[T2] Power loss in 4th

[Jamie]

well.. I really don't think the spark plug is your issue... when they loose 
compression,, you know it!  because the go BANG! then puff air in and out..
otherwise the spark plug was still in place,, hot or cold.. it was still 
sparking,, and there would be no loss of compression,, but if there was loss 
of compression,, you would have heard it leaking past the plug like a big 
whistle.. or squirrel,, or chipmunk....... from my experience anyway....

if the helicoil came out neatly.. you can insert another in the same 
threads..  what I find is the ones that come out were not installed deep 
enough and the plug tightened on the coil before it hit the head... if it 
was a helicoil insert.. and it came out..... i dunno

so , pop in a new helicoil,, and do your compression checks again... heat up 
the engine till it looses power ,, and do a compression test again...
while you're checking the compression,, check the valve lash too...  use a 
VAC gauge on the manifold ,,
 and if you have hyd lifters... make sure they are rock hard and not squishy

good luck!
Jamie

----- Original Message ----- 
From: "Avocado Tom Tarka"

Jamie,

I think you were close with this, but I believe it was actually a bad 
helicoil someone put in the #3 spark plug hole: as soon as it got hot 
enough, it would lose compression and power.

Helicoil came out when I was trying to do another hot compression test.


On Oct 31, 2015, at 4:18 PM, Jamie <jrivers at globalserve.net> wrote:

>>> John Rogers  wrote:
>>>
>>> I am still convinced until proven otherwise that this is a case of
>>> pre-ignition. It has all the symptoms -- starts fine, runs OK until 
>>> warm,
>>> then loss of power.
>
>
> my wild ass guess is ... dropped valve seat...... the seat is in place 
> till the head warms up,, then starts to rattle around and cause all kinds 
> of issues.
> best way to find out.. use a VAC gauge on the manifold ... when you see 
> that needle flicker ,, sigh,, you will know ..
> you might  run some hose to the dash so you can watch it while driving , 
> if it doesn't act up as soon as you put the gauge on.
>
>