Engine tapping after changing spark plugs
 

I was driving the other night and when I came to a stop at a traffic light, my car suddenly stalled. I started it back up, but it was then misfiring. I didnt think much of it, because it happened before a long time ago and I just gave it a tune up and it was fine. However, this time was different. I found which cylinder was not firing, and also found that the plug wire was okay so I thought it was just a fouled spark plug. I decided to just replace all the spark plugs while I was at it. Replaced them all one by one to ensure the plug wires didnt get misplaced. Went to start it up, and the engine was knocking like crazy. The spark plugs were gapped properly, so I wasnt sure what to do except try the old spark plugs again. Put the old ones back in, and the knocking wasnt as bad as before, but it was there and it is random. It would tap every 1 second, then every 3 seconds, then tap a few times in a row, etc. After a few seconds, the car would begin to idle incredibly rough and then stall. So now the car not only randomly knocks, but it runs incredibly rough and is still skipping. I'm not sure what I might have done wrong. I double checked that the spark plug wires are arranged correctly, and even cleaned and verified the gap of the old spark plugs before putting them back in. What I dont understand is why would my car start knocking because of spark plugs? Any advice would be greatly appreciated. Also, no mods on the stock 305.

Re: Engine tapping after changing spark plugs
 

you may have dropped somthing in there spark plug seal or somthing else

Re: Engine tapping after changing spark plugs
 

How much have you actually driven the car since the swap?

Your ECM may have run through a "re-learn" before the motor will act right.

Re: Engine tapping after changing spark plugs
 

Thank you for the input. I suppose it is possible that I dropped something in there, but I was very careful to clean the area before I started and during the work specifically to prevent that from happening. As for the length of time of driving it since this all started, I was less than a minute from my apartment the first night it was acting up. Today I drove about 5 minutes to my friend's house where I replaced the spark plugs. After that, I didnt make a full trip around the block because I was afraid of causing more damage. Sorry if this is a dumb question, but what is this re-learn thing? i've never heard of something like that before. I always thought that the computer components either worked or they were broken.

Re: Engine tapping after changing spark plugs
 

Any time the battery is disconnected, the block learn values are lost and must
be relearned by the ECM. This loss of corrected values may be noticed as a
significant change in driveability. To re-teach the system, make certain the
engine is fully warmed up. Drive the vehicle at part throttle using moderate
acceleration and idle until normal performance is felt.

Re: Engine tapping after changing spark plugs
 

wont have to go thru a relearn just for plugs. check the cap to make sure it is not cracked or have trails in it causing it to cross fire inside the cap. 18436572 is the firing order. go over it again. how bad was a the plug in the cylinder that you found to be the issue? may also want to check the injectors to make sure one is not dumping fuel.

Re: Engine tapping after changing spark plugs
 

The plug wasnt really that bad, but it was wet. I already double checked that the wires are connected according to my manual, but i'll check them again just to be sure. A mechanic friend of mine is going to take a look at it later this afternoon, although he specializes in european cars. He seems to think it could be a lifter issue? I'll see if he can look at the fuel injectors to make sure they are working properly.

Re: Engine tapping after changing spark plugs
 

How are you checking your plug wires? A visual is not good enough.

Re: Engine tapping after changing spark plugs
 

I let my mechanic friend take a look at it and he took the valve covers off and tightened the rocker arms a tad. We put it all back together and it ran better but still not normal. After a few minutes, the car started running properly. As of right now, it seems that the issue is resolved :huh: