Hey everyone, I'm in the middle of a head gasket project and ran into a couple potentially scary issues while installing the head today. A little background: My car had coolant going into the combustion chamber & vise-versa, causing cylinder 2 to misfire on startup. When I picked up the head from the machine shop, they confirmed that the head was in fact warped around cylinder 2. They resurfaced it flat, did a valve job, all is good.

So then, skip to this morning. I get the head on, insert the new head bolts with oiled threads, tighten them in sequence to 30 ft lbs & start the sequence of additional 90 degree turns. Bolts 1-4 were fine, I get to bolt #5, toward the back of the head in between cylinders 1 & 2. I was using an angle torque meter to keep track of how far the bolt had turned. I got the bolt to about 60 degrees & all of a sudden it felt like the bolt lost tension, as in it were starting to strip or the head was breaking off. Well, ****, I thought. So, I finished tightening the rest of the bolts to their full 90 degrees without issue. I went back to bolt #5 & starting from the 60 degree mark, continued to tighten to about 85 degrees then stopped because it felt exceedingly hard to turn, not what I was expecting.

So then, I have a few questions -

-First of all, does ANYONE have an approximate torque spec for a fully torqued bolt? Something like "If the head bolt measures at at least xx ft/lbs, it's probably good"
-When exactly do these bolts stretch? During the final tightening sequence or over time with heat? Could I just back that bolt out (out of sequence), inspect it & re-try it?

-If the bolt has already been stretched, can I try replacing it with a new bolt out of sequence? Will I be putting the level-ness of the head in jeopardy by completely removing one of the bolts?

-I'm certainly regretting not opting for the ARP head studs at this point, would it be possible to install them, 1 by 1, re-torquing as I go with the head installed?


And now, the second issue! Forging ahead, I installed the chain guides and cam gear. While tightening the cam bolt, I heard a plastic crack and saw a little piece of plastic fall down into the timing chain cavity, probably landing in the oil pan. Upon closer inspection, I realized it was because the chain itself was not fully seated into the firewall-side guide, twisting it as the chain tightened & broke off one of the tiny little clips on top of the guide. So then, the piece of plastic is only about 1/8" in either direction. I drained the oil & it did not come out.

-Is this something worth pulling the oil pan for?

-Will it eventually just get sucked up into the filter & I can take it out that way?

-Does a piece that small pose any real danger to the engine? I hear about people's timing guides breaking apart all the time, much worse than this.

Sorry for the incredibly long post, would love anyone's input on this!!

 

I've had a few heads on and off. It would not alarm me to replace the bolts one by one with ARP studs. Why do you want to keep the head on? It seems like you should clean and chase the threads in that hole (ARP makes good thread chasers, too, they are not the same as a tap) which would require pulling the head.

Have you removed the front cover? It is worth checking and/or replacing the oil pump anyway (it's built into the front cover) and that would give you access to poke around in the oil pan for the broken plastic. The oil pump does have a strainer with small holes, so it is likely to stay in the pan - the worst case is it getting jammed into a crank or conn. rod bearing. But, this is a gamble.