2007-03-10 09:42:56 · 8 answers · asked by B-RO 2 in Cars & Transportation ➔ Maintenance & Repairs
It DOES matter when loosening the head bolts. You are able to warp the head just as much as improperly tightening them. The usual pattern is from the middle bolts to the outer bolts going in a circular pattern.
ex: On a straight six engine it would be the Right side bolt between number 3 and 4 cylinders then the Left side bolt, then the Left side bolt between number 4 and 5 cylinders then the Right side bolt, then the Right side bolt between number 2 and 3 cylinders then the Left side bolt, and so on. Pay close attention to the Rights and Lefts in the explanation. Also when untightening head bolts loosen each bolt only One Half Turn at a time, it's a multiple stage process.
I'm not sure if this made sense or not; if there's a way to post a picture I will. Is there a way?
This pattern isn't always the way to do it though, sometimes it is reversed so it would be the outside bolts to the inside bolts. The best thing you could possibly do is check a service manual specifically for your car.
2007-03-13 14:25:08 · answer #1 · answered by Anonymous · 0⤊ 0⤋
I really don't think it matters how u take them off.. When bolting the heads down there is a pattern and torque to prevent damage to the gasket and over torquing the bolts; but, seeing your now worried with damage to gasket in disassemble that really does not pretend; However, if you want to be on the safe side you can go to Auto Zone web page and key up automotive repairs, enter your vehicle make and other identification information and it will tell you what the pattern is for bolting the heads..
2007-03-10 17:55:31 · answer #2 · answered by denfasr 4 · 1⤊ 0⤋
Just loosen them a little at a time in whatever pattern you want. It wouldn't be good to have one bolt all the way tight when the rest of them are out, but it's not critical like it is when your smashing the gasket down.
2007-03-10 18:24:48 · answer #3 · answered by Nomadd 7 · 1⤊ 0⤋
If you are talking cast heads, cast block, it doesn't really matter much. If you are talking aluminum heads, most have a removal sequence. The sequence is usually the reverse of the tightening sequence. Heads can warp by using improper removal techniques! Also, never tear down a hot engine (gotta be overnight cold) if you plan on putting it back together. Check tobe sure you can re-use the old head bolts, and also run a thread chaser in the holes.
2007-03-10 18:42:18 · answer #4 · answered by br549 7 · 1⤊ 0⤋
It doesn't make any difference unloosening the bolts, only when tightening the bolts you have a pattern to follow.
2007-03-10 20:25:43 · answer #5 · answered by mister ss 7 · 0⤊ 0⤋
you only use a bolt pattern when tightening them to keep head from warping
2007-03-10 17:49:23 · answer #6 · answered by Howdy 2 · 2⤊ 0⤋
Loosening does not matter.
2007-03-10 17:46:18 · answer #7 · answered by Anonymous · 1⤊ 0⤋
Agree with the above, both.
2007-03-10 17:51:40 · answer #8 · answered by occluderx 4 · 1⤊ 0⤋