Thread: Motor Vibration?! Timing Chain?

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Hey guys, I'm new to Club Hot Rod. I've got a 68' Monterey with a 390 FE. From what I know it has the original cam and crank and nothing special done to it so far.

I recently replaced my timing chain and sprockets. Now at higher RPM's I get a horrible rattle, clanking noise(unfortunatly I don't have a tach). The noise doesn't seem to be consisnt or in rythem with the RPM's though. I can't seem to hear it at all at idle or if I just feather the gas. It almost seems like it may be off balanced maybe? It seems to run good, idles a little rough. I haven't timed it yet due to my piece of crap timing light.
The old cam sprocket looked like it maybe was aluminum, coated in a very hard platic?! anyway it had a tooth broken off of it. The new one I believe is steel, def. much heavier than the old one. It seemed to line up good with the new crank sprocket and the chain seemed straight. I pre-lubed the new chain. I don't know if maybe the weight difference between the old and new cam sprocket would matter or maybe just timing it would take care of the rattling?
Any suggestions or input would be greatly appreciated. Thanks

Thanks a lot Denny, I'll try to get a timing light from someone and get it in time.

Just an update in case someone comes across this and has an idea. I timed it and I'm still getting horrible vibration and noise. More on the down rev, if i get into the throttle and let the motor come down to an idle it's worst. I tore it down to the chain and sprockets and found nothing out of the ordinary. I ran the motor with no accessories (I replaced the waterpump when I had it off and wanted to make sure it wasn't that) still made noise and vibrated.
A couple things I'm thinking about now are maybe my harmonic balancer is at fault. The rubber is pretty weather checked and cracked. The motor ran very smooth before tho. The other thing is I replaced the washer on the frt. of the cam that holds the fuel pump essentric on and the dowl in place. Could a different washer on the frt. of the cam throw the motor out of balance enough to make a noise and vibrate? Any help would be greatly appreciated guys. thanks

I had a dampener spin on me one time on the 5.0 I put in my Jeep, thing vibrated like mad, especially at higher rpms. New dampener fixed it right up.

Don

Sounds like the damper all right.

You probably have the spark plug wires on wrong on the left side of the engine---no 7 and 8 need to be separated to eliminate crossfire---the wires generally ( from factoy) are 7, 5, 6, 8---and after many tune ups they get put bac 5,6,7,8 which has 7 on 5, 5 on 6, 6 on 7 which creates vibration, rough running engine just as you described

Jerry

oh---- if you want to you can run the engine without the front cover or water pump and dampner----use your timing lite on the coil wire for a strobe and you can see what the chain and gears are doing in stop action like light.

You will have to supply fuel to the carb by manually strking the fuel pump

Thanks for all the input guys, I'll see if I can't try some things this weekend.

Kam,
By chance, did you happen to not use a puller and instead pried the balancer off using a big pry bar?

If it's not the firing order like Jerry said my vote is the damper spun. Sounds like it gave up the ghost and didn't survive the swap. Pro Products sells a very nice replacement for $70. On ebay all the time. Should come with a new timing pointer. I bought the SFI version for $130 last year and it's very nice.

robot,
no I used a puller and it actually came off pretty easy. But it does look like she's seen better days.


FFR428,
thanks for the input on the balancers, I was actually just trying to find a new one but I didn't know what to go with.

Hey friend, post pics of your monterey. I have a 69 2 door, pristine cond. If you try to run it without the timing cover on you could also use a cruddy inline universal fuel pump. I find that keeping a few of those and some fittings around always helps to troubleshoot my own (and alot of other peoples) stuff. Good luck, and post pics. Maybe then we can sit back and talk about how much we love montereys.

The other day I nearly had to sock someone when I said I had a 69 monterey and he asked if they made mini-vans back then.

soldiers-rod
Yeah I'll try and get some pics of her up. She's a little rough around the edges but I drive it almost everyday. It's very mechanically sound. I"ve taken her on some pretty long road trips and she hasn't let me down yet. I figured out the rattle noise and vibration. I didn't remove the little spacer in between the cam sprocket and cam and the new cam sprocket had that spacer built on. Some how I completely missed that. I guess I was worried about getting the engine out of time. So my fuel pump eccentric was hitting the frt cover. It was pretty loud! Well I guess you live and you learn.

Glad to hear it Bro, names Mike. You can reach me at Michael.LaPietra@us.army.mil for email if you want. We did a front end restoration on my car. (all it needed.) We scraped grime off of stuff, laid down new enamel, everything. You cant look under my hood without seeing either fresh enamel, chrome, or steel braided line. The bottom is now rustproofed and everything. Look at the car from almost any angle and it looks new.

Soldiers-rod

Wow sounds expensive, but a really nice ride. I'll try and get some pics up this weekend. I'm kinda busy looking for a place to open up a garage but I'll c if i can make time. Names Derek by the way.