About two weeks ago, I noticed a slight vibration in the motor. At first I though it was something in the driveline, but it does it in park/neutral as well.
Motor mounts are tight, tranny mount is tight, carb is clean. Also, roughtly the same time, I noticed a ticking near the 7 & 8 cylinders. I dunno if it is a loose rocker or lifter. I tightened the rocker bolts to 25 ft lbs as per the factory Ford manual and did it according to their procedures.

The motor is fairly new, rebuilt about 10 years ago w/RV style cam, headers, carb ect.

About 6 months ago I put in a double roller timing chain, edlebrock performer intake w/o EGR and new dizzy.

Could the vibration and tick be related? Or...balancer? It does it at idle, and about 40-45 mph.

 

compression test engine and also need to check the dampner up in front of engine and make sure dampner hasn't spun on hub. If you don't find anything and vibe still exist might be a possible piston skirt broken off on piston. Have to pull oil pan and do further investigation. confirm rockers are moving up and down and not a flat camshaft also. good luck!!!

 

I guess I'll have to break down and pull the valve covers. I was dreading this as I couldn't seem to find gaskets for the M/T valve covers put on 10 years ago. So I had to cut some and use a lil' RTV. Oh well I guess!

Ill check the dampner, and check the timing as well. I put a DUI dizzy on it and since then, timing has been dead on, I'll check to see if it has "changed".

Truck still runs great! Power band hasn't changed, and runs like a raped ape.

 

UPDATE:

Noticed earlier today that ticking only begins once driven a little bit, warmed up.
Pulled the plugs, they were all a nice light tan/white color....EXCEPT for the number 8 cylinder. It was a little darker, when I went to pull that plug though, it was barely tight. Actually I wouldn't even consider it tight. So I'm thinking that it just leaked...causing the ticking.

I haven't driven it to see if the ticking has stopped, but I let it warm up to operating temp and rev'd it up and let it idle for about 10 minutes, no ticking.
Still have that vibration though...

Checked timing, it's still dead on and steady...so does that rule out dampner? If it had twisted around, then the timing marks would be "off" right?

I then bumped the idle up to about 1000 rpm's in park, and it drops to about 800 at idle, and it seems to not vibrate as much. I like the idle more around 650-700, but vibration is more noticable then.

Did a compression test on the 2nd bank only as thats where I heard the ticking.
CYL
5 - 128
6 - 118
7 - 129
8 - 130

Should I be worried about #6?

If it matters, I did #6 last, the battery was getting a little low on juice by that time. Dunno if that would effect readings.

 

On the loose spark plug was their any black around the plug like compression getting out spark plug instead of exhaust. Sometime you can get a small tick and its a exhaust noise sneaking past sparkplug?? On the compression test this is #6 is in question? Sometimes if engine has some miles you could be getting some piston slap in cylinder due to wear. your getting closer to the answer and process of elimination is the answer and good luck. If timing still good would rule out dampner. If dampner you'll probably notice the rubber pinching out on the sides excessively. the #6 retest and make sure good voltage. A lot of the times I like to do compression test with all sparkplug out and test indiviually. the darker plug might mean not firing well and this could cause a imbalance/vibration. Is the vibration consistant with rpm or occasional? need to check spark plug wire and spark plug. Simple test is to install new plugs or if curious install dark plug in different cylinder and see if plug cleans up and the other plug gets dark. Normally you just install new plugs. Also inspect distributor cap and make sure contacts clean inside cap. Could be a damaged plug wire end and sending weak spark to plug. good luck and we'll talk soon. usually home late in evening and do checkup on ford truck site. forgot to mention if plug loose this means loose ground. plug has to be tight to have proper grounding and good spark. just like having a loose ground on battery. bad ground, weak spark plug energy= dark plug??

 

Thanks wyoming!

The plug wasn't DARK, it was just a little darker than the rest. It didn't look fouled up, just almost like it wasn't getting a good spark. It may very well be plug's/wires. The distributor is only 5 months old, but the MSD wires are probably 5 yrs old! Guess when I get money I will replace them (as with the distributor I have, it needs MSD style wires or better) when I have a little money. I did put the plug in another cylinder to see if it would turn tan. I also didn't see any black around that I noticed, but really didn't think to check for that, so if it's there I missed it. I'll be able to tell today when I drive to work if the ticking stops. That plug was LOOSE, I could of just put my fingers tips down on it and taken it out without using an wrench.

Originally the #6 cylinder was never in question, as the ticking is/was coming from further back, I just tested it because it was the only one on that side I hadn't tested so I figured I would. But now..?

The motor was rebuilt in 95 or so, and probably has close to 200,XXX miles.

 

did you have all the plugs out and throttle open for the comp test?

 

I didnt have all the plugs out but I did have the throttle open. Could that effect readings or are the plugs removed for ease of turning the motor over.

 

with all the plugs out you run much less risk of killing the battery and the motor spins faster/more uniform throughout the test. #6 still doesn't look to be low enough to worry about, coulda just been the loose plug & exhaust leak, hopefully? but things kinda happen with 200k on the clock

if you do pull the valve covers you might want to measure the valve travel of each @ the spring/retainer to verify cam lobes are still there. a severely worn lobe will show as a loose pushrod and will eventually get bent if rev'd

 

Good to know,

I may just be reading into this too much, and could be something so simple as needing plugs and wires.

I think the tick is gone, drove it this morning to work/school and no tick. I think what I did was accociate the tick with vibration and tried working harder, not smarter

Either way, I've had this thing idling so smooth and nice that you couldn't barely feel it at a stop light. Even now, it's not BAD, just noticable in the seat little. I have sat in newer cars that were worse though. It's not a rough kind of "miss" idle.

Next week I'll check compression by pulling all plugs and also check the 1st bank, just for record.