Oil or grey milky look inside of radiator cap?

2006 PONTIAC GRAND PRIX
180,000 MILES • 6 CYL • AUTOMATIC
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JUGGALO45
  • MEMBER
  • 88 POSTS
That's about it. The car listed above is a GT model with 3800 series 3 engine. Greyish oil like look in radiator and a little knocking coming from I think the water pump.
Jan 24, 2023 at 11:07 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,224 POSTS
The knocking is probably the balance shaft inside the engine. Here is an exploded view so you can see what I mean. Also, does this engine have an oil cooler and is the engine supercharged? Also check the engine oil to see if there is coolant? There might be a crack in the block that is allowing engine oil to leak into the coolant.
Jan 26, 2023 at 3:24 AM
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