Hey guys. I just had a shop rebuild my 4G63 block of my 90 TSi AWD. It was bored and crankshaft resurfaced. The shop assembled the block. I assembled the rest of the engine and put it back in the car. It ran well for the first 150 miles until I went to change the oil. I found a lot of metal filings in it. I pulled the engine apart and I am just wondering what you guys may think this contamination is from. I know that much of the metal is magnetic. I am going to have a licensed tech come over while I take apart the rod and crank bearings just as a witness before I go further. I have some pics here: Thanks guys.

Metal in oil - 4G63

Uh did you drove the car as soon as you installed the engine?

If so, your suppose to at LEAST change the oil twice or at least 3 times before heading out.

If not and taken the precaution above... thats a lot of shavings.

Ok. We can speculate all we want but it's worthless. Update this thread when you figure it out.

Good to get a licensed mechanic do that for you, for legal reasons. If we're still speculating, I'd say the best chances are that it's the bearings.

But definitely let us know what your break-in procedure was, and if you used pre-assembly lubricant on the internals.

Hey thanks for the info. I flushed the engine a number of times before taking it out (3 or 4 cant remember) with new filters each time. The oil was clean during that time. The small filings are from the bearings. The engine shop that machined the parts believes it to be caused by oil contamination from an external source (oil cooler or cylinder head) They did admit to me that they did not flush the oil galleys in the cylinder head even though I requested it. I did also have the oil cooler flushed at a shop. They stated that there was no sign of metal contamination in the cooler. I recently took the engine to another engine shop with a good reputation and explained it to them. They believe that the bearing failure may be the mistake of the 1st engine shop but he will not be able to look into it for a few weeks. The 1st shop cannot remember the build or whether they used assembly fluid on the bearings or not. The rod bearings showed signs of dry startup even though I primed and circulated the oil (ran the starter without fuel injection fuse) through the system like I was told and there was oil reaching the cylinder head. One rod bearing apparently also showed signs of incorrect ignition timing which was strange as the base timing was set to 5 BTDC. The break -in was done by turning the boost down. Running the car at different rpm ranges and running from about 30 MPH to 50 MPH then close the throttle and coast back down to 30 MPH. This was done about 10 times to load the piston rings and seat them.

If that's all you did to prime the motor after a build, then it was not sufficient. Most people spin the oil pump with a drill. I use an external fluid pump into the filter housing.
Just turning the starter will mean the bearings are dry for long enough to damage them.

I used an external pump to prime the oil pump then circulated by spinning the engine.