Our 97 Town Car, 4.6l, low miles, has been stored since December. Went to start it and it knocked hard and loud. Shut it off. No evidence of mice or pests. Have no reason to suspect crank or rod problems. Had been running like new. What do I look for?
Not too bad. I've had them off of a Cougar which is tighter than the CV I believe. Yeah, just remove the valve covers and see if any of the cam followers (like rocker arms) have fallen off. They aren't too hard to get back on if so.
Does the oil light go off when you start it? Can you tell which side of the engine that the noise is coming from?
It's my brother's car and I wasn't there when he started it up. I believe as soon as it fired, the noise was so startling that he shut it off right away without taking the time to check the lights. We're going to take a look at it tomorrow again (it's out of town) and I'm trying to have some plan for then.
Thanks, Jimmy. I think you have the right idea. We started it up a couple times today, shutting it off each time as soon as it fired. The knocking is coming from the forward part of the passenger side rocker cover. We trailered it home where we'll eventually get to it.
Thanks again for your help.
Let me know what you find out. This seems to happen sometimes when these engines sit for a long period of time. The lash adjuster bleeds off and sometimes a follower will slide out of place.
I spent a little time on the 97 Town Car 4.6L today and so far no good news. The passenger side valve cover won't clear the a/c unit on the firewall, but I could raise it quite high and see pretty well all the cam followers. They are all in place and nothing looks wrong in the cam area. I pulled the front plug on that head. It hadn't been firing and was wet with more than gas. I stuck a blowgun thru the plug hole, shrouded it with a rag, and gave it a short blast of air into the cylinder. Nothing blew out to soak the rag, but the blowgun tube had about 15 drops of what looked like rusty water or coolant clinging to it when I pulled it back out. I pulled out the 2nd plug on that head and it looked good and had been firing. The oil dipstick showed clean clear oil. Finished on it for now. Plan on cracking open the oil drain plug for a sample in a glass. Then pull the rest of the plugs so I can crank slowly from the front bolt to find the noise. Maybe then a leakdown test starting with that front hole.
My brother bought the car new and it now has 49,000 miles on it. Any thoughts?
More: I cracked the oil drain plug. Just oil. But after taking out the plugs, it's Houston We Have A Problem. Turning the crank by the front bolt, the #1 piston doesn't move. It's up like at TDC and stays there for the full rotation. Since we started it a number of times(for just a second each) without punching a hole anywhere, I'm suspecting something wrong with the wrist pin area of the piston.
Now it's months later. We got a boneyard 4.6l with 63,000 and had a shop install it. Total cost under $1000. When pulling the engine, there was a shot-glass or so of coolant above the piston in the dead hole. It looks like at start-up after sitting over the winter there was probably enough coolant above the piston to hydrolock and bend then break the # 1 rod. The fragments of the broken rod had a slightly bowed curvature in the direction towards the adjacent cylinder. We suspect it bent that way, then broke. Neither end was seized either on the crank or the wrist pin.
Thanks to all you guys who helped out here and in my post of 4-4-08.
Again, thank you all. This forum is an invaluable resource on all things Ford.
