Hey guys, though I’ve been working on cars for years now I’m new to this group and new to owning a classic car. I just bought my E30 a few weeks ago and though everything looked good when I picked it up, I suspect I didn’t pick up on a potential blown head gasket. Let me give you guys a brief history of the car: The car has 95k miles on it and is in excellent condition overall. It is a 325i convertible and I have a few service records on it from the previous owner. She had told me about it losing coolant a few years back where she took it in and had the water pump replaced. She had told me car didn’t leak coolant since; I suspect this was a lie. I have been losing coolant since I purchased the car. About a quart of coolant is lost every few days. The car only drops in coolant level when being driven and overheating, it usually just goes to the first line above the middle line and bounces back to the middle after driving. No leaks under the car except sometimes small drops when moving which I suspect are coming from the overflow hose. Pressure test shows no external leaks. I did the oil change when I purchased the car and I drained 7 quarts of oil, yes SEVEN. It was not milky, but rather black like any old oil is. I did however notice milkiness under my oil fill cap. Wiped it off and a few weeks later checked under the oil cap again... milky. Dip stick also milky about 10-15 minutes after car has been shut off after a drive, but looks like normal after checking the dipstick after sitting overnight. I did notice however that the oil level on the dipstick is going up ( I suspect as I’m adding more coolant that’s where it’s going). Now before I start tearing this motor apart any pointers on how I should go about it as it’s my first big job. Can I confidently say it’s the head gasket? Should I be expecting a cracked head? In what ways can I further confirm that this is a head gasket job before I get started? Here are some pictures I tried to get of where the head meats the block: https://imgur.com/a/D0aQFwc
Looks like your head gasket does show some oil seeping probably from the head gasket fairly common problem. As for the coolant into the crankcase, this is most likely caused by a bad head gasket or cracked cylinder head or block. Normally when a head gasket leaks exhaust gas will from the cylinder will leak into the coolant passages. You can check this looking for bubbles in the coolant or using a dye that goes into a tube that you put over the coolant expansion tank opening and changes color if there is exhaust gases. That would indicate the head gasket is leaking. But since yours is going into the crankcase that test may not work. The milky ness on the dipstick is most likely moisture build up and can be normal to some extent. Best thing to do is replace the head gasket and check the head for cracking and probably have it planed.
