93 honda civic 2 dr ex coupe 1.6 vtec auto trans

If the engine is under heavy load or heavy deceleration, it won't knock but around 2000 rpm, under slight load, I will hear what sounds to be a rod knock. I have driven for at least a thousand miles like this and it runs perfect, I just hear this noise.Could this be a cracked flex plate or something between the engine and trans? It would seem like it could be a mount but i'm 90% sure it's not a mount because I can hear the noise under the valve cover.It has made the same knocking noise before and after I adjusted the valve clearance. I did not notice anything unusual while I had the valve cover off. I also have been running 89 octane fuel and today I filled up with 92 octane just to rule out that possibility.

If anyone has ever had a cracked flexplate, could you please chime in and describe the noise you had? I would greatly appreciate it. Thank you.

 

You might just need a valve adjustment

oh sorry didn't read whole paragraph...

 

I dont know exactly wht it could be, but just one peice of info that might help, how many miles does it have?

 

it just turned 119000 miles. it has been maintained too. i just changed the oil with 5w30 as recommended.

 

i believe my valves need to be adjusted.

when my civic is cold and i start her up, i get this rattle nosie coming from in the motor. after she warms up, she is fine.

i probably wont do it until i do the timing belt next spring since i will have the cover off.

 

You can inspect part of the flexplate easily by removing the access cover on the bottom. Can't see the whole thing of course but if it happens to be cracked near one of the torque converter bolts it's obviously bad.

 

haha that's a different story. we've tried that a couple times and there's this support in the way. the thing is, you can't get it off unless you take down the exhaust. and you can't take down the exhause because a 13mm socket is to small and a 14mm is too big so we have to use a english socket and then itjust strips. but I can get the plate back a little bit without going through all that crap and I don't see anything obviously wrong, but I can't see that much. does honda use a 13.5mmnut for some reason? also, one of the nutshas a piece of crud or a flare on the stud and it won't come off. so where can I get another nut if I ever have to cut it, can I get it at autozone in one of those help! packets?

 

Exhaust nuts are often hopelessly rusted. They're 14mm when new but rust down to unusual sizes. Use a 6-point socket and choose whichever one, english or metric, that fits best. If you're ever able to apply enough torque to the nut, the stud with nut still rusted in place will usually unscrew from the manifold. Then you'd install a new stud and nut.