Weird Engine Noise

Hello,

Wish I had a better reason for my first post. I purchased my first old Mopar and first classic car in general this past April, a 66 Coronet with a 440. The engine itself is a 77 block which has been upgraded with new rods, pistons, agressive cam and I suspect close chamber iron heads. Unfortunately I don't have any paperwork/info on it, as the previous owner bought the motor from somone else who built it for a drag car but gave up on his project, so it ended up in this car. Its definitely a pretty potent engine, so I'm inclined to believe what I was told, definitely not a truck/motorhome engine.

I haven't really driven it more than a handful of times due to the craziness going on, but last week I figured I should get it out before the weather gets bad. Started her up, let it warm up and set off, I almost immediately noticed a ticking/chattering noise I hadn't heard before but figured it was probably just a sticky lifter and it would go away after it was run for a bit. When I got on it or was just crusing around, I couldn't hear anything other than the usual lifter noise, however upon deceleration when approaching a stop, the noise would return very distinctly from about 1700 rpm down to about 1100 and then would dissappear again as the car returned to idle (which is set at 850rpm). The same thing occurs when you first set off, you hear it for a second but as soon as the car reaches about 2000rpm, it seems to vanish.

Figured I'd try is changing the oil just to see if it would make a difference, the previous owner told me it was changed in spring, but it was very dark, so I'm not sure if that's accurate. The magnetic drain plug had no obvious metal particulate, and other than being dark, the oil didn't show any obvious suspended metallics. Put in a new wix filter and VR1 10W30 oil. Took it for a drive and while better, the noise is still there. Same rpm range, just not quite as loud.

The only other thing I figured I'd check is the old oil filter, see if there was any chunks in there. Cut it open and definitely see a little glitter, mostly in the oil itself, there are a few flecks stuck in the filter material itself but not much at all. Sort of gold-ish/silver in color. I'll try to attach a picture (sorry for the quality), the orange bits are engine paint that fell into the pan while I was working. I know a little metal is normal, not sure how much would be concerning.

The car idles, isn't down on power and has great oil pressure. Obviously, i haven't driven it very far since the noise started, and would like to fix it before I grenade the engine if its something serious.

So what do you guys think? I'm no mechanic and really don't know much about engines other than basic service so I figured it would be better to ask here before I jump to conclusions. Sorry about the long post but I figured the more details the better.

Thanks,
Dave

Welcome aboard from NJ. Someone is bound to chime in. I have never encountered anything like that myself. I would recommend listening with a stethoscope to to try to pinpoint the source! You should have introduced yourself in the welcome wagon first, but you can do that later.

Hello and Welcome to the site, have you tried to listen to it with the hood up to see if you can hear were it comes from?

I hate to say this but those bits don’t look good. That gold color is typical bearing failure stuff. Been there, sucks. I’ve also been in the “I’ll see what happens” spot and grenaded a nice 440. I was 17.

I’d pop the steering link and drop the pan. Then one by one pull the bearing caps and put them back. You won’t sleep well until you do.

rod bearing.

Nate S said:

I hate to say this but those bits don’t look good. That gold color is typical bearing failure stuff. Been there, sucks. I’ve also been in the “I’ll see what happens” spot and grenaded a nice 440. I was 17.

I’d pop the steering link and drop the pan. Then one by one pull the bearing caps and put them back. You won’t sleep well until you do.

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Thanks for the replies. Kinda what I figured I was going to hear, unfortunately. I'll drop the pan and see what I can find, pan was leaky anyways.

I attempted to pinpoint the source with the hood up and laying in front of the car, but with solid lifters, basically straight piped exhaust, in a metal garage, its hard to clearly hear anything lol. It also doesn't help that the noise is most pronounced when the car is in gear.

The other thing I forgot to mention in my original post was that the previous owner said that it would ping if you really got on it, even with 93 in the tank. I had it tuned by my local mechanic who's also a mopar guy shortly after I bought it. He agreed it likely had close chambered iron heads on it and is a pretty high compression engine. In addition to the tune up,, I've always added octane booster when I fill it up and never noticed any detonation, but who knows how happened before I bought it. Might also look at changing out the heads (or using a spacer gasket, if they make them for these engines...) to achieve less compression so I can just run it on 93 and not have to worry about it. Any suggestions on good aluminum heads for a high performance street application?

Welcome to the forum!
Sorry about your issue.

6Coronet6440 said:

Any suggestions on good aluminum heads for a high performance street application?

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Depends on if you want to retain factory appearance or not. There are quite a few choices depending on what you wanna do appearance wise and power wise.