Loud knocking sound

[californiajeepin]

1042956

So I'm checking fluids and whatnot on the jeep last night and while the motor's running

I hear this loud knock coming from the engine bay. Using the old screwdriver method

I pinpointed the noise to the distrubitor. I took the cap off and everything looked semi-normal except for some corrosion on the pole ends inside. I cleaned off the corrosion and put it back together and it was still doing it. In the manual it says some spark ping at idle speeds is normal but not at higher speed, and true to the manual, I can't hear the knocking at higher rpm's. But I don't know, I'm wondering if this is a common noise the 4 Litre motor in the YJ makes. Sure enough this morning, it wasn't doing it all so I'm completely confused and super paranoid. Soon I'll be wearing tinfoil on my head and whatnot.... Anybody have any thoughts on this?[addsig]

 

[PerformanceTruck&Auto]

1042968

If it is a timing knock/ping, try using a better grade of gas and if that still doesn't get rid of it, try retarding the timing a degree or two. It's strange though that you pinpointed it to the distributor area.... Maybe the distributor gear is worn and has some slop allowing it to knock around. HTH[addsig]

 

[PerformanceTruck&Auto]

1042969

That reminds me..... For you guys who have the Mopar MPI kit installed on your 258 engines, here's a tip.... If you're tired of having to buy 94 octane just so the motor doesn't ping under load, try installing spacer bushings between the crank sensor bracket and the oil pan.



Since the timing cannot be adjusted in the traditional manner (computer controls the timing), the spacers lower the position of the crankshaft position sensor in relation to the embedded magnet on the harmonic balancer which in turn retards the timing. Every 1/4" of spacers retards the timing approximately 4 degrees. Using this method, you can buy 89 octane without having to worry about pinging. HTH[addsig]

 

[Tug-n-pull]

1042977

I am not all that sure what to make of the knock but I have been wearing tinfoil on my head for days over my clutch problem and it really seem to help. LOL Tug.

[addsig]

 

[dave_denn]

I never thought of the tin foil idea. I am going to try that out tomorrow when I hear the clunk from my CJ...

Dave :roll:

 

[Sine Deviance]

You necro'd a 7-year-old thread. Just figured I'd tell you. Don't forget to check those post dates!

 

[dave_denn]

Yep,

You are right about the old thread reply. It was late (at least for me) and I didn't notice the posting date. I will be more careful in the future.

Dave

 

[carnuck]

The one time I forgot my tin foil hat I rolled my '73 J4000 due to a horse in the middle of the road!

 

[Gennybro]

I put my tin foil on, and I hear the voices,and they dont like hummer.