so after replacing the head and futzing endlessly with the timing chain, i finally got her running. went in to do a valve lash adjust after ~600 miles on the new cam and discovered my cam chain was quite slack. while rotating the cam by the bosses i felt it turn a few degrees as the slack picked up in each direction.

when i replaced the head, the chain was super tight - so much so that i had to lever the cam sprocket on with a big wrench. it seemed too tight to me, but everything i read stated "zero slack" and that's what it was. the first startup turned over verrrry slowly for a few revolutions, then something clicked and the engine spun free and started. i figured the tensioner was clicking into position or seating itself after being displaced.

alarmed by the amount of slack i was now seeing, i got my little endoscope cam out and went into the abyss to see what the chain tensioner was doing, and i found it was.... completely missing!!! looks like it got sucked into the hole and i have no idea what to do now. oddly, i couldn't see any parts lying around down there, but they could be hidden in a cavity that i can't see.

the engine runs pretty well (not perfect, hence my valve check) and doesn't make any crazy noise like i would expect from a loose chain, but i am concerned to say the least. anyone experience this chain tensioner vanishing act??

a couple videos of the slack chain:

going in to look for the tensioner:

nothing there:

just a whole where the oil comes out:

am i reading these pics correctly? is the tensioner really rattling around in the bottom end? perhaps this might explain slightly lower oil pressure?

Edited August 22, 201410 yr by rossiz

Nice result.

Excellent. Glad you got it back together and that the tensioner didn't take out any other parts when it snapped.

when i replaced the head, the chain was super tight - so much so that i had to lever the cam sprocket on with a big wrench. it seemed too tight to me, but everything i read stated "zero slack" and that's what it was. the first startup turned over verrrry slowly for a few revolutions, then something clicked and the engine spun free and started. i figured the tensioner was clicking into position or seating itself after being displaced.

Your tensioner clicked into position all right. Into position at the bottom of the front cover that is!!

Impossible to go back at this time, but I wonder what happened. You think you didn't get the tensioner plunger into position correctly at the very beginning? My guess is that it slipped out and was wedged on an angle from the very beginning and that's why you had such a hard time getting the cam chain on. And it went from there.

I liked your shot holding the distributor drive shaft from the top. I did the same thing when I was changing my oil pump and didn't want to mess with the timing. Looked like this:

yes cap'n, i believe you are right - it was out of the housing and at an angle, i'm guessing the "click" was when the head sheared off the plunger and the pieces fell down into the bottom. the two things that blow my mind are that the pieces never made any trouble with all the other moving parts in the immediate vicinity, and that the engine ran for 600+ miles with no tensioner whatsoever without skipping a tooth. i'll call it a great deal of luck!!

the other side benefit from this whole exercise is that i've now rebuilt most of the engine - all that's left is the block

rossiz, you were able to "wiggle" the oil pan free but was there a struggle re-installing? What did you use for gasket and sealant?

the pan wiggled out quite easily, went back in with no drama. i bought the gasket from msa - they had two versions, i bought the more expensive one which they told me is a bit thicker... it's a green gasket material - neither cork nor rubber, installed with no sealant. seems to work just fine (no leaks yet!)

Nice write-up and pix. Thanks for taking the time (during and after). It's good to see that the cautions about 'jack-up-the-engine-and-remove-the-oil-pickup' were unnecessary. I'm curious to hear more details about two components of the work that you say much about (and which have earned commentary in write-ups by others):

1. What tool(s) and procedures did you use to loosen harmonic balancer securing bolt? Degree-of-difficulty rating? Did you just put the car in gear rely on wheel chocks to keep the crank stationary, or did you remove the starter and wedge the flywheel ring gear?

2. Any drama in loosening the 3 long bolts that secure the water pump & timing cover (esp. the skinny 10mm bolt located at the 11:00 position on the pump body)? Tips/techniques... or did they all give up without a fight?

very cool, I forgot about the competition oil pan gasket from MSA.

the two things that blow my mind are that the pieces never made any trouble with all the other moving parts in the immediate vicinity, and that the engine ran for 600+ miles with no tensioner whatsoever without skipping a tooth.

Agreed... It's simply astounding that you didn't jump a tooth or run a chunky bit through the chain.

Murphy must have been off doing something else. You might want to watch your back.

2. Any drama in loosening the 3 long bolts that secure the water pump & timing cover (esp. the skinny 10mm bolt located at the 11:00 position on the pump body)? Tips/techniques... or did they all give up without a fight?

Those water pump bolts are notorious for rusting and breaking. Soak them for days with a combo of ATF/Acetone and you might get lucky. I only broke one when I did my water pump.

1. What tool(s) and procedures did you use to loosen harmonic balancer securing bolt? Degree-of-difficulty rating? Did you just put the car in gear rely on wheel chocks to keep the crank stationary, or did you remove the starter and wedge the flywheel ring gear?

thanks for the kind words - always fun to give back a little, especially with all the help this forum has given me. no special tools - i took off the oil pan first, then simply wedged a block of wood between the crank and the side of the block and used an 18" breaker bar to loosen the pulley bolt. it gave in pretty easily, no drama. getting the pully off was a pain, primarily because the two threaded holes for the puller were filled with crud and i couldn't get them clean enough to get the puller bolts in, so i made a Rube Goldberg by putting nuts and large washers on 3 bolts and wrapping the whole mess in bailing wire to grab the outside of the pulley (i guess it would properly be called the "pullee" in this case). fortunately it wasn't suck on too bad and came off with little fuss.

2. Any drama in loosening the 3 long bolts that secure the water pump & timing cover (esp. the skinny 10mm bolt located at the 11:00 position on the pump body)? Tips/techniques... or did they all give up without a fight?

HA!! drama for sure. i had already broken one of the long bolts when replacing the water pump and had drilled & re-tapped it all the way through the timing cover a while back (i left the water pump on the timing cover for this whole exercise - why create a leak, eh?) and fortunately none of the other long bolts broke. i did replace them all and chased all the threads clean with a tap. the heater hose connector bolt to the timing cover broke and had to be drilled out, i replaced both of those with some leftover manifold studs i had laying around.

You got a lot done in a short time. Impressive. I like the bailing wire puller trick, I did similar with an adjustable pipe clamp on a two jaw puller, to break a bearing loose and pull it. I think I took a picture for the record just because it looked so bad.

Found it...

Hey mate

I do have one question. For my understanding the tensioner is not supposed to have ANY slack during the first install. Looking at your picture with the chain I can see there's a bit of room there. Was this the way you finally installed it? Am I wrong here guys?

Thanks

Jan