I was driving around, minding my own business when my motor starts sounding mildly like a diesel... Instantly I thought "piston slap" and tried to cover the 0.3 miles back to my house, when suddenly I hear a clanking noise coming from the front left side of the motor around the #1.

Shut it down and it wouldnt start back up.

No idea what it could be, but I found my distributor to be VERY loose. So I set the timing back to 0* and it fired right back up. The motor runs but makes a horrible clanking noise when it does.

Sounds blown?

 

Can you rotate the distributor back and forth a significant amount? Was there oil pressure while it was running?

 

distributor rotated enough to cause SIGNIFICANT timing changes, about 45* or so, but oil pressure was up at about 45psi. I played around with it, and I would assume that I got the distributor a tooth off or something since it got less clanky when i rotated it around so that the little mark was no longer even visible. I'll tweak with it some more, but with the timing set by the book at 0* it severely lacks power, is hard to start, and still clanks.

Dist is probably a tooth off, since I'd never screwed with it before.

Thanks guys.

 

I doubt that it pulled itself out, rotated it's gear and re-installed itself on you. Just a guess though.

 

well whatever it is, it doesnt sound good. if its not the dist, what would it be? All stock motor that i've never screwed with before, fires on all 8 cylinders and the oil is free of silver

 

I think the bottom line that RD is trying to make is that, unless the hold-down clamp was loose, which it shouldn't be unless you loosened it, the timing cannot change by itself by means of the distributor rotating. What is the oil pressure at?

 

I was only asking because I was concerned about the distributor/oil pump drive. You would have to turn the rotor to check for excessive gear play. It seems that you have oil pressure and distributor rotation, so I would disregard that for now and concentrate elsewhere.

You may be suffering from a timing chain problem. There is no quick and easy way to check that as far as I am aware. The valve spring load on the camshaft makes reverse lash tests somewhat confusing. It can be an indication if the chain is really sloppy, but isn't the most definitive test. You can remove the distributor cap and monitor the rotor movement while turinging the engine forward and backward. Of there is a lot of reverse rotation of the crank before the distributor starts moving, the chain may be excessively slack.

I would have also suggested a fuel pump or pump push rod if you had an older engine, but you likely don't have a mechanical fuel pump unless you have altered your L03 for carburetor use.

 

I've got maybe about a degree of play at most. any ideas?

Gonna check the firing order when I get home. Sounds kinda like pinging, but doesnt do it under acceleration as much as it did.

The problem only got worse when I set the timing to 0*. Yes I was using my pickup on the #1 wire, so that would indicate a firing order issue right?

 

why would you check your firing order if you havnt mukked with it before?

Sounds like your stock nylon time gear spit out a few teeth (if its is nylon).My 83 Z28 cam factory with a nylon gear.If it did spit out a few teeth and the chain has actually jumped a tooth or two you may be hearing valves lightly tapping pistons If i were you id pull the timing cover off to check to make sure,and hey if its not pooched nows a good time to replace it
In any case driving it at ALL! while its making that noise, is just begging for a destroyed engine

If you really wanna destroy it,drain all the fluids out of it,invite your buddies over and break out the video camera Do a big bakeey till she seizes up completely and then you will have completed your mission double oh 7

Oh dont forget to post the vid

 

mmm cooked daily driver .

Not on the menu for today though. I'll definitely look into the timing gear idea though.

 

Alright. Got it down to a friend's shop. Confirmation of my worst fears, its blown. Gotta find a new motor now. Anyone willing to sell a motor for cheap? Until then I have no transportation.

*insert random incomprehensible swearing here*

 

Hmmm I'm really puzzled. The motor was said to be "blown" so I got towed, but the tow guy put it in the wrong place, and i had to start it to move it (big hill and i'm not cool enough to have thought to ask for help pushing. Besides, motor's blown right?) and the motor was clanking like someone had taken a hammer to the block.

As I backed it into position I noticed that the thing wasnt making the clanking noises inside of a certain RPM band. Does that indicate anything?

 

Inspect the flywheel?

 

hmmm makes sense, i might have totally destroyed something with the flywheel... starting has become murderously difficult (slow starter rev with 14.somethin' on the voltmeter) and it came on slowly, wasnt sudden... didnt lose any power when the clamor got really bad...

But how would that explain that the sound seems to be coming from the #1?


Gaaaaah too much for my brain.

 

I'm reaching, falsly raising your hopes, yet had to bring up the outside possibility. :shrug: I'm evil.

 

Well I'm about 90% sure I need a new motor... and maybe in the process I can sink that L03 of a boat anchor to the bottom of the pacific and replace it with something decent. Just a few questions to make absolutely sure its DEAD.

 

I wandered outside and took a video of the thing idling. hope it sheds some light on possible causes.

http://home.san.rr.com/murraybs/MOV00075.MPG

 

Is it misfiring or down on power? Hard to tell from the short vid, but it sounds like a rod knock to be honest. What were you doing when it started making noise? drving hard? When you try to start it, does it ever make a noise that would suggest a broken flywheel? Pull a valve cover and see if you've broken a rocker stud. Sometimes that'll sound like a rod. I dunno, oculd be a few things, hard to tell by reading a forum, 'ya know?

 

Not misfiring... Timing checks out at 0*. It didnt lose power til I started messing with the timing after the clanking started.

Just popped a valve cover off, no sign of broken studs, though a few rockers were loose, is that cause the thing's cold?

Granted, it is hard to diagnose over a forum, but I'd still like to try anything and everything before I pull the motor to replace it since I'm poorer than the dirt I wash off the car.

 

YOURS SOUNDED LIKE A DEISEL TOO??

Yea dude i just posted a pretty much exact topic last week and well, the second mine did that, my friend had some spare oil in his trunk so i instantly put it in and it stopped....so i dunno man, but it was really weird.

 

yeah, but now its CLANKS too... its not so much sounding dieselish as it is clanky... sounds metallic, like someone's hitting the block with a hammer.

 

Yeah man i watched/heard the video, very similar to mine, but luckily i caught it on time. first thing that came to mind was a pushrod

 

so should I check my valvetrain?

 

dunno man, i dont wanan give any bad advise.....tough to say....but somethings kinda screwed over in there isnt it

 

Well, when mine was making that noise, I removed the engine, and found the #1 rod cap's nuts were able to be removed by hand....so now it has an L05 that I got from a bone yard for a coulple hundred bucks. It's not going to be running against any road-rockets, but it does have a little more est HP than the L03 (180 vs 210), and more torque too.
I'd start by taking off the valve covers and then getting down to the pushrods first. someone else suggested that, so it is worth a shot.

 

use a mechanical stethescope. A long dowle of wood. Force one end of the dowel on your ear, with some good amunt of pressurem and then stick the other end at certain parts of the motor, the noise will change as you go throguh the motor, so evenutlaly you'll be able to pin point what bearing, what pushrod, what lifter....


you said something about a tow truck, did they dent the oil pan?

 

if it were a dented oil pan it wouldnt have been making the noise before the had it towed now would it ....


Brian you need to check to make sure the timing chain didnt break a couple teeth off the gear and it is slapping agianst the inside of the cover if its not that then i hate to say your probable in need of a new engine...

 

double post