M30 Engine Rebuild Tips & FAQ

E28 technical advice asked and given! Troubleshooting, modifications and more.
tig
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M30 Engine Rebuild Tips & FAQ

Post by tig »

Here's a good item for the FAQ. Would have saved me a lot of time:

Q: What's the best order of assembly of an M30 motor?

Something like below. If you don't follow this order you will likely end up re-doing work.
  1. Oil pump and chain.
  2. Lower timing chain sprocket, guides, and timing chain.
  3. Lower timing chain cover. Don't forget to install the brackets for the timing sensor and shackle.
  4. Grub screw, AC compressor mount, PS/Alternator mount
  5. Rear main seal.
  6. Oil pan
  7. Install harmonic balancer temporarily so you can see crank TDC. NOTE: in my pic above I am NOT at TDC. The crank dowel pointing up DOES NOT indicate TDC.
  8. Set head to camshaft TDC before installing. TDC means the small dowel pin on camshaft is down and the two face bolts are aligned vertically.
  9. Head.
  10. Upper timing chain cover
  11. The rest is straight forward
EDIT: 7/8/2014 - I noticed the Haynes Manual has this order, FWIW
  1. Piston rings
  2. Crankshaft and main bearings
  3. Piston/connecting rod assemblies
  4. Oil pump
  5. Sump
  6. Cylinder head assembly
  7. Timing belt or chain and tensioner assemblies
  8. Water pump
  9. Timing belt or chain covers
  10. Intake and exhaust manifolds
  11. Valve cover
  12. Engine rear plate
  13. Flywheel/driveplate
Last edited by tig on Jul 08, 2014 5:14 PM, edited 2 times in total.
tig
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Post by tig »

Here's a set of questions I asked in building my M30B35 that other's might ask, with answers:

Q: I've never mounted an engine on an engine stand before. What bolt holes are best to use for an M30?

I numbered them in the picture below.
Image

A: Bolt holes 12, 4, 5 & 7. The AL piece just allows easy inspection of the flywheel. It won't hold any serious load.

Q: Should I take the flywheel off first?
A: Yes!

Q: How'd you get the Jesus nut (crank) off?
A: With a good air compressor and impact wrench, I just pounded away for about 2 minutes with a 36mm impact socket. Others have heated it up and used a breaker bar.

Q: What's the best way to clean caked on grime and cosmolilne off aluminum and plastic parts?
A: Soda blasting! Careful on the plastic to use a mild grain soda because it WILL make the plastic slightly more matte.

Image

Before:
Image

After:
Image

Image

A few minutes later:
Image

DO NOT USE A SAND OR MEDIA BLASTER FOR INTERNAL ENGINE PARTS. Those kinds of media will never come out and they will do what they were designed to do (abrade) when the engine runs.

Q: Are any of the fasteners on the engine (crank, camshaft, etc...) reverse threaded?
A: No

Q: Where can I get my fastners "zinc" plated?
A: www.arrowplating.com in Ft. Worth did a great job for me. I spent bout $60 including shipping for two sets of fasteners (I had two donor motors).

Don't include any stainless steel (hose clamps) or aluminum parts!

Image

Image

Note that many of your M6 wave washers will die a horrible death in the plating process (they are thin and the plating process weakens them, apparently), so buy extras.

Q: How do you keep what fastners go where straight
A: I used the following combination of techniques:

First, I took tons of pictures of the donor motors from all angles before and during dis-assembly. I also created a thread here for others to post their own pictures for additional reference: http://www.mye28.com/viewtopic.php?t=117074&highlight=

I put everything in zip locks when I tore down the donor motor and labeled the zip locks. Later I took pictures of the fasteners laid out on the zip lock so i could have a reference, since I couldn't keep them this way for plating.
Image

During re-assembly I laid all my fasteners out by size:
Image

As I needed a fastener I first checked RealOEM for the dimensions. Then I went to my set of fasteners with my ruler and picked the right fastener. I checked my photos if there was any ambiguity.

Q: I'm missing a part. I can't find it anywhere. Where might it be?
A: Have you checked the depths of your parts washer?

Q: Can I re-use head bolts?
A: No, but your new bolts will not come with washers so save your old ones!


Q: When I re-wrap the wiring harness, what kind of tape should I use?
A: F4 Tape. Buy it here.

Image

Q: If I need to put splices in my wiring harness what's the best splice technique
A: If you want reliability use high quality non-insulated butt/barrel crimp connectors with a quality crimp tool. Unless your technique is perfect, soldier is too prone to failure.

Image

Image

Image

Delcity.com calls them Barrel Butt Connectors. That's where I get them.
http://www.delcity.net/store/Non!insula ... s/p_801870
http://www.delcity.net/store/Insulated- ... ol/p_