engine knock/valve chatter

[red107]

Yesterday I was out for a drive cruising at 60 mph for about an hour. As I approached a small town I noticed a knocking noise sounded like valve chatter but I wasn't sure. I immediately returned home about 5 miles. My car will not idle any more. The car now sounds like a VW beetle. I also lost power. There was no white smoke coming out of the exhaust. I looked at the engine and couldn't notice anything, However, After sitting for about two hours there is now a small pool of oil underneath her. I can't see were its coming from. I had the engine rebuilt about ten years ago and it has about 5k miles on it since the rebuild.

[focodave]

red107,
It's tough to guess at what went wrong, with the limited information we have to go by -- but I might venture a guess that the timing belt has jumped a tooth or two on the cam gears. That would not explain the oil puddle under the car but it might explain the other symptoms you shared.

[wizard124]

That's lousy

Giving some thought to your issue, I would go after the simple things first.

Check your oil level. Did you run it dry (accounting for the volume of the puddle)?

Inspect the engine thoroughly to try to determine where the oil is coming from. Cracked head or block?

Fore/aft movement of the crank will cause some knocking from worn/mis-installed thrust washers (Happened to me once). You will observe this movement with car running.

Reach under the cover and feel the tension in the timing belt. Since the engine rotates CW as viewed looking at the crank pulley from the front of the car, the belt will be loosest on the passenger side prior to the exhaust cam. Is it loose? Could the belt have slipped some notches resulting in lost power and the aux shaft knob clanking on the rod? Are the timing marks aligned properly?

Pull the plugs and compression test it. This will tell you which cylinder(s) is the problem.

Remove the cam box covers and look for bad cam lobes, tappet not tight against the lobe, etc.

Pull the head and fix.

Pull the engine and fix.

[red107]

Thanks for the input. I know its hard to diagnose engine issue with out actually having it in front of you. Ignoring the oil issue, you think timing would of caused the the valve chatter noise I was hearing? I will inspect the cam belt. I am limited in time. Does anybody know of a good Fiat mechanic in North Carolina? We are here for another 18 months (finally leaving military life) before we head back to Florida. I know of a few in Florida. But I don't want to wait 18 months.