1978 /w 1979 2L Engine Noise

[wdledbetter]

I hate that this is my first post here..... but oh well.

I bought the car last fall, it's a 78 body with a 79 2L motor. Drove it quite a bit, then drained the fuel out of it in November and stored it for about three months. Cranked it back up a few weeks ago with fresh gas, drove it two days no problems. Decided to change the plugs, when I started the car back up I had a nice random metallic clacking in the top of the engine during idle, seemed to stop mostly when the accelerator was pressed. Just to make sure I put the old plugs back in, no changes. Got a flashlight/magnet and fished around for possible debris, etc. Nothing.

I let it sit a few weeks until this evening, put the new plugs back in it, cranked it and the sound was none stop this time. I don't know if it's because the engine was cold... or simply the problem got that much worse. Now it's definately RPM related. I have not checked timing and the cam belt yet. I'm beginning to think it's not related to the spark plug change, but coincidental and of course all of the typical fears!

Also, the engine responds to the accelerator well... It does not seem weak.

Cold Crank and Sound:

http://www.youtube.com/watch?v=MdbTWmnr6X4


Thanks for any help!

[RRoller123]

Man that is an odd sound. Should do a compression test. And check to see if maybe exhaust manifold is cracked or loose.

[So Cal Mark]

it's important to blow out around the spark plugs before removing them. Pretty common for debris to fall into the plug well. The problem is that the debris gets hammered into the piston or head since they are both aluminum, and it's stuck there until you remove the head and dig it out. I'd try to pinpoint which cylinder has the noise using a stethoscope, then remove the plug and put the piston down where you can see most of the surface

[wdledbetter]

Thanks for the advise guys!

If I pull the head... it will be the first time I've pulled one off a Fiat. Are the head bolts torqued enough to be stretched and need replacement?

[SLOSpider]

You can reuse the head bolts. You can get the head off in a matter of a few hours on your first go around. Sometimes its easier to loosen the exhaust bracket under the car on the trans and loosen the exhaust manifold off the head rather than to fight with the flange. You can leave the intake on. Remove the air cleaner, radiator and heater hose to head. pop the distributor out and wires. Remove the head bolts and pop her off. I would first verify where the noise is and make sure its just not an exhaust leak. You can also try to remove all the plugs and crank it over to see if it will blow anything out the plug holes.

[majicwrench]

That is not an exhaust leak. You will likely be able to pull plugs (BLOW AROUND PLUGS FIRST) and see which one has some damage showing. And/or peak down plug hole with small flashlite and see damage. If you can figure out which hole you may even be able to see the piece of offending junk and fish it out. Or get creative with shop vac taper hose down to vacuum hose and stick it in hole and work it around, or stick shop vac full size hose over hole and crank engine over see if you get luck. Might try a small magnet on a copper tubing down the hole see if you get lucky. Might just rev it for a bitr and see if it will spit it out. Last option is pull head.
Keith

[wdledbetter]

So it's been awhile, but a few months ago I finally had a chance to pull the head. I tried EVERYTHING to figure out what was going on. I was 90% sure the sound was from the number 4 cylinder. I pulled the head to find a copper grommet laying on the piston. I was too the side so I never could see it with a flashlight and of course a flexible magnet would not pick it up. I could hear the magnet moving/touching something occasionally and just tell what it was.

Put it back together again earlier this week and the fuel pump decided to die after sitting for so long.... it's still got the old cam driven/mechanical pump so I'm going to put an electric one in it next week.

If I keep gas dripping down the carb it runs great, used a bulb and pushed gas all the way through the lines after checking for blockages, etc. It pushed all the way though the fuel pump and filter and out the tube at the carb, still wouldn't crank. Even tried the 60-90 second continuous crank mentioned in other posts.

Ironically, I know where the copper grommet came from.... the previous owner/crappy mechanic that worked on the car put a head gasket on it and tore the copper grommet out of the head gasket where it fix over the rear post on the block. I assume they were trying to get the head on the posts without the head gasket moving around and took the short cut instead of putting a touch of sealant around the posts to hold the gasket in place. It's the same grommet that was embedded into the new head gasket. So I assume they dropped it when they yanked it out of the old head gasket and dropped it on top of the head and down into the back plug well....

I found out the HARD way to always vacuum out the plug wells. At least I'll be back to driving it shortly!!