car running really choppy, sounds like a miss

1999 CADILLAC STS
199,850 MILES • V8 • FWD • AUTOMATIC
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MUNCHP3
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  • 2 POSTS
I have just purchased this vehicle, supposibly the motor was replaced and only has approx
75,000 on it. I ran a compression test thinking blown head gasket but came back with decent compression all the way around. Also have noticed there seems to be a oil leak that I thought was coming from the head but maybe the valve cover. What else can I check that would cause this car to run really hit and miss and chug while idling. Also bad smell from the exhaust, excessive white smoke, as well as antifreeze in my oil. Also have replaced plugs and wires.
Mar 15, 2015 at 2:31 PM
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HMAC300
  • ✓ASE Certified Mechanic
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if you have antifreeze in oil and white smoke it's probably a head gasket. if your compression had any cylinder that was 20% difference then it's no good. scan for codes too
Mar 15, 2015 at 3:51 PM
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MUNCHP3
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Is there something special that i need to do to these heads to change the head gasket? Ive been told that there is something inpaticukar that needs to be done on these cadillacs.
Mar 15, 2015 at 4:12 PM
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HMAC300
  • ✓ASE Certified Mechanic
  • 48,601 POSTS
  • ASE Certified Mechanic
it's not the heads sometimes the head studs pull out of the block
Mar 15, 2015 at 4:37 PM
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