Oil in Coolant Identifying the Culprit and Restoring Engine Health

The coolant in a 5.3L Vortec does not communicate in any way with the intake manifold so a blown intake manifold gasket can not get oil into the coolant. Wouldn't oil in the coolant circuit tend to lay low (as in more dense) instead of showing 'up' in the overflow tank ? Either way, this would ... This is quite a common problem with the 272/273 motors. Replacing the seal alone will not fix the entire problem you have at this point. You ... In operation, oil is at higher pressure than the coolant, so if the leak is small you can get a slow migration of oil from crankcase to ... If you have oil in your reservoir you have a blown head gasket my friend. You can see it better in the reservoir then you can in the radiator. Typically it's an oil cooler failure. If the cooler wasn't properly torqued last time, it could have lead to the premature failure this go ... There is potential that your oil and coolant are mixing due to a broken head gasket or a cracked cylinder head. Open up the radiator cap and ... The most common sign of oil in cooling system is the presence of a slimy milky-brown layer in the coolant. Replace oil cooler. Fill cooling system w/ fresh water. Add a small(!) amount of detergent to coolant tank, run vehicle for a short bit. Drain. If you have oil in the coolant reservoir, then it means you have leaking head gaskets and oil is moving into the coolant and/or coolant is moving into the oil.