The "Ultimate" DIY - Complete Oil Pump Nut write up. (LONG)

[ChadsM3]

Greetings...

Many of you out here were like me a one time. "What is this oil pump nut issue. And...should I be concerned?"

Well, the short answer is YES.

Here's the deal. The oil pump to the E36 M3 is located in oil pan area and is bolted to block. The pump is chain driven off the crank. The sprocket that drives the pump is held on the pump shaft by a single 4mm thick reverse threaded nut. Under certain conditions, this nut WILL back off. There are many conditions out there that are suspect, but simply put the nut will eventually back off.

Now onto my car. I have a 1998 M3 coupe with 59K on the ticker. One would think "hey...no worries." Boy was I mistaken. Upon opening the oil pan, etc...the nut WAS in fact loose. Not only loose, but fell off in my hand when I touched it.

So in order to help those out there who have questions, I have decided to take the time and do a complete writeup.

Now...my disclaimer. I am doing this as one enthusiast to another. If you have problems changing oil or even tires, DO NOT PERFORM THIS PROJECT. I will not be held responsible for someone not referring to a qualified mechanic first or even a proper service manual. More: This is NOT a guarranteed fix. Short of spot welding the nut, this appears to be my preferred method to solve this issue. We'll see if it works.

Onto the chore at hand. Plan on 7-8 hours (taking your time)

Tools needed:
Screw drivers (flat and philips)
Misc metric sockets (deep and shallow)
Torque wrench (capable of light loads)
Torque wrench (capable of heavier settings)
wire for temporary hanging of components
Oil & filter
Power steering fluid (I use Mobil 1 ATF)
Engine hoist / brace
Eye protection
A Punch
Hammer
Bentley Manual or equivalent <--You need one, get it.

Parts:
High temp Loctite
Gasktet Sealer - Permatex High temp Black
Oil Dipstick O-ring
Oil Pan gasket
New Oil pump nut

Step 1: Disconnect the battery and securely place the vehicle on stands. I personally recommend the highest yet safest height you can go. The more room you have, the easier it will be to move around. Remove the front wheels / tires. (Note: I removed all my wheels due to time for a rotation.)



Step 2: Once the vehicle is safe, get under neath and remove the underpan and "porkchops". Next, get a good look at the components under the engine. Note the sway bar, crossmember, steering rack, and the power steering lines from the resevoir.

Step 3: Let's begin. Drain all the oil and replace the filter. (Now's a great time.) Note: Get as much oil out as you can. It's going to be messy.

Step 4: If you have an X-Brace, now is the time to remove it.

Step 5: Find the oil dipstick (Located on the right rear of the engine. Red loop for a handle. Unbolt it (on the intake manifold) and gently pull the dipstick tube out. Be gentle!! There is a breather hose attached to the assembly and it will not come out all the way.

Edit: Step 5.5: Find the droplinks that connect the front swaybar. Disconnect the bolts from the top that attach to the strut (these are easier to get to). Next remove the chassis supports and remove the bar.

Step 6: Disconnect the primary belt that drives the power steering pump and alternator. Side note: tuck the belt aside. It will be in your way later.

Step 7: Unless you have room to get to the Power steering fluid resevoir, remove your intake and filter assembly. And...then, with a clean syringe remove as much of the power steering fluid as you can. DO NOT REUSE IT!!

Step 8: Unbolt the Power steering pump and wire tie it to the radiator support beam or the engine brace (engine brace worked well for me.) Side note: you may have to remove the pulley for easy access. (see pic)



Step 9: Attached your engine brace / hoist to the engine lift point next to the oil filter. Now gently lift the engine approx 1/4" up. (see pic: hook is in center of pic)



Step 10: Working under the car, seperate the steering column shaft from the rack at the universal joint. BEFORE YOU DO THIS MARK THE SHAFTS' LOCATION!!!

Step 11: With a jack, support the crossmember frame under the car and remove the 2 - 18mm bolts on each side.

