help! 7mge head stud replaced with 14mm bolt?? what the

[bosty]

I have a Cressida reconned motor, which was not torqued down.
went to overheat when I found coolant had escaped through overflow bottle.
thinking that BHG is starting and am trying to catch it before goes any further.


have rocker covers off loosened 3 head studs when I found like a 14mm bolt in the rear of the in side.

was going to try and retorque th head but cannot seem to get socket onto this.

Why would this be on a reconned motor???
apart from the fact a retard must have put it together..

[dnegative]

Stock 7M's dont use studs, they use regular old head bolts.

[Daddio]

As above, 7M use a 14mm double hex (12 point) head bolt. These are TTY (torque to yield) and generally should be replaced each time they head is removed. You'll need a deep reach, thin wall 14mm double hex socket to remove. Suggest replacing with ARP studs/washers/nuts (same size nuts as OEM) for around $150 from memory.

[allencr]

Stripped block & tapped to a larger size?
14mm? Thread diameter or the wrench size??????????????

This manual shows the early & incorrect head bolt torque. It also show that the bolts are not TTY & not a non-reusable/replacement item.
http://www.cygnusx1.net/Supra/Librar...aspx?S=EM&P=32

[andrew_mx83]

As above, 7M use a 14mm double hex (12 point) head bolt. These are TTY (torque to yield) and generally should be replaced each time they head is removed. You'll need a deep reach, thin wall 14mm double hex socket to remove. Suggest replacing with ARP studs/washers/nuts (same size nuts as OEM) for around $150 from memory.

Sorry mate but most of that is incorrect.

7m head bolts are a M12 x 1.25mm pitch with an internal hex 10mm head
You need a long 10mm hex key, not a socket
The bolts are not TTY and can be reused as long as the have not corroded, stretched or stripped
ARP bolts or studs are unnecessary on a 7m-ge unless you start to get silly with compression or rpm


To the OP -in what way is it a '14mm bolt'? 14mm thread or head? As above, it was possibly stripped and retapped if the thread is really M14.

14mm head on an M12 bolt is pretty unlikely, however there is one on the 7m, for the cam belt tensioner. I cant remember off hand if it's long enough to use as a headbolt though, but i think it is just a grade 4.8 bolt, so no good anyway.
I have stacks of stock used headbolts if you want me to send one.
I also have a video on the youtubes on how to retorque the bolts.

[bosty]

Sorry mate but most of that is incorrect.

7m head bolts are a M12 x 1.25mm pitch with an internal hex 10mm head
You need a long 10mm hex key, not a socket
The bolts are not TTY and can be reused as long as the have not corroded, stretched or stripped
ARP bolts or studs are unnecessary on a 7m-ge unless you start to get silly with compression or rpm


To the OP -in what way is it a '14mm bolt'? 14mm thread or head? As above, it was possibly stripped and retapped if the thread is really M14.

14mm head on an M12 bolt is pretty unlikely, however there is one on the 7m, for the cam belt tensioner. I cant remember off hand if it's long enough to use as a headbolt though, but i think it is just a grade 4.8 bolt, so no good anyway.
I have stacks of stock used headbolts if you want me to send one.
I also have a video on the youtubes on how to retorque the bolts.

thanks for your help and information.
yeah there is -13 x head bolts- the 10mm hex type
and -1 x 11/16 old school bolt(it has 1 embossed on top of it) this is at rear of inlet side.

Well, I managed to crack all the head bolts back in reverse order including the bolt at rear.

car was not driven left overnight before loosen then retensioned to 30 then 45 then 60 then to 70.
The 11/16 bolt in rear made it to 60 then at its turn to 70 I turned it 20degrees without torque wrench clicking. I got a bit worried here and decided to stop before damaging anything.

Am replacing cam covers today draining the oil and filter to avoid any contamination, oil refill and then starting to see if my luck has held out!
will respond soon and thankyou once again for your generous help
Regards
bosty

[Daddio]

Sorry mate but most of that is incorrect.

