Question

Why would I be getting coolant into my oil on my truck?

Answer 1

Getting coolant into your oil can be caused by two different things which are the intake manifold gasket or the head gasket leaking.

If the intake manifold on your truck is not the plastic kind and is metal and your thermostat housing attaches to the intake manifold then it's likely that the intake manifold gaskets that are there to seal the coolant passages from the engine oil have failed and are leaking the coolant into the oil.

A bad intake gasket can not only cause coolant to leak into your engine oil but can also cause engine misfires or stalling as it's not sealing properly and allowing too much air into the intake.

If you have the plastic intake manifold which I've seen on some cars but not trucks yet then you could have a blown head gasket.

Most commonly though the coolant leaking into the oil is almost always just a faulty intake manifold gasket leaking.

Answer 2

I had the same problem on an old 1992 Chevy Silverado 1500 5.7 l engine truck that put coolant into the oil and it made the oil more watery than oily which was bad.

I also had water coming out the cylinders and yes it turned out to be the intake manifold gasket leaking on the intake manifold.

After replacing the intake manifold gasket and changing the oil and getting all the coolant out of the oil pan the truck ran like new and the coolant didn't get back into the oil.

So change your intake manifold gasket or have the intake manifold gasket replaced as it should fix the problem.