stopped as soon as I let off the accelerator. Both times I was going up an incline for a period of time. It has never happened again so I'm thinking I had a bad batch of gas. The puzzling thing is I never heard the "ping" before I heard the "Bang".

[Joe Flanagan]

Well, that's exactly what mine sounds like, Jim. The source of the sound seems to be somewhere around cylinders 5 and 6. If it were detonation, would it be localized to one or two cylinders?

Now that I've had a few days to digest this, I find I'm actually looking forward to tackling this problem. I'll make sure I'm nice and comfy under there, with plenty of light and the car well supported on jack stands. I'll take lots of pictures to share with you all. What better way to spend the 4th of July weekend than wrenching on your old Mopar? OK, OK, driving your old Mopar would be better, I know. But you have to take what you can get.

[rustyzman]

Detonation will make a very sharp, loud, distinct banging knock under loads. It will be a very fast sharp hammering. Can be caused by way over advanced timing, really crappy gas or a hot spot in the cylinder such as a knife edge on a valve or sharp casting flash that is glowing. It is also extremely destructive and will blow holes right through pistons if not corrected. Just had an AC Cobra in here with that problem from the distributor WAY over advancing timing on acceleration (like 60+deg. total). Sounded like someone threw some marbles in the cylinders at speed. If the noise is disappearing when retarding the timing, you may have an issue in base timing or in the advance mechanism. It may be worthwhile to mechanically confirm TDC with an indicator or some such and double check that your timing marks are actually correct and not off.

Also, a quick check would be if it is only one cylinder, change that spark plug. It is possible to have a single cylinder event caused by a bad plug. Cheap and quick check. Just some thoughts.

[Joe Flanagan]

Thank you. My vacuum advance is confirmed defective. The sound you describe matches what I'm hearing. I have confirmed that my timing marks are accurate using the plug above cylinder 6.

[blueskies]

Joe-

Just read through this thread, sorry to hear you've got a bad noise...

When I first heard mine, it was so faint that no-one else could hear it. I tend to be paranoid about noises, and listen constantly for noises that change over time. I could hear something I didn't like, but couldn't find it. I tried pulling plug wires, stethoscope, etc, to no avail. I just kept driving it and the noise kept getting more pronounced over time until I was finally able to hear it loud enough to figure out where it was. I finally found that it was in one cylinder by pulling plug wires and listening to the engine with the stethoscope.

I pulled the pan and inspected the bearings and they were all good. Checked them with Plastiguage again and all good. Finally pulled the head and removed the piston from the cylinder in question, and found the wrist pin bushing cracked and spinning in the rod end. Apparently it was not a tight enough fit.

If you look very carefully at the wrist pins when you pull your pan, you may be able to see signs of a problem. I didn't notice it before I pulled the piston, but there was a crack at the edge of the bushing that was visible before I removed the pin.

I don't know if running too much advance with my HEI caused this, or if it was just a bad bushing fitment done by Vintage Power Wagons. I had the bushing replaced and it has been fine for thousands of miles since.

Hope you find an easy fix...

Pete

[Joe Flanagan]

Thanks Pete. The first thing I did was go back and read your two threads on this problem. This afternoon I got my new vacuum advance and installed it. Set the timing to TDC and ran the engine. No noise for the first fifteen minutes or so. Once the engine warmed up, the noise started. I pulled the plug wire on cylinder 6 and the sound disappeared. Put the wire back and the sound came back. I think I was fooled earlier into thinking that retarding the timing eliminated the noise when the engine wasn't warmed up enough to start making the noise. Taking everything apart on Friday.

[Cpt.Fred]

sorry to hear that, joe. this is bitter...

you're a smart man to test the engine that thoroughly when it is still

easy to work on, many people would have said "hey, it's been rebuilt,

everything is perfect!" and assemble the whole car before they hear that noise...

after this, you'll be quite experienced with this engine,

if that can be a comfort to you.

let us know when you found the culprit!

i keep my fingers crossed!

[blueskies]

I think I was fooled earlier into thinking that retarding the timing eliminated the noise when the engine wasn't warmed up enough to start making the noise. Taking everything apart on Friday.

Mine would make more noise when it was cold... I would cringe when I would start it up and hear that little hammer rapping away in there. Once it warmed up, it would go away. At first anyway. As I put more miles on it, it got worse until it was ever-present.

I would pull the pan first and inspect the bearings. If they look good, then I would pull the head and remove the piston/rod and inspect the wrist pin and wrist pin bushing and the keepers.

From the bottom, you should be able to see the cylinder walls too. If one of the keepers has come loose, there should be evidence of scoring on the cylinder wall. The bearing and cylinder walls were clean on mine, so I knew it had to be the wrist pin bushing.

Pete

[Joe Flanagan]

Thanks Pete. I'll do that. I sure hope I don't have any cylinder damage. I'm halfway tempted to leave work early and get started today.

[blueskies]

Thanks Pete. I'll do that. I sure hope I don't have any cylinder damage. I'm halfway tempted to leave work early and get started today.