7m head bolts are a M12 x 1.25mm pitch with an internal hex 10mm head
You need a long 10mm hex key, not a socket
The bolts are not TTY and can be reused as long as the have not corroded, stretched or stripped
ARP bolts or studs are unnecessary on a 7m-ge unless you start to get silly with compression or rpm


To the OP -in what way is it a '14mm bolt'? 14mm thread or head? As above, it was possibly stripped and retapped if the thread is really M14.

14mm head on an M12 bolt is pretty unlikely, however there is one on the 7m, for the cam belt tensioner. I cant remember off hand if it's long enough to use as a headbolt though, but i think it is just a grade 4.8 bolt, so no good anyway.
I have stacks of stock used headbolts if you want me to send one.
I also have a video on the youtubes on how to retorque the bolts.

Perfectly correct! I mixed the ARP nuts with OEM bolts, and OEM ar 10mm hex drive. My appologies...its been a while since I did the build.
However, the OEM head bolts are TTY and should be checked for stretch if you are considering re-use. Most people (self included) would not re-use OEM head bolts.

[andrew_mx83]

The 11/16 bolt in rear made it to 60 then at its turn to 70 I turned it 20degrees without torque wrench clicking.

Now there's a bolt that has been torqued past its yield point.

You need to replace it, pm me your address and ill stick one in the post this afternoon. They almost always blow at the rear, you are asking for trouble by leaving it.
I also do an upgraded cam cover bolt set which wont keep coming loose like the stock ones do. The set is $22


FWIW, i reuse stock head bolts all the time, and i have put a *lot* of 7m heads on. They are not TTY.

[Daddio]

I guess to each their own Andrew...

[allencr]

Well, I managed to crack all the head bolts back in reverse order including the bolt at rear.

car was not driven left overnight before loosen then retensioned to 30 then 45 then 60 then to 70.
The 11/16 bolt in rear made it to 60 then at its turn to 70 I turned it 20degrees without torque wrench clicking. I got a bit worried here and decided to stop before damaging anything.

One at a time, one by one, not all at one time, right??

Just take out that bolt & look so you can quit calling bolts by their wrench size & know what's going on.
If it ain't stretched, sorry.
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Useless & done.

[Supra967]

FWIW, i reuse stock head bolts all the time, and i have put a *lot* of 7m heads on. They are not TTY.

tries to think of where I read about Toyota bolts... Pretty sure you'll find they are use once man.

[bosty]

No oil in pan.
.

I am about to remove plugs before turning over a couple of times.

then I will refit plugs and give it a go.

If it kicks over I am going to buy some new bolts or studs and replace them all, including the 17mm oddity.

then quickly sell the fecker

[andrew_mx83]

Hi bosty just hold off mate a new headbolt is in the mail, just replace that odd one and you should be sweet.

Im unclear on exactly how you retorqued the bolts, hopefully the gasket seal wasnt disturbed. Either way after what you found i'd be tempted to pull the head off, straight edge it (surface if necessary, hopefully not) and reinstall with a fresh OEM gasket, using your 13 headbolts and the 1 I sent you.
While its off you can drill the missing coolant hole in the head and make sure the block is upto scratch, then you should have years of happy and trouble free motoring.


We can debate whether the bolts are TTY all day, but the TSRM says they arent, and if they were then i would have had about a million HGs let go by now as i reuse them all the time.

[Daddio]

Hi bosty just hold off mate a new headbolt is in the mail, just replace that odd one and you should be sweet.

Im unclear on exactly how you retorqued the bolts, hopefully the gasket seal wasnt disturbed. Either way after what you found i'd be tempted to pull the head off, straight edge it (surface if necessary, hopefully not) and reinstall with a fresh OEM gasket, using your 13 headbolts and the 1 I sent you.
While its off you can drill the missing coolant hole in the head and make sure the block is upto scratch, then you should have years of happy and trouble free motoring.


We can debate whether the bolts are TTY all day, but the TSRM says they arent, and if they were then i would have had about a million HGs let go by now as i reuse them all the time.

Sound advice Andrew I would do the same (plus ARP studs since thats how I roll...but I fully appreciate others having different points of view )

[allencr]

Sincerely Doubt a stock bolt is gonna do it for him.
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OP, Please PULL out the fucking bolt & see what ya got!