Oil Leak; I am frustrated, please help.

[Al Gray]

I have an oil leak that is dripping a drop at a time from the driver's side rear corner of the oil pan. It looks like it is dripping down the oil pan. Do I have an oil pan leak or is there something else that I should check before I do the (shudder) oil pan gasket job? I have already replaced the valve cover gasket and grommets today hoping that would take care of it but it did not. Any comments would be appreciated.

[andyman32]

Locate the leak - if it's the oil pan gasket, then that's that. Easy as pie. I'm about to do that on mine. Other than that, i don't know what else to recommend without knowing more about the origination of the leak.

[Jr ///M5]

The oil pan bolts on the 525 and 535 are notorious for becoming loose due to the cork construction of the gasket shrinking. Before you tear into a gasket repair, check the tightness of the bolts with a 1/4" drive ratchet and 10mm socket with extention. Don't overtighten them, that could cause the gasket to pop out of place. Just make sure they are tight before you proceed with a gasket job. I had the same problem with my old 535 and went around the whole pan getting at least a turn and a half out of them. That stopped the leak....

Hope this helps,
Jr

[andyman32]

Bah, why such hesitation on the gasket job? Is it more complicated than I'm thinking it is? I got a new lower oil pan gasket for $14.20 from BMA. Whenever you need to change out your oil anyhow, drain the oil, take out the 20 or so bolts, pry off the pan, then slap a new gasket up there. If you're dexterous with your 10mm socket driver, it should only add about 30 minutes to the next oil change.

I must not be properly anticipating something...

[Al Gray]

Bah, why such hesitation on the gasket job? Is it more complicated than I'm thinking it is? I got a new lower oil pan gasket for $14.20 from BMA. Whenever you need to change out your oil anyhow, drain the oil, take out the 20 or so bolts, pry off the pan, then slap a new gasket up there. If you're dexterous with your 10mm socket driver, it should only add about 30 minutes to the next oil change.

I must not be properly anticipating something...

Andyman,

Here is the proper anticipation. I wish it was as easy as you described.

On page 119-5 the Bently manual lists the following procedures:
1. Drain engine oil
2 Disconnect oil level sensor
3. Remove the radiator cooling and the fan shroud (need special 32 MM wrench for left hand threads)
4. Release the drive belt tension and remove the engine drive belt
5. Remove the power steering pump and its bracket from the engine block.
6. Remove the oil dipstick guide tube mounting bolt and remove the tube.
7. On cars with automatic trans, remove the brackets that hold the ATF cooler line the the oil pand and cylinder block.
8. Remove the oil pand mounting holder and lower the oil pan to the subframe crossmember.
9. Unbolt the oil pump pickup tube from the oil pump and then remove the oil pan from the rear.

As you can see it is not as easy as taking out the oil pan bolts and dropping the pan.

[andyman32]

OHHH, okay, I see what you're talking about. Upper pan gasket. See, I was just talking about the lower pan gasket. Youch, that doesn't look like much fun AT ALL. Good luck with that one man.

Andyman,

Here is the proper anticipation. I wish it was as easy as you described.

On page 119-5 the Bently manual lists the following procedures:
1. Drain engine oil
2 Disconnect oil level sensor
3. Remove the radiator cooling and the fan shroud (need special 32 MM wrench for left hand threads)
4. Release the drive belt tension and remove the engine drive belt
5. Remove the power steering pump and its bracket from the engine block.
6. Remove the oil dipstick guide tube mounting bolt and remove the tube.
7. On cars with automatic trans, remove the brackets that hold the ATF cooler line the the oil pand and cylinder block.
8. Remove the oil pand mounting holder and lower the oil pan to the subframe crossmember.
9. Unbolt the oil pump pickup tube from the oil pump and then remove the oil pan from the rear.

As you can see it is not as easy as taking out the oil pan bolts and dropping the pan.

[Dick Schneiders]

Bah, why such hesitation on the gasket job? Is it more complicated than I'm thinking it is? I got a new lower oil pan gasket for $14.20 from BMA. Whenever you need to change out your oil anyhow, drain the oil, take out the 20 or so bolts, pry off the pan, then slap a new gasket up there. If you're dexterous with your 10mm socket driver, it should only add about 30 minutes to the next oil change.

I must not be properly anticipating something...

[Stacy (Sydney)]

I had exactly the same leak - turns out there is a common leaking point on the beemer 3.5 litre six : I hope this is clear enough - there is a triangular thing on the front of motor ( north of sump, about 1/2 way up block), held on by ( i think ) 3 bolts. One of these gets loose , hence leak. If there is what looks like built up grime in this area ( look in from rhs of engine bay ), spray degreaser - and you may see what I mean. check the bolt closest to you when looking in to engine bay. I don't have photo's to post, and buggered if I know what the part is called that you have to tighten.

[Al Gray]

I had exactly the same leak - turns out there is a common leaking point on the beemer 3.5 litre six : I hope this is clear enough - there is a triangular thing on the front of motor ( north of sump, about 1/2 way up block), held on by ( i think ) 3 bolts. One of these gets loose , hence leak. If there is what looks like built up grime in this area ( look in from rhs of engine bay ), spray degreaser - and you may see what I mean. check the bolt closest to you when looking in to engine bay. I don't have photo's to post, and buggered if I know what the part is called that you have to tighten.

Stacy,

An update for this morning; I tightened all the pan bolts about 1/4 turn. The leak slowed down considerably. However, I still have an occasional drip from a small weep hole in the oil pick-up tube that is attached to the pan with three bolts. Also there is a very slight drip that seems to be coming from where the pick-up tube runs upward by the side of the pan. Depending on how anal I feel about this, I may replace the pan gasket and any other gaskets related to this matter. After I tightened the bolts on the pan I started the car and observed the area for several minutes. No leak! I went inside the house for a couple minutes and came out to check the area again and noticed the slight drip. Any comments or questions would be appreciated.

Al Gray

[Stacy (Sydney)]

Find the exact location of the leak before pulling things apart. If its an extremely slow leak, live with it. I'm a real novice on the m30 - I overlooked you had an m50. I'd also be careful not to overtighten any bolts. Good luck with it.