Compression issues..

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. The key to what you stated is - compression is backing up into the cooling system. The only way this happens with this vehicle and engine is when you have a breach of the cylinder head allowing exhaust back pressure into the cooling system, which also allows coolant into the combustion chamber and ultimately into the crankcase, diluting the engine oil. This is an indication of a cracked cylinder head or a leaking cylinder head gasket. If you can confirm back pressure into the coolant reservoir from the engine - this is the most likely cause. I would recommend a professional technician near you has a look and checks it out for a definitive evaluation. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.