4AG head bolts - crack crack

[Grega]

Putting my 4AG together.
Got my new head bolts out - lubed up, popped em in

29NM first cut
90 degrees second cut
then 90 degrees again (final)

One of the bolts really gave me a hard time - it was giving me some major cracking noises as I tightened it up. I mean MAJOR crack crack noises.

as these are torque to yield - this normal? never done this before....
i've heard em crack and groan coming out...

tks

[WDE_BDY]

Definitely nothing sitting in the bottom of the threads?

[EVOSTi]

did you chase the threads when you had the bolts out?

the sound you were hearing was probably the bolt threads binding in the block, or the underside of the bolt head binding on the cylinder head.

i believe they arent TTY.

[oldcorollas]

as above. chase otu threads.. make sure you aren7t getting hydro lock at bottom of threads, and make sure head has oil under it ans surfaces are clean.

can you tell if the crack is coming from the head or from the thread? (ie, does bolt head move easily and then the threads crack to catch up?)

[clubagreenie]

I'd be pulling them and giving it a good clean out down the holes, getting some new bolts (studs?) and trying a new tension wrench.

[Grega]

thanks guys for the info.
i'm going to pull it, and get some ARP head studs and re-chase the threads.
the more i think about it the less happy i am with it.

stu - coming from the the thread matey - definately.
evo - threads were chased - all clean (cleanliness is mandatory doing builds)
callum - definately not - blasted with air compressor to ensure clean
clubagreenie - as above. ARP head studs FTW.

[allencr]

evo - threads were chased - all clean (cleanliness is mandatory doing builds)
callum - definately not - blasted with air compressor to ensure clean

A real thread chaser or a tap?
Were they checked/tried out after the chase & clean?
What lube and what areas/spots were lubed?

'snap crackle & pop' from exhaust system, wheel & other stuff that were nasty, is my only experience IIRC.

[Grega]

allencr ; a tap
and no i didn't check them post tapping - cleaned with carb cleaner and compressed air
i lubed the threads, under the washer and under the head bolt

agree. its not normal. its all coming off - i bought a set of ARP head studs anyway.

[feral4mr2]

could of been the head bolt binding with the washer, if kinda dry it can make a noise like that as tensioned.

[oldeskewltoy]

Are the washers under the bolts?????

[clubagreenie]

Usually, though I tried to over bolt conversion once to make it easier to change.

[feral4mr2]

Are the washers under the bolts?????

there are washers that go under the head bolts indeed.

i've had them make a creaking crack sound when they have binded a little together upon tensioning. i had the thread lubed, but not the head of the bolt and washer.

[merc-blue]

I have seen this happen once, was quite a fair crack,

Did you have the right size head gasket??
i ave seen a STD bore HG on a overbored block it popped the sleeves out of the block.

Did you have the timing right?

[Grega]

ok
head is off again and bolts out
threads were in fact still dirty.
i removed the head in the order as stipulated by the bible ; and; to my suprise, doing 90 degree on most of the bolts actually had some at a point where they were ready to come out and others were still holding fast, meaning the that 90 + 90 hadn't quite worked out due to the crack crack crack gig
anyway long story short - ARP head studs going in.

many thanks to all those folks in the know and who have done this before - once again i have learned from experience and am forever in your debt. many thanks.

[allencr]

It's really difficult to use a tap to clean threads without removing metal because it wants to start cutting anywhere it can, and the usual trick of turning it backwards to find the starting thread is tough to do. I thought it would be easy to find a site with some background about NOT using a tap(starting/taper/bottom/plug/whatever) but a purpose made thread chaser, because of how easy it is to damage the threads & block, and wasn't able to find a decent one. It has to be out there!
A proper chaser will remove dirt & straighten out threads without removing much, if any, metal. I've never used one, just a wire brush and maybe a bolt with a notch filed in it, is fine for me.

Was the debris from each hole sparkly with lots of metal bits?

[Grega]

Was the debris from each hole sparkly with lots of metal bits?

no actually.
more like a brown dusty kinda stuff (and a wee bit of oil in one)

i asked the guy at the tool shop for a chaser and he didn't seem to know what i was on about....or didn't have them in stock.

i re-ran the m10x1.25 tap down the holes and it only wanted to "cut" when it got to the bottom of the hole. however in saying this, when i re-ran it again - it moved down the entire length of the thread very easily the 2nd time round. i'll jet some more carb cleaner down the holes and air comp it out me thinks again before putting the ARP studs in.

[nick.parker]

When undoing the head bolts on my 4AGZE (on two occassions) they all go CRACK when they initially move after proving the necessary torque to start undoing them. I'm always paranoid my 3/8" socket / extension are going to shatter in my face or something. I wear safety glasses!

Nick.