Realized I had been torquing cylinder head bolts all wrong for 8 years

So I was helping a buddy do a rebuild on an old 5.9 Cummins last month and he was nagging me about not following the sequence. I told him I always just do a crisscross pattern by feel and it's been fine. He pulled up the factory manual on his phone and showed me the exact order with torque specs and angle turns. I had been guessing on every single engine I've done. Has anyone else found out they were skipping a crucial step for years and never knew it?

3 comments

3 Comments

barbaraw472mo ago

My buddy Dave ran a small diesel shop for ten years and never torqued head bolts in sequence. He did a big 7.3 Powerstroke job and two months later the head gasket blew because the bolts weren't seated right. He had to eat the cost of a whole new gasket set and labor, learned the hard way just like you.

gavina732mo ago

Did your buddy ever figure out why he skipped that step for so long? I had a friend who ran a mobile mechanic van for years and thought he could eyeball valve clearance on old Chevy small blocks, til he wiped out a cam and had to buy the customer a whole new engine. It's funny how one shortcut can cost you way more than you ever saved, ain't it?

barbara_baker5725d ago

Hold up, is it really that serious though? I mean, I get torquing to spec but the sequence thing seems a bit overblown in some circles. I've worked on plenty of small block Ford 302s over the years and just cranked em down in a crisscross pattern, never had a blown gasket. Maybe Dave just got a bad batch of head bolts or the block surface was warped. Two months later is a long time to blame it on the bolt order.