Knocking noise

[AkademikONE]

I was driving to LA the other day when it was raining and suddenly I felt something knocking from under my car. You could also feel it from under you. I slowed down and went to the nearest exit and pulled to a gas station. I was thinking my wheels were loose, so I tightened the lug nuts. Tight as can be. I went back on the freeway and it didn't do it anymore. I was going back home when it did it again. This time when it happened, it felt like I was losing power, I pressed the gas but the car didn't accelerate like it should. I again felt the knocking from beneath the car. It was scary. It never did this when it wasn't raining, only when it rains.

What's wrong??

It's a 96 s14 by the way.

[AkademikONE]

Anyone?

[steve s14]

is the engine overheating during the time when it is knocking and losing power?

[AkademikONE]

Nope, not at all. 3 other people on Zilvia experienced the same thing, in the rain too, but they can't explain what caused it.

[onosqv]

It's the Boogie Mannnnnnnn, hahaha, j/k.

I really don't know what's wrong. The closest I've got to weird knocking noises while driving is because my suspension is whacked. I have those adjustable camber arms and t/c rods that could never be greased because I couldn't find the fittings & I think my springs may not be sitting completely correctly.

Is your exhaust wiggily? Maybe the rain loosened up the hangars a bit, so it bangs against something.

Look on the bright side, rain's almost gone

[steve s14]

this is a guess, but worth a try, i'm guessing it might be a spark plug wire problem. get a spray bottle and fill it with water. then with the engine running, spray the wires and distributor cap area with a light mist of water, do not use a garden hose and spray gun. if you see some arcing and the engine starts to run rough, then that is most likely the problem. replace the spark plug wire set and possibly cap, rotor, and plugs if needed, i recommend oem, and test again.

[AkademikONE]

It's coming from underneath the car, not from the engine.

[steve s14]

without seeing the car it's hard to guess the problem but i was assuming you have an aftermarket exhaust and maybe when the engine misfires, the exhaust starts shaking and hits against the frame rail or something like that causing a knocking noise under damp conditions.

[ddgsxr504]

Do you have a header on your car? If so it may be knocking against the floor board caused by what Steve said, if the engine starts misfiring it would jerk and cause the knocking sound.

[AkademikONE]

Yea, I have Apexi N1 Duals. No header though, stock.