Step 12: Remove the nuts on the engine mounts and gently lower the crossmember about 1/2".

Step 13: Slowly disconnect the line from the Power Steering Resevoir to the Rack. NOTE: HAVE EYE PROTECTION WHEN YOU DO THIS. Fluid WILL dump on you. Drain of the access and plug the line from the rack. (see pic, hose in on the right)



Step 14: Continue lowering the crossmember as far as it can go. Be gentle, the ball joints will be extended at this point. (see pic)



Step 15: Remove the three bolts at the back of the oil pan. These join the oil pan to the transmission case. Note: These may be tight. Be careful.

Step 16: Remove the oil pan bolts. Note: there are two hidden ones at the back of the pan. Look for two holes right next to it.

Step 17: Once ALL bolts are removed, gently lower the pan, pulling it towards the rear of the car. If it doesn't want to move, use a rubber mallett to gently POP the gasket. Be gentle and note the location of the oil pickup and the oil pump sprocket near the front. (see pic)



There you go!! You got the whole assembly off.

Step: 18: Inspect the oil pump nut. Is it loose? Remove the nut. Note: it has left handed threads.

Step 19: Clean the threads and the sprocket, removing all oil residue. CLEAN THOROUGHLY!.

Step 20: Place a drop or two of High Temp Loctite inside the threads of the nut and tighten to 18ft-lbs.

Step 21: Take your punch and place the point right on the nut and shaft's threads. Note that the metal is quite soft and it won't take much of a whack to deform the threads. Side note: I did mine in 2 locations just for piece of mind. (See pic)



Step 22: Installation of the pan is the reverse. However, be sure to clean the gasket surface and use the Permatex gasket sealer on the corners of the oil pan. Next, when reinstalling the oil pan torque the bolts moving front to back.

That's all. My only advice is to take your time and look up the appropriate torque specs on all nuts and bolts. It's not a bad job, just time consuming.

I hope this helps. If you have any questions, feel free to PM or email me anytime.

Good luck.

Chad A.

[AntiHero]

Great ill have to check mine soon. Now I have a writeup to go by! Thanks man

[///Mink]

Great writeup, Chad. Now you've sufficiently frightened me into needing to do this (89K miles). I may MIG weld the nut to make sure it doesn't go anywhere.

[mmaigret]

Great write-up. A couple of short-cuts...

Step 7/13 You don't really need to disconnnect the line(s) from the power steering reservoir. I found it easier to just unbolt the reservoir from its mounting location; that way, no fluid mess and you don't need to worry about putting pressure on the power steering lines and fittings (the whole reservoir can be dropped down with the subframe once it's unbolted).

Step 8 If you leave the top, outboard bolt engaged, but loosened a bit, you can just swing the power steering pump out of the way when removing the oil pan. This will save you the trouble of "wiring" the pump.

Otherwise, great job and well done.

Mike

[ChadsM3]

Thanks Mike. You are correct on Step 8. I noticed this afterwards. However, on step 7/13. With my Dinan intake, it was an absolute pain to get in there and remove the resevoir. Also, the lines on my power steering assembly were very tight with not a lot of slack. I would have done just what you suggested, but also would have run the risk of bending a fitting or crimping a metal line. So I took the safe way out.

All in all, Mike makes some good alternative solutions. So based upon your own setup...determine the best method for you.

Thanks again Mike, good points. The more info, the better. Maybe this will end up helping somebody down the road.

best,
C.

[Balthazarr]

Shudder...

In step 9 you say to raise the engine 1/4", but in step 12 you say to lower the x-member AFTER removing engine mount nuts.
Seems a bit out of order wrt removal of the nuts. Can't raise the engine without removing/loosening nuts first, correct?

[phillyB///M3]

Sweet write up... got to check mine too.

[clumpymold]

Wow, that seems like a LOT of work. I might actually have someone do this for me (especially since I don't have the engine lift). Any idea what this will cost? If I've never tracked my car, is this absolutely "necessary"?

[Pinecone]

Source on the nice engine brace?

