I have a 1990 Civic h/b. Last night when I got home, I noticed that the engine was making a hard tapping sound, like a small hammer. I opened the hood, and noticed that my 4th spark plug boot was completely loose. When I pressed down on it, it felt like something was banging the injector from inside the valve cover. I guess that's why it shook loose. It's an older car, so I know it might need a valve adjustment, but is it possible for valves that are out of spec cause such hard tapping? I'm afraid to drive the car, it's tapping so hard! WHAT COULD IT BE?

 

could be a spun bearing .. thas what mine sounded like when it happen to me .. but my car would also have a jerk everytime i would shift ?? take it apart look at it!!

 

if it sounds liek rocks in a blender its probably rod-knock. but its the stock motor so no worries, 100 bux for the motor and you should be back on the road. however this might be the time to get into some of this b-serieZ action

 

yup...definitley blown rod......believe me I know.. Now is your chance to put together a helluva engine swap, and be faster that you thought you could be....b20/vtec or h22!!!!!!! Good Luck

 

well technically it's not a blown rod persay. what is actually happening is that the rod and crankshaft are making contact.

 

adjust the valves that might fix it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chronic_SMOKE &raquo;</TD></TR><TR><TD CLASS="quote">adjust the valves that might fix it</TD></TR></TABLE>

Dude..I would bet that it is beyond that.......

 

Well, when I started getting ready to take the valve cover off, I pulled the plug wire and it snapped... So, I got some new ones, and then noticed that the spark plug was loose. Tightened it back up, fired up the motor, and woo hoo! PROBLEM SOLVED! However, after seeing all your responses, I'm thinking it might be something else in addition to it? The sound and tapping are gone, now I just hope that it's not a coincidence...

 

woo hooo score!!! I thought you had thrown a rod for sure. WOW! But look into a b or H series swap anyway!!!!!!

 

The tapping noise could have been the spark arcing inside the spark plug tube or something. Happens all the time when the spark plug wires get old.