Cylinder head bolts - to replace or leave alone (rusted bolt head)

[muncedog]

So I noticed in my general maintenance that there is some surface rust on the heads of some of the cylinder head bolts. Motor running sweet and is 17 years old....
For now I have degreased/cleaned and applied Johnson anti corrosion (waxy) spray.... Looks like they originally have some black paint on the surface.

I am contemplating removing/replacing them before they get worse... However I am aware of if it ain't broke don't fix it as they may shear etc. Also new official bolts are very pricey particularly as I'm importing to NZ.... Not sure what material they are...

Any thoughts/experiences good/bad?

 

[Vic.S]

Surface rust on the bolt heads is no problem.
Motor running sweetly
Definitely a case of " If it aint broke dont fix it!"

 

[Chris1956]

There are usually grade markings on the bolt heads. A series of raised "tic"marks for grade 5 or 8. Replacement bolts should be avail (if you have SAE bolts) in your country, if you just match them up. However, I agree with Vic. If it ain't broke....

 

[boobie]

Sleeping dogs should be left to lie !!!!!!

 

[Flukinicehole]

Do you see any indication of leakage around the head? If not then leave it be.

 

[racerone]

There is nothing " special " about those bolts.----As far as the pricing of fasteners goes it is due to the fact that storage / recall / packaging / shipping of a single small item is expensive.---Nobody makes any money selling a single bolt .-------Need some , than most dealers have a bin full of good used ones for next to nothing.

 

[thunder550]

Don't mess with the head bolts unless you are planning to pull the heads and replace the head gaskets. The bolts need to be torqued a certain way so the gaskets seal properly. I would not be comfortable pulling and replacing them one at a time.

 

[jakedaawg]

Just an fyi, it may or may not apply---

Not all grade 5 or grade 8 cap screws are the same. There can be a difference in whether or not the threads are "cut" or "rolled". Many times head fasteners are made from rolled threads as these are generally considered superior under tension than cut threads which are less expensive. Rolled threads are easily identified as the threads are raised above the circumference of the shaft where cut threads are the same diameter at thread and shaft.