I'm putting a motor back together after a LONG rebuild. The motor overheated twice last summer, so that along with leaks galore prompted me to tear down the motor.

Putting everything back together- heads back on, new cam, lots of clean parts, and as I went to install the water pump, something rattled, something that hadn't rattled before. I dug it out with needle nose pliers, and it's big enough to read the part #mp3616 7. I assume that this was causing intermittent flow issues which in turn caused the motor to overheat. I'm curious where it came from, as its a portion of a part- my concern is that the rest of it will break loose. What I dug out is 3/8" tube, 1.25 inches long. Internet search brought up one other identical issue, also with a '99. Any thoughts?

 

I have a thread discussing this up now on this forum, its "waterpump swap post op question"

Seems to be that it may be a part of the rad that cracked free, mine was found just about to enter the waterpump.

 

Same place I found it, but I assumed the part was far to big to make it through the tstat, so it was part of an old tstat. Yours caused overheating as well? I will head over to your thread.