oil pump gasket and freeze plugs

8/3/2019 Oil Pump Gasket and Freeze Plugs

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Instead of removing the "Freeze Plugs" and tap threads for an "NPT Thread" Plug, I

decided to use an M7 bolts + washer for repair, and it works great (see

below).

To check for a Freeze Plug Leak, use a mirror and flashlight:

* Info on drive belt layout and belt tensioner (32-mm thin wrench for Fan Clutch Nut

and 5/16" Allen wrench for tensioner):

http://www.bimmerboard.com/forums/posts/199986

* Info on how to remove Air Filter Housing is part of my DIY for ICV, CCV etc.:

http://www.bimmerfest.com/forums/sho...d.php?t=379225

NOTE:

- Check realoem.com for your PN.

- Check your belt layout and make a diagram before taking it off.

- The PN for my 1998 528I Oil Filter Housing Gasket is

11421719855 ($5.00 at BMW dealer).
http://www.bimmerboard.com/forums/posts/199986http://www.bimmerfest.com/forums/showthread.php?t=379225http://www.bimmerboard.com/forums/posts/199986http://www.bimmerfest.com/forums/showthread.php?t=379225


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- Observe Torque Values (look it up) for different bolts.

M8 bolts = 22 Nm (Oil Filter Housing)

M10 bolts = 33 Nm

---------------------------------------

PART I: OIL FILTER HOUSING, ALTERNATOR REMOVAL

1. Disconnect Battery Positive Terminal in the trunk (10-mm wrench, be careful not

to short with the ground bar!)

2. Remove Fan Clutch: 32-mm wrench. Note it is REVERSE thread!

During re-installation if you have difficult threading the Fan Clutch Nut back on the

Water Pump bolt, you can use my "Poultry Cord" trick:

http://www.bimmerfest.com/forums/sho....php?p=2758628

Use 5/16" Allen wrench for tensioner to remove belt.

3. Disconnect the DSC System Connector.

4. Remove the Air Filter Housing/Air Mass Meter as a Unit. Remove the 10-mm bolt

and clamps and wiggle the whole thing out watching not to damage the Intake

Rubber Elbow.

5. Remove the 13-mm Bolts the PS Reservoir and set it aside:
http://www.bimmerfest.com/forums/showthread.php?p=2758628http://www.bimmerfest.com/forums/showthread.php?p=2758628


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6. Alternator is mounted by two (2) 16-mm bolts. The UPPER Bolt holds the Pulley.

The positive cable connection is a 13-mm Nut.

- D/C connector

- D/C Cooling Air Intake

- Then Alternator comes out (It swivels on the LOWER bolt).

- During re-installation, use a smaller rod or screwdriver to help guide the Alternator

back on the slot.


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7. To remove the Oil Filter Housing:

- Disconnect VANOS Banjo-style Oil Line attachment to the VANOS using 19-mm

wrench.

Do NOT lose the 2 aluminum washers, I re-use these washers. Torque for this 19-

mm Banjo Bolts: 32 Nm.

- Optional: Remove Tensioner (Yellow Arrows) using 13-mm sockets. You don't have

to do this step as it can be left attached to the O.F. Housing.

- The O.F. Housing is held by a total of 8 bolts.

- The six (6) 13-mm bolts have different lengths: mark them #1-6 to avoidconfusion. In the event that you forgot to mark them, no worry, I laid them out in

order as shown.

- Remove two (2) 13-mm bolts (# 7-8) on top of the PS Pump.


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8. Now the O.F. Housing comes out easily. Remove old gasket and clean the mating

surfaces to make sure it is spotless for re-installation.

9. If you decide to de-grease this area, go slowly!!! Stuff a rag inside the Engine


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Housing to prevent dirt or water from coming in. Avoid garden hose or pressure

washer for obvious reasons!!!

- Wipe it clean with a rag and Q-tips so no oil is left behind.

10. Have a look at the O.F. Housing:

- Note the Oil Pressure Sensor on the back side.- Note the Engine Oil Anti-Drain Back Valve.

- When installing new gasket, I use a thin smear of grease to seal any imperfection

(this is just my way, you don't have to do it).

- Check both the mating surfaces to be sure it is spotless before re-installation:


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- The Gasket barely sticks out (maybe 0.2 mm), so avoid using additional gasket

maker here because it can potentially affect the Factory Gasket sealing:

Re-installation:

- Straightforward.

