crack in engine block?

[fixkick]

Thanks, yes it is a 16V head.....will keep you updated.

the 16v head has freeze plugs  (15mm?) on top VC valve cover off. seen  3 of them in top of head, on center line. ( I examine them at valve adjust ment time)
when and engine freezes, the first expensive damage not hoses that flex but the #1 place to fail is the head, up high , love to freeze and the freeze plugs up top blow out
seen with VC simply removed. caused by running pure  water not AF. for coolant. 
 
if oil in pan is clean , most things are good.   there are more freeze plugs one in front too. (head)


The tests that fail are, in order of cheap to more expensive tools and labor are.: (assumes full tune up done, sparks and fluids/filters)

1. eyeballs,  on dipstick or drain oil from pan and replace it, if old oil is full of AF it turns to chocolate moose. nasty milk chocolate.
   
2. VC pulled off and 3 below  seen freeze plugs. but above  fails too.
   
3. Vacuum gauge at idle not 20inches Hg. (19?) but bounces like mad (failed) a  $20 tool,   or vacuum acts backwards and the CAT MELTED.
   
4. SPARK TIPS BLACK. CAUSE UNKNOWN YET BUT IS BAD. TIPS green with AF ,is freeze damage or warped head.
   
5. compression not at 185psi,  x4,  bad valves or warped head gasket failed too.  ( one or more can fail and the numbers (psi) matter)
   
6. cam belt slipped and compression x4 is 100 pathetic.  timing wrong here (cam,) and for  sure spark as a result.
   
7. spark timing set all wrong by PO. or? someone. or is caused by #6 above.
   
8. there are for sure  other odd failures, like cracked valves, flat cam lobes, failed camshaft can fail with a lobe near worn down. (huge  lifter noise) solid lifters on this engine.
   
9. one good check is valve lash gone (tight),  or very loose. if lash is good, (gap) we get that good feeling with that. bad valves never hold lash good. valve recession called.