What are the torque specs for timing chain replacement?

Tiny
RMARTINA
  • MEMBER
  • 2016 BUICK VERANO
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 110,000 MILES
Timing chain jumped timing on intake camshaft installing replacement head, and timing chain kit. Found head torque specs. Need torque specs for cam to head, VVT sprocket to camshaft and front cover bolts.
Wednesday, July 24th, 2024 AT 10:52 AM

6 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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This job must be done correctly to avoid bending intake or exhaust valves.

Camshaft Bearing Cap Bolts: Torque to 89 inch-pounds (10 Nm) in sequence head torque

Front Cover Bolts: Torque to 18 foot-pounds (25 Nm)

VVT Sprocket Bolts: First pass: 30nm or 22 ft pounds, final pass to an additional 100 degrees

Here is the correct way to change out the timing chain with guides and the chain tensioner as well. Check out the images (below). Let us know if you need anything else.
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Wednesday, July 24th, 2024 AT 4:26 PM
Tiny
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Ken L,

Just what in needed to finish the job, and do it correctly, before I got your reply, I put a torque wrench on the camshaft bearing cap bolts no movement until I passed 10 Foot Pounds, this was factory torque, but I guess it should be 7.4-foot pounds aka 89-inch pounds? Thank you for all the info.
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Sunday, July 28th, 2024 AT 11:43 AM
Tiny
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I'm considering lapping the valves or doing a valve job before I replace the head, engine has 120,000 miles on it and wasn't using oil. I haven't received the used replacement head, yet. The Head comes with valves, and springs in it
What would you recommend, and what is the valve spring installed height, just in case.
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Sunday, July 28th, 2024 AT 12:23 PM
Tiny
KEN L
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Correct 89-inch pounds. Is the head that is coming rebuilt or used? If it comes rebuilt, I would just check the valves which if you check out this video it will show you how.

https://youtu.be/p4krsFVguD0?si=TlErmf8DR0ZUo7Zt&t=475

If the head is used, I would have a valve job done. Here is how to remove the valve springs, they don't have an installation height. Check out the images (below). Let us know how it goes.
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Monday, July 29th, 2024 AT 9:34 AM
Tiny
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The head is used, spring tension on the seat, doesn't need correcting for valve depth, after a valve job, just reinstall the springs? I bought a set of new valves to install, so they should be closer to the original height after machining.
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Monday, July 29th, 2024 AT 1:39 PM
Tiny
KEN L
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If the height is the same as the old parts you should be okay to reassemble. You can call a machine shop for the specs, we don't have access to them.
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Tuesday, July 30th, 2024 AT 9:27 AM

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