M50 has separate coolant & oil leak?

[Dick Schneiders]

I have had a minor oil leak in my 1991 525i for several months now. It was dripping off of the rear of the oil pan, and was not the oil pan gasket or the oil level sensor. It seemed to be coming from somewhere higher up on the engine. I replaced the valve cover gasket a few weeks ago. The old one was in terrible condition - it fell apart in several places when it came out. I had hoped that was going the be the source of the oil leak, but it still continued. The oil spot on the driveway was very small - only an inch or so in diameter.

Over the same time frame I had a very slight loss of coolant with no leak or residue trace that I could see anywhere. I had to top off the coolant with a cup or so twice in the past several months.

However, in the past few days the spot on the driveway has gotten larger. I just now put the car up on ramps and watched as it ran for 30 minutes. The motor oil leak seems to be worse than before, as there were quite a few drops of oil that ran off of the back of the oil pan. Also, I saw a "separate", slower series of drops form and fall to the driveway that was obviously coolant. It, too, was coming off of the rear of the oil pan but in a slightly different place. Both leaks are mixing on the driveway, though, and that might be why I never thought I saw any evidence of a coolant leak. I have never had to top off the engine oil as the car does not use any oil to speak of and the leak has been quite small.

Any ideas? Could a headgasket problem produce two distinct leaks of these two different fluids? There has been no evidence of excess moisture being blown out of the exhaust and the car has been running fine. There was no evidence of any oil leaking into the spark plugs when the valve cover gasket was replaced. I can see no visible mixing of coolant and oil in the coolant reservoir or on the dipstick.

Thanks,

Dick Schneiders

[632 Regal]

I would venture to guess that you could have a head gasket leak, both fluids pass through it. At first I would have guessed the rear main seal but those arent real common on BMW as far as I read and since you are seeing both leaking...H-gasket. Can you take a better look or powerwash it back there somehow just to make sure whats going on?

[tim]

Do you have an automatic?

[Bill R.]

here, either where it bolts to the block or where the hose is clamped


And the oil leak could be from here on the back of the head.. Were the half moon pieces of the valve cover gasket seated correctly , i'd check there and see if its leaking for starters...

I have had a minor oil leak in my 1991 525i for several months now. It was dripping off of the rear of the oil pan, and was not the oil pan gasket or the oil level sensor. It seemed to be coming from somewhere higher up on the engine. I replaced the valve cover gasket a few weeks ago. The old one was in terrible condition - it fell apart in several places when it came out. I had hoped that was going the be the source of the oil leak, but it still continued. The oil spot on the driveway was very small - only an inch or so in diameter.

Over the same time frame I had a very slight loss of coolant with no leak or residue trace that I could see anywhere. I had to top off the coolant with a cup or so twice in the past several months.

However, in the past few days the spot on the driveway has gotten larger. I just now put the car up on ramps and watched as it ran for 30 minutes. The motor oil leak seems to be worse than before, as there were quite a few drops of oil that ran off of the back of the oil pan. Also, I saw a "separate", slower series of drops form and fall to the driveway that was obviously coolant. It, too, was coming off of the rear of the oil pan but in a slightly different place. Both leaks are mixing on the driveway, though, and that might be why I never thought I saw any evidence of a coolant leak. I have never had to top off the engine oil as the car does not use any oil to speak of and the leak has been quite small.

Any ideas? Could a headgasket problem produce two distinct leaks of these two different fluids? There has been no evidence of excess moisture being blown out of the exhaust and the car has been running fine. There was no evidence of any oil leaking into the spark plugs when the valve cover gasket was replaced. I can see no visible mixing of coolant and oil in the coolant reservoir or on the dipstick.

Thanks,

Dick Schneiders

[Jr ///M5]

Get one of those mirrors that telescope out (or the wifes makeup mirror...=) and a good flashlight so you can see between the engine and the firewall without crawling up on top of the motor...=) Good luck with it Dick!

Great idea Bill, showing the leak locations with the ETK. Now get busy and find out what's going to happen to us when we pour some Mobil 1 down the gullet of the E46 and the E39..=) Lori's is already due for another oil change...=(

Hope you guys had a Merry Christmas,

Jr

[Dick Schneiders]

Do you have an automatic?

[Dick Schneiders]

I appreciate the pictures.

[Bill R.]

I have the newer Tis on, yeah the tis that i don't like... anyway the newer one has more stuff on our m52tu motors... and here is the oil bulletin i found
Looks like mobil one 0w40 is just peachy.. Heres the pdf file on it.

Get one of those mirrors that telescope out (or the wifes makeup mirror...=) and a good flashlight so you can see between the engine and the firewall without crawling up on top of the motor...=) Good luck with it Dick!

Great idea Bill, showing the leak locations with the ETK. Now get busy and find out what's going to happen to us when we pour some Mobil 1 down the gullet of the E46 and the E39..=) Lori's is already due for another oil change...=(

Hope you guys had a Merry Christmas,

Jr