banging from the head

scotty · Post by **scotty** » Thu Dec 21, 2006 6:15 pm

I was driving for about 45 minutes on the freeway, and the engine started making a loud banging noise. I cut the engine and coasted to a stop. It was pitch black and I had no flash light, so I towed it home. When I checked it out the bolts holding the air cleaner to the intake manifold were missing, and it was just hanging from the hose. I pulled it off and started it up, with no noise. I thought I had figured out the problem until I heard the banging for a split second on start up a few days later. I checked the valve lash and it was ok, and when I put the valve cover back on and started it up, it's now banging continually. I checked the compression and it's 120, 120, 90, 90 Should I even bother trying to re-torque the head or just pull it and go right to the machine shop?

keith0alan · Post by **keith0alan** » Thu Dec 21, 2006 7:30 pm

Pull the head to minimize further damage. Hopefully it was just a washer. Let us know what you find.

keith

Victor_laury · Post by **Victor_laury** » Fri Dec 22, 2006 9:26 am

Sounds like when i dropped a vavle seat.

What part of the City are you? I'm near Glendale toward downtown

spyder · Post by **spyder** » Fri Dec 22, 2006 1:19 pm

My .02. Like Vic I had a seat drop when I stopped to get gas. Restarted the car.. bang bang bang bang. It had a dead cylinder and being the lazy bum I am I drove it home. I would suspect you injested a part because all your cylinders have compression. If you can't get it out of the spark plug hole, the head comes off, before you break a piston or the head.

scotty · Post by **scotty** » Sat Dec 23, 2006 12:20 am

Hey Vic, I live in Atwater, about 6 blocks from Glendale. I'll send you a message when I get back from vacation. If I did drop a seat, it will be the second time in a year. (2 different heads) Thanks

scotty · Post by **scotty** » Sat Dec 23, 2006 12:24 am

I just occured to me what may be in there...one of the missing bolts from the air cleaner...is that possable?

Post by **spl310** » Sat Dec 23, 2006 7:32 am

Yes, it is possible. A buddy of mine has a nice pencil holder (follow me here...) It is actually a piston from his old Land Rover. One day, the aircleaner nut unscrewed itself on a dirt road. The aircleaner bounced off and the nut fell into the carburetor. It made it past the butterfly and the valve without causing damage to them and then seated itself on the top of the piston. With each stroke, it got hammered into place on the piston. If you take the pencil holder he now has and turn it upside down, you will see the impression of the nut that is about halfway into the head of it!

Dave · Post by **Dave** » Sat Dec 23, 2006 8:12 am

And given that it was a Land Rover, it probably just kept running happily along like that for the next 200,000 miles....

Post by **spl310** » Sat Dec 23, 2006 8:39 am

It was in Panama. The truck was old when he got it and had been abused. He replaced just that one piston and put it back together. It ran fine and he sold it when he left. They are tough!

Post by **dbrick** » Sat Dec 23, 2006 11:30 pm

I never like the idea of anything inside the airfilter that can fit down the carburetor. I was going to drill the bolts and put a safety wire through them, but I didn't. Guess what I will do tomorrow?

As far as Scotty's car, If you can borrow a bore scope, take a look around in there if you are not going to pull the head. Unless there is a compelling reason not to, I would pull the head.

I have a similar pencil holder from my Fiat. Broke the timing belt while cranking the engine, replaced it and restarted the car. Ran OK for the first 5 minutes, slight miss, then the bent valve broke at 3000 rpm and the valve head punched a 1.5 inch hole in #2 piston and wrecked the head. Lots of fun changing a piston with the engine in the car on an X-1/9 in mid winter.

Post by **spl310** » Sat Dec 23, 2006 11:49 pm

I owned an X 1/9 for a while. After we paid, we made it exactly .8 miles before a rod came loose, broke the block, it sucked a valve and destroyed the head too. That was an expensive drive...

Post by **dbrick** » Sun Dec 24, 2006 12:02 am

It's actually an equation, Where "X"=running and 1/9 is how often it does.

DELETED · Post by **DELETED** » Sun Dec 24, 2006 11:53 am

DELETED

Post by **dbrick** » Sun Dec 24, 2006 7:25 pm

It's funny, Mark and I discussed this...We all seem to have had the same cars over the years. Fiats, Saab turbos.

SLOroadster · Post by **SLOroadster** » Sun Dec 24, 2006 9:24 pm

Bolts getting sucked through the carb, thats why locktite was invented. The first roadster I rode in sucked a small stud from the carb through and into the #3 cylinder. It made a horrible noise. It turned out to be a lucky thing as the engine was poorly rebuilt, the head was cut rather than being straightened, and there was a crack in the block someplace (Vic, you know the car I'm talking about, Black 68 2000 with a tan top and interior.) At any rate, the engine came apart to find that it was about to granade anyway.

Weather its a bolt in the cylinder, or a dropped seat, its not good.

Will