Vintage Mustang Forums banner

1 - 8 of 8 Posts

·
Premium Member
Joined
·
2,294 Posts
Discussion Starter #1
One day, engine is quiet and has no problems. You start the car up to get ready to go for a ride. Out of no where you suddenly hear a noise. A slight tapping noise, tap, tap, tap. You let it idle, and you no longer notice the noise. You run some Marvel Mystry oil through it, flush it out, and change the oil. You start the engine and you hear the noise again. You walk inside while its idling, you come back out, and the noise is considerably louder, almost a rattling like a rod knocking, and the engine acts as if it wants to die. So you shut the engine off. Also, the timing has never been right on this car. It will not stay in time for the life of me.

My Theory:

I have not driven the car buy maybe 50 miles since I have had it, just test runs, etc. The guy I bought it from was blind and sick, and he didn't know much about the engine, because the guy he bought it off of had installed it. It didn't run when the blind man got it, and he and a friend wired it up and got it to run. Then it came into my position after it sat for a few years. I changed the intake and carb when I first got the car. The lifter gallery had No carbon or sludge in it, almost clean. I took the valve covers off last night..... The oil return holes and top of the heads are spotless. Just black with oil as they should be. This engine looks clean enough that it appears to me it has been re-built. So what if the blind man didn't break the engine in right, didn't break in the cam, etc? I had no idea, so I had been driving the car regularly. Could I have destroyed this camshaft, lifters, and maybe even the bottom end of the engine? Please tell me what you think.
 

·
Registered
Joined
·
3,220 Posts
Most likely it has been dry started too many times. If the motor has set for extended lenghts of time as you say and is started there would most likely be no oil to the bearings. Check the bottom bearings and see if they are scored very bad.
 

·
Premium Member
Joined
·
2,294 Posts
Discussion Starter #3
I could understand that, but, I mean, I start it at least once a week...... How could it be fine all the sudden, no problems, park it in the garage for a few days, come and start it up and "Taps, knocks, etc" comming from it? I mean, I would understand if I let the engine sitting for 4 months then I tried to start it, but It was ran a few days before this happend, and it didn't act weird then.
 

·
Premium Member
Joined
·
2,294 Posts
Discussion Starter #5
So do you think I should drop the pan and change the rod and main cap bearings? While im at it, go ahead and change the cam and lifters, plus hardend push rods, and make sure everything on the top is taken care of? I want to get this damn thing drivable, and everytime somthing gets fixed, something else go's wrong!
 

·
Registered
Joined
·
7,671 Posts
If you have a bearing knock, it's time for a crank kit or a reground crank.... Oil pressure reading would really help narrow this problem down...
 

·
Registered
Joined
·
10,587 Posts
Coupla questions....

What's the hot oil pressure at idle?

Does the knocking noise appear to be at crank rpm and does it get louder as rpm increases?

Were any of the rockers loose when you pulled the valve covers?

What did the oil look like when you changed it the last time? Anything odd looking about the oil or in the drain pan?

This is one of those times when it's better to be there and listen.....lots of things come to mind but wild speculation won't get you down the road...

Get back to us...
 

·
Banned
Joined
·
1,565 Posts
Here's a curveball for you:

VERY similar symptoms on my buddy's '69 Firechicken. We thought for sure rod bearing. The noise was EXACTLY once every revolution (twice per rocker cycle). Noone will ever guess what it was: loose and missing torque converter bolts.

Because now I'm halfway into this post and never bothered to check which tranny you have /forums/images/icons/smile.gif, I'm also inclined to give you the "determine oil pressure" advice. Also, try running the car with the valve covers off, and see if everything appears normal.
 
1 - 8 of 8 Posts
Top