KA24de rattling noise, RPM and load dependant

[q-tip]

heres the deal with the ka24de rattling noise. they all do it. its the timing chain, usually the guide, you can replace it but its wont last more the about 5000 miles till it starts to rattle again, so i just live with it.

[goatee]

What did you ever find out?

[five&dime]

My dad had a very similar problem in his L28. He rebuilt the motor 3 times. Turned out it was the washer on the crank bolt that brought the pulley and damper to the crank. The washer was slightly incorrect which was causing the bolt to bottom out in the crank just a fraction of a milimeter before it snugged the damper and pulley. This was causing a slight rock in all the components. Was most audible b/t 2-3k and especially when coming off revs. The sound was also most audible in the lower front end obviously. Sounded like chain noise

Not saying this is your problem by any means but odd that the symptoms are very similar.

[goatee]

Holy smokes I'd have never figured that out.

[five&dime]

he spent 6 months stressing. He re-built the motor 3 times. And spent countless hours and $ on it. The worst part is that he has 4 S30's and was going to drop in the other 2 motors (all with same parts) in 2 of the other cars. Which would have damn near killed him if they all did it. he probably would have just sent them all to the crusher and started buying his other dream cars

He talked with everyone in the country who specializes in Datsuns and no one had a clue. He finally figured it out when talking to Todd at Tidewater Z and Riley at Lynchburg Nissan. He had bought the motorsports bolt and washer but didn't know it was slightly different from stock. The weirdest thing is that no one else ever experienced it before. I bet there are plenty of people out there stumped by their noise problem. Not realizing it is all b/c of a $1 washer!!!!!!!

He just drove the car for the first time in almost a year with no noise this past saturday. He was as happy as I have seen him

[goatee]

lol awesome, great story!

[duke]

Well, I wish I could say that I figured out what was wrong, but the motor went downhill before I could solve the problem. The #1 rod bearing spun, so it all had to come apart. While the motor was apart I did find some interesting things. All of the rod bearings didn't look very good, so it may have possibly been a rod bearing going south. Also, it looks like the valve seals were bad, as the combustion chambers were caked with carbon buildup. Another possibility was that the carbon buildup was causing the detonation. I should be starting the motor again within the week, so I should have a better idea of what the problem was soon.

[goatee]

Oh sorry to hear that! Well I'm sure it will come back bigger and better!

[five&dime]

At least now you will have piece of mind knowing everything was done right and done by you

[okayfine]

At least now you will have piece of mind knowing everything was done right and done by you

Not to be a Debbie Downer, but so did your dad

The more you move away from stock configuration, the more stuff like this happens. Just part of the game.