- Note all connectors and re-install them.

- Watch torque values.

- Wipe all oil leak in engine compartment and along oil pan gasket area so you can

monitor these areas later.

- Re-connect Battery Positive Terminal.

- Start engine and check for any oil leaks at Housing or Banjo connection.

Congrats, you just spent $5.00 and saved some 4h of labor charge at dealer or indy!

Now let's move on to fixing the Oil Filter Housing Leak itself.


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---------------------------------------

PART II: OIL FILTER HOUSING "FREEZE PLUGS" LEAK REPAIR

- After the following repair of "Freeze Plug" Leak, my car is bone dry, not a single

drop of oil leak!

Parts List (All of these can be obtained at Ace Hardware Store) for about $12.00:

- Stainless Steel M7 x 10 mm bolts; qty = 2.

- Optional: M6 x 10 mm bolts; qty = 2 for "dry fit".

- Stainless Steel Washers O.D. = 1-1/4"; I.D. = 5/16" (5/16" = 8 mm to accept the 7

mm bolt).

- Red LocTite, small tube

- Permatex Black RTV Gasket Maker

- Roofing Black Asphalt Caulk


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- The "Freeze Plugs" are actually not "Freeze Plugs" but basically Welch Plugs that

are stake-punched in from factory to close off holes from casting. It should have

been plugged with bolts and washer (later models use bolts and washers). But this

design of "Freeze Plugs" is known to cause oil leak in different BMW models.

- A new O.F. Housing is $330!!!

- The leak from my "Freeze Plugs" is about 4-5 drops on the driveway every night.

But there is more leak than that (oil blown off on the road and collecting under the

oil sump).

1. The hole in the "Freeze Plugs" is made from Aluminum and has a diameter of 6

mm and the M7 bolt fits perfectly.

- Do a search on tap and die of bolts and nuts, but as a rule, the hole to be threaded

is always a bit smallerthan the new bolt. This is because the M7 bolt has a diameter

of 7 mm measured at the tip of the pitches but the measurement at the valley of


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the pitches is about 6 mm.

- To tap new threads, you can use a tap and die set but if you don't have a tap/die

set, no problems. Use the M7 bolt to tap it with 1/4" ratchet. Keep steady pressure

and maintain perpendicular path. The bolt is Stainless Steel and the Plug is

Aluminum, so the bolts makes new threads with no problem (this is what I did).

- Tap a few turns at a time while removing the metal fragments. The hole is about 5mm deep.

- Clean the hole from any debris:

2. Now use the smaller M6 x 10 mm bolt to make sure it fits nicely. The idea is:

the washer should be 1mm from the housing. This is because this space will beoccupied by Permatex RTV Gasket Maker, which will cure into a rubber-like material:


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3. Now fit the washer and the M7 x 10 mm bolt as a "dry run". When the bolt is

completely in, you should see a 1mm gap between the washer and the housing. Do

NOT over-torque this M7 bolt, very easy to strip it!

- Now, remove the bolt and washer and proceed with the sealing job.

4. Apply Roofing Black Asphalt Caulk at the edges. This is where the oil leak

happens. The Black Asphalt Caulk will seal it nicely and has a wide range of temp

tolerance.


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5. Now apply Permatex RTV Gasket Maker as shown, leaving the hole alone. Use Q-

tips to clean the hole:


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6. Place washer then rotate it a bit to spread the RTV sealant. The Permatex

procedure calls for letting the sealant cure for about 2h before tightening the bolt.

However I install the bolt right away, read on............

7. The M7 x 10 mm bolt: apply a drop of LocTite on the thread and a very small drop

of RTV sealant near the bolt's head. Again, use 1/4" ratchet and do NOT over-torquethis M7 bolt, very easy to strip it!

8. When the bolt is fully seated, you should be able to rotate the washer because

there is 1 mm gap filled with RTV sealant (but after 24h of cure, the RTV sealant will

be rubberized and you should notbe able to rotate the washer).

- Clean excess RTV Sealant. This is what it looks like prior to re-install:

9. The key thing: you can install everything back in the car but don't start

the engine until 24h later to allow the RTV Sealant 24h to completely cure.

oil pump gasket and freeze plugs

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