I have owned my mk1 caddy for 4 years now and have done a huge amount of work and modifications. The block is the original 1.6d with a 12mm head, it was re-ringed and the rod bearings were replaced 8k ago. Currently I am running a K03 from a TDi with an aaz intake and exhaust manifold, modified mk3 2.5" downpipe, a 1.6td pump and 1.6td injectors, an FMIC and an ACN 5spd trans swap.
Now, I have taken this engine apart a few times, replacing blown headgaskets due to the head being warped and now a new "known straight" 12mm head with original material HG. I run an EGT, Boost and Oil pressure gauge to keep my mind at ease.
3 nights ago I was driving on the highway at 65mph cruising along just fine, and then the engine started getting very shaky. There was so much vibration that the things in my glove box were hopping up and down where before they were not. The vibration came and went for a few miles and then the engine started getting VERY loud, a DB meter measured 102 decibels. Along with the scary loud noise came more vibration, so much so that it rattled my crank pulley bolts loose and kicked 3 of them out at speed on the road, 3/4 of my axle bolts were hand loose and one of my exhaust bolts started backing out. I learned all of this on the side of the road where I waited for tools and new bolts thinking that the noise and vibration were coming from the now wicked loose crank pulley, I got everything back tight and started it up again, same sound, less vibration. I limped the car back home the 5 remaining miles.
I was able to drive at 50mph with no problem, my boost gauge, egt and oil pressure gauges were all reading normal, I did not push hard at all so I can not say 100% that the power was all there. When I got home it was running fine, except for the noise. My first though was injectors, i knew my 1.6td injectors needed to be re-nozzled so I went to bed thinking that was the issue, just severely worn nozzles. I have a set of 1.6na running but 150xxx mile injectors that I swapped in for the time being just to test, same noise. It sounds just like it should except 4x as loud. Much more like an all fuel tractor than old VW.
I check my timing today and everything is legit. Cam, flywheel and pump are all where I left them. There is oil on the cam and when I rotate it by hand new oil gets pumped up. it starts up every time, just like normal from cold leading me to believe that the compression is good. The fuel in the system is only 6 weeks old.
Anyone have an idea? Would a dying pump cause a running driving engine to sound like it was fueled by demons? Serious valve clatter that get amplified under the valve cover?
i will try and get a video of it running tomorrow.