Why is it so loud

[jasoneschete]

We all know how loud our diesels are under the hood. What I was wondering
is exactly what component under the hood is making all the noise? Is it the injector pump, valve train or what? And knowing what it is, how can I quiet this beast a little. Its not comming from the exhaust just under the hood.

[cdnsarguy]

Most of the noise is the compression knock of a diesel.......

[CDX825]

Synthetic oil quiets them down quite a bit.

[big99diesel]

Lucas Engine Stop Leak Or Oil Stabilizer Will Quiet It Down.

[1dieselman]

Do you still have the insulation attached under the hood. If not maybe some hush mat glued in its place might help.

[rmr]

Mine used to be really loud until I had the IP timed.
It was to far advanced and now it's way quieter, smoother running. When it's warmed up anyway

[1987IDI]

I've always been told its a mix between the high compression combustion of diesel and the injector pump/mechanical injectors.

[jasoneschete]

Thanks for the info everyone. Right now she is in a few pieces but should have her back together in a few weeks. I'm painting the accessories under the hood so I cant crank her up yet. I will try the synthetic oil and lucas engine stop leak. I added a hood insulator mat but didn't run her yet. Also how do I check the timing on her I have an old timing light but I never used it. I was also wondering If I should remove the exhaust manifold and clean it out. I work on Detroit diesels at my job and I had one's exhaust manifold caked with 1/4 inch of crud

[1dieselman]

You need the feret adapter to use a timing light. There should be no reason to clean out the exhaust manifolds on this as opposed to a detroit especially a two cycle that has spent to much time idling.