JX Diesel rattle on tip in, NOT fuel or injector related

[unitedracing]

I just got my Vanagon on the road, complete with jx spec engne. I've only driven a few miles so far but have developed a strange sound. When revving slightly I get a strange rattle sound for a second that goes away. It sounds mechanical, not injector related. I'll be picking up a stethoscope today to try and find it but was wondering if you guys have any ideas. It almost seemed to be coming from the turbo area...but not exactly. Almost sounds like a tensioner bearing but I don't hear sound from that area...and the timing set is all new.

[fatmobile]

Rebuilt engine or used?

[unitedracing]

Rebuilt. It was a very low mileage engine, but I went through everything just to double check. It didn't start making the noise until I had about a hundred miles on it.

[fatmobile]

Did you change the rod bushings and have them reamed to fit the piston pins?

[unitedracing]

Did you change the rod bushings and have them reamed to fit the piston pins?

No. This engine was harvested from a wreck by a friend years ago. Not even 20K on it so I didn't touch those. All bearings were checked and I did replace the mains and big end bearings since I was in there. Really didn't have to, but I had the parts

[libbydiesel]

It might be helpful to post an audio recording or video. 

Does it have the metal or plastic timing cover?  Anything touching the exhaust?

[unitedracing]

Well guys. I found the issue. Thankfully an easy fix. The triangle shaped gravel guard right above the crank pulley was loose and would rub causing the noise. The bolt was tight, but a hair too long. I'm told many of these are missing on early engines with the metal belt guards

[ORCoaster]

I have to shake my head when I find stuff like that.  Yes the part is there, yes the bolt is there but they are just not in sync with one another.  I do repairs for people all the time and you should see some of the stacks of washers I have removed in place of using an inch or so shorter screw or bolt. 

I used to think the adage, Necessity is the Mother of Invention was what drove people to do stuff like that but I have learned that it is more about what is on hand that will still get the job done. 

I am not against people being creative but only to a point.