Frost plug in head of 470????

[sdoomaha]

Loaned my 84 Cheetah with recently rebuilt 470 to a friend. I know I know....friends don't let friends drive 470s....but hey.

He is now out of town and tells me it is leaking "water" from a hole in the head on the exhaust manifold side all the way back. (There is no water circualting through the motor so I know it is antifreeze) Says he can also hear what he called a slight "exhaust leak" noise that goes away when he sticks his finger over the hole. Thought it was the head gasket going again...he assures me it is higher up on the head than that and it is a small hole that he guessed had a frost plug in it that released/fell out and is now leaking.

Impossible to diagnose/explain without seeing it....and the manual does not provide an exploded view of the head that would account for this mystery "hole."

Feel silly for asking...but anyone have a shot in the dark what he is referring to?

Thanks...and yes bring on the hi jinx...I deserve what I get.

 

[sdoomaha]

Re: Frost plug in head of 470????

He just called back....said there is nothing coming out of this "hole" except exhaust...said there is a "raised ring" right in the casting of the head with a hole the size of his finger in the center. No threads in the hole, but a small "lip" like is there that woudl stop a frost plug from going in too far.

Said it is not hindering the performance at all....but the escaping exhaust is fairly loud.

Hate to stop his trip short....but not being able to see it and diagnose it...hate to cause a problem since it is a fresh motor.

Any thoughts appreciated.

 

[stonyloam]

Re: Frost plug in head of 470????

Right there, part# 10 http://www.mercruiserparts.com/Show...&bnbr=90&bdesc=CYLINDER+HEAD+AND+ROCKER+COVER
You have to get the remnants of the old one out, clean out the hole and drive the new one in.

 

[stonyloam]

Re: Frost plug in head of 470????

Hate to stop his trip short....but not being able to see it and diagnose it...hate to cause a problem since it is a fresh motor.

Any thoughts appreciated.

Should be OK, just noisy.

 

[sdoomaha]

Re: Frost plug in head of 470????

Dead on Terry...thanks for the help. He'll hit the local dealer in the AM and get a replacement. Said nothing left behind, so will just be tapping the new one in.

Thanks for saving 3 days of vacation for him....truly appreciated.