With a bright light, you can see quite a bit from the bottom... If you can't see anything obvious, then you will have to start removing parts... I put my camera on the close-up setting and took a bunch of his res pictures with a flash, and studied the pics on my computer. I was able to see things in the pics that I didn't notice while under the car.

Pete

[Joe Flanagan]

Wow. I'll definitely be taking pictures but I don't know if my camera is that good. I plan to post them here to show my progress (or lack thereof). I was planning to get under there with a trouble light so I can see everything. My plan is to pull all the pistons, check all the pins, keepers, and bushings, check the rods and mains, and plastigauge everything.

[Joe Flanagan]

This evening I drained the coolant and the oil and removed the oil pan. Nothing obviously amiss. The oil pan looks pretty clean. There is what looks like little bits of gasket sealer in there from when I had to take the pan off three or four times because of problems with my flywheel bolts. Also tiny, tiny bits of some kind of gritty substance that mostly crushes between my fingertips. Carbon? There's a little debris in the very bottom of the pan but I don't know if any of it is metallic. I guess I can check with a magnet.

Otherwise, the caps are all tight. Nothing seems loose there. I see no scoring on the cylinder walls. Close inspection of the piston pins reveals nothing.

Tomorrow I will start removing the caps from the rods and the mains and checking them with plastigauge.

One thing I did see while I was under the car was that I missed one of the nuts that holds the intake manifold on. It's the stud directly beneath the heat riser, I think. I think Tod Fitch mentioned it in an earlier post today. I wonder if that had something to do with stumbling on acceleration.

Will report more tomorrow.

[Joe Flanagan]

Today I pulled the caps to the main bearings and the connecting rods. All my bearings are scored. They all look like some kind of grit found its way into the engine. Here are some pictures:

The rear main bearing was damaged, but in a different way. It almost looks like galling. Here are some pictures:

The main and rod journals on the crank are mostly OK but there are a few tiny nicks, about the size of a pinpoint. I don't know if it's worth having the thing reground on account of this. I removed pistons 6 and 5, because I thought that was where the noise was coming from. You may remember that I ran the engine with the number 6 spark plug wire disconnected and there was no noise. The clips and bushings in both pistons looked fine, however, in number 6, I discovered this discoloration in the piston pin:

The bushing in that piston looked fine. But here is what the piston looks like:

This is its opposite side, with no discoloration:

Continued in next post.

[Joe Flanagan]

This is the number 6 piston. Note the vertical scratches in the piston skirt. It had these marks on two opposite sides:

Number 6 cylinder, with scoring on two opposite sides to match the marks on the piston. These aren't really deep. In fact, they are not as deep as the cross hatching the machinist put in the cylinder walls because you can still see that pattern through these marks:

So, I guess something was going on with number six, judging from the marks on the piston pin, the piston, and the cylinder walls. I found nothing loose. Again, here is the number 6 piston pin:

Here is number 5, which is completely clean:

I don't know what this is or if it could explain the noise I was hearing. In any case, I guess it's a moot point because it seems I'm looking at a near total rebuild. My cylinders have already been bored out to .060, so I don't have any room left to take out more. There's scoring in cylinder 2 that you can feel with your fingernail. I know my crank has already been ground but I don't recall how much. I believe it was .020 on the rod journals and .030 on the mains. I also don't know if the crank even needs regrinding. I think the only thing for me to do is take the engine out, strip it down, and bring it to a machinist for evaluation.

I put this engine together about 8 years ago and it sat in my garage ever since. It wasn't the cleanest environment, though I did have it covered with plastic and two sheets. There was a lot of sandblasting going on outside, though I kept the garage doors closed. I am going to look at the crap that's on the bottom of my oil pan and also cut the filter open to see if that tells me anything.

[Jim Saraceno]

Wow, Joe, it sure looks like something got in the engine and ate things up.

When you rebuilt it did you clean out all the oil route and put assembly lube on the bearings?

You may be onto to something with the abrasive from the sand blasting seeping into the engine.

[Joe Flanagan]

I was really thorough (or thought I was) when I built the engine. I got a gun cleaning kit and ran a brush and rags through all the oil passages. I was really fanatical about keeping everything clean but either there was something I missed, or foreign matter found its way in there somehow. I did use assembly lube and was really generous with it. I don't think sitting around for eight years helped it. It was covered but there were times when there were no spark plugs in it and the hole for the oil breather tube was open (but covered), so who knows. I might use Jim Yergin's mechanic. I'd like to have him look at it and tell me what he thinks happened.

[blueskies]

I'd like to have him look at it and tell me what he thinks happened.

What a drag Joe... I feel your pain!

I'd bet the assembly lube separated and lost it's consistency and drained out into the pan over the 8 year time span. Resulting in a dry startup. Coupled with the oil pump issues you had, it wouldn't take much to score the bearings...

Pete

[Joe Flanagan]

Pete, I was thinking about the episode with the oil pressure, too. In fact, it was the oil pressure relief valve getting stuck that caused all that. I looked at a web site that shows pictures of bearing failure and analyzes them. Most of my damage, according to that site, is from grit. But there is also damage from oil starvation. There are some places on the bearings that are wiped clean and really shiny.

It could be that this fix will be too expensive and I'll have to put the project on the shelf for the foreseeable future.