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Car: 2010 Passat CC 1.8 TSI

Would it be a really big problem if I use the old cylinder head bolts or not?

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    @Criggie I did reference that post in my answer...
    – Solar Mike
    Jul 25, 2017 at 19:37

4 Answers 4

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Your Passat uses torque to yield bolts, so they must be replaced. The torque to yield bolts are considered "one and done". This is because during the torquing process, they are stretched beyond deformation, past their plasticity. If you try to use them again, they will fail. If you reuse them, not only will they fail, but you will most likely cause damage to the head due to warpage.

Do it right and get new head bolts.

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  • Agree. In the grand scheme of things, new head bolts are a tiny fraction of the cost of the work involved.
    – PeteCon
    Jul 25, 2017 at 4:43
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Replace the bolts, this has been covered in detail on this site : here is one such post with lots of detail :

"Always Replace" (torque-to-yield) Bolts

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short term "no". long term "yes!". Why take the chance. Just replace them to make sure your torque is right so you don't have any problems in the future. The old ones will not torque correctly.

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I once had to remove and grind the head of an Audi 4 cylinder ,overhead cam . Audi said I must use new head-bolts; but I used the old ones and it worked fine.

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    Not good practice - some people do this as a cheap repair just to sell the car on....
    – Solar Mike
    Jul 25, 2017 at 4:42
  • Its likely your former car had a shortened lifespan because of this repair.
    – Criggie
    Jul 25, 2017 at 8:02
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    This is why people have a nightmare when they buy used cars. Cheap/incompetent mechanics and cheap owners are the key. Jul 25, 2017 at 8:54
  • I took off a couple of cylinder heads when I used to repair my own car. As an amateur mechanic, it took a weekend to get the head out (after unbolting everything to get it free), and another weekend to refit everything. Having the head skimmed cost me a bit, and a new head gasket and exhaust manifold gasket cost a bit more. With all that time and money already gone into it, skimping on the cost of head bolts can only be attributed to incompetence, carelessness, or stupidity, or active malice if you're fixing the car to sell.
    – Graham
    Jul 25, 2017 at 9:50
  • Mind you - it's not only owners, there are cheap incompetent dealers / garages as well...
    – Solar Mike
    Jul 25, 2017 at 12:01

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