[Brent_Vino]

After seeing what is involved..... I'm glad I had my shop do this job for 300.00 a few months ago.


nice write up.... way over my head though.

[clumpymold]

After seeing what is involved..... I'm glad I had my shop do this job for 300.00 a few months ago.


nice write up.... way over my head though.

Yeah, I think I'd pay $300 to get this done for peace of mind.

I also think pictures at EACH step would have made this project a LOT easier and less daunting.

[EpDarks]

Looks scary if you ask me...

Nice writeup none the less.

[BrazeauRacing]

Source on the nice engine brace?

$60 at Harbor Freight (EDIT: now on sale for only $49)...
http://www.harborfreight.com/cpi/cta...emnumber=36092

It worked great when i did my oil pan and checked my oil pump nut...

[BrazeauRacing]

I also wanted to add that this is a great time to replace your motor mounts...

[clumpymold]

$60 at Harbor Freight (EDIT: now on sale for only $49)...
http://www.harborfreight.com/cpi/cta...emnumber=36092

It worked great when i did my oil pan and checked my oil pump nut...

Hmm, that's not too expensive. It's even on "sale" now for $50.

Is there ANY way to check this without going through all this?

[BrazeauRacing]

Is there ANY way to check this without going through all this?

Unfortunately, no. Mine was tight when i took my pan off, but i know that it is DEFINITELY not coming off in the future.

[DocWyte]

Is it just me, or does this seem to be more of an issue on the 3.2 motors than the 3.0 ones?

[ChadsM3]

Doc,

I have heard the same issues for all E36's. 3.0 and 3.2 alike.

And, guys...all the work to do this is very simple. I will say again, if you are not comfortable, let a pro get the dirty work done. As for prices, I have heard anywhere from $300 to $600 for the work. I strongly recommend a second estimate at a comparable shop. A good comparison is always handy.

Good luck all...

Chad

[ChadsM3]

Hey Admins...

Since I getting a lot of questions on this subject, could we park this one for a month or so?? Thanks.

Chad A.

[///Mink]

I'm right in the middle of this job this evening (inspired by Chad's writeup).

Just a point of clarification - When Mike mentions unbolting the PS reservoir from it's mounting point, I think he means to undo the one 10mm bolt holding the metal band around the reservoir, not the two 13mm bolts behind the reservoir. After removing the 10mm bolt, it's pretty easy to expand the band and drop the reservoir. I wasted time trying to access those 13mm bolts to no avail.

Onward to dropping the subframe...

[///Mink]

And the verdict is......

.....

...

....

Mine was tight. However, it could just as easily come loose on the way to work tomorrow. I'm going to go ahead and mig weld mine and have the oil pan baffled while I'm in there, so it's not wasted effort.

BTW, I also had to drop my (not stock) swaybar to get the pan off.

As a data point, My car has 89K on it and sees regular track use.

[Ian F]

Excellent write-up!

Has anyone considered safety-wiring the nut? Would it be possible?

I get a sneaking suspicion I'll be doing this project in the not too distant future.

[ChadsM3]

...BTW, I also had to drop my (not stock) swaybar to get the pan off.

As a data point, My car has 89K on it and sees regular track use.

Thanks!! I kept having this strange feeling I forgot something. Amazing that nobody else caught it.

It has been added.

If anyone else finds something, let me know. I will add it to the write-up.

best,
Chad

[Suneal]

Here's another DIY: http://m3.digital7.com/oilpumpnut.php (in this one, the nut is safety-wired)

[ChadsM3]

Shudder...

In step 9 you say to raise the engine 1/4", but in step 12 you say to lower the x-member AFTER removing engine mount nuts.
Seems a bit out of order wrt removal of the nuts. Can't raise the engine without removing/loosening nuts first, correct?

Balth - These steps were taken directly from the Bentley manual. The engine mounts will spread when you lift the engine. When you remove the nut after, they remain spread and are easier to get into position when reassembly takes place.

-Chad