Replacing lower timing chain guides: an epic adventure
I was experiencing a rattle between 1200-1400 rpm. Pulled valve cover and diagnosed broken lower timing chain guide on the non-tensioner side. Bummer, but whatever. Order some parts, start the tear-down. All goes smooth until I get the timing cover off and see that the holes in the block that the mounting bolts thread into are stripped.
So I arm myself with some tools. 90 degree drill chuck, since there's no room in there. Several sizes of drill bits (19/64, 5/16, 21/64). I wanted to do this gradually, as to not risk snapping a bit off in the block, or destroying the hole. Finally, a thread repair insert kit. Brand is "V-Coil", but they're similar to heli-coil, etc. V-Coil is made in Germany, so can't go wrong, right?
Used and old t-shirt and some magnets to catch shavings. I then drilled out the holes, working my way from smallest to largest drill bit. I had to ghetto rig my tap handle to work around the crankshaft and head. Using the tap provided with the v-coil kit, I tapped the holes going slowly, using lots of lube, backing the tap out to clean it several times per hole.
Freshly tapped holes.
Threaded the v-coil inserts into newly tapped holes.
Dry fit the mouting bolts and chain guide. Plan on using red loctite on these bastards.
Here are the old guides. I broke the tensioner guide removing it. It was quite brittle, and I ended up gashing my knuckle on it (note blood in first picture). One of the mounting bolts is still in the oil pan. I'll try to fish it out with a magnet. If not, it will stay there until I get around to doing my oil pan gasket.