IHEARTLS1

iTrader: (1)

leaking coolant out of cylinder #7 right after driving the car, engine hot. i saw some antifreeze dripping and saw a trail right under the header tube. the cylinder holds pressure fine with the valves closed. i think it's either the head gasket or the studs. i did not use any sealant on the studs that go into the block. my plan was to pull each stud out one at a time, seal it up then put it back, tighten down and add 5 ft lbs. anyone have a similar problem? i used gm .051 mls gaskets with no copper spray.

IHEARTLS1

iTrader: (1)

i just read this out of the manual:

Apply a 5 mm (0.20 in) band of threadlock GM P/N
12345382 or equivalent to the threads of the M8
cylinder head bolts. Refer to Sealers, Adhesives and
Lubricants.

RPOWU8

iTrader: (13)

The holes in the block do not go into the water jackets. Putting sealer on the studs is not required.

A retorque might help but you might just need to add some alumaseal or bars leak to seal it up. Just use half a tube of the dry stuff and drive it around a little and it will probably seal right up.

DJ

IHEARTLS1

iTrader: (1)

i will not band aid the problem with "mechanic in a can". this engine will be used for competition.

SUCK MY SS

iTrader: (14)

is this a new engine?
if so, the studs need to be torqued and loosened 3 times before final torquing, in order to align the stud...
some say, even need to be retorqued after a few heat cycles..
if you have not done that, i would start there..
also, what are you torquing them to? and what ar you using on the threads for lubrication?

IHEARTLS1

iTrader: (1)

it is a junkyard engine with 11k on it. it is new in the sense that i just installed the studs, heads, etc. i torqued the studs to arp's spec, which i think was 25 ft lbs on the small studs and 75 on the others. i used arp's lube on the threads that bolt the heads down, i put NOTHING on the threads that go into the block.

SUCK MY SS

iTrader: (14)

you dont need to put anything on the stud threads going into the block...it is a blind tapped hole...there is no passage to water jacket...
how did you install the studs into the block? they are only suppossed to go in hand tight...if you torque em in there you will crack the block...
how did you clean the deckof the shortblock? did you straight edge it to see if it was in spec?
you never know what your really getting at ajunkyard, ya know...

did you also put lube on both sides of the washer? and install the washer w/ the inside chamfer facing up?

IHEARTLS1

iTrader: (1)

i think the leak is coming from the header bolts. i pulled the header off and the threads are wet with antifreeze. the bolts were brand new and bone dry when i put them in. i'm going to grab a pressure tester and see if i can put pressure in the system if it leaks out the bolt holes in the head.

IHEARTLS1

iTrader: (1)

confirmed as the header bolts leaking. sealing them now.

1quickirocz

were the header bolts too long or something?? bottomed out in the head and cracked maybe?? The reason i say that is because the bolts that came with my headers for my swap were WAY too long. Im having to use stock manifold bolts.

IHEARTLS1

iTrader: (1)

no it looks like water runs through them. the stock bolts had teflon on them, i should have put it on as a precaution.

1quickirocz

Hmmmm.......maybe my heads are different then. Im running 799s and my header bolts deff bottom out in the bolt hole before they tighten down on the header flange.

RPOWU8

iTrader: (13)

Hey just trying to help. With the MLS gaskets you basically have a metal seal between the head and block. Sometimes you will have a little leakage under the gasket. Thats why some people spray the gaskets before they assemble them.

Anyway sounds like you have your answer above. The exhaust port bolt holes should be blind also.

Good luck with your project.

DJ

IHEARTLS1

iTrader: (1)

the head gasket wasnt leaking, it was the header bolts. i used sealant and the problem is done. 823 heads. rectangle port, not cathedral.

RPOWU8

iTrader: (13)

Sorry, I meant the post above, not what i said in the paragraph above what i wrote. I understand it was not the head gasket.


I had issues with exhaust manifold bolts on my 823 heads. They would bottom out in the hole about the same time they touched the header flange. I had to buy shorter bolts. I think I will pull them out and see if I have any issues as well.

Good catch.

Thanks,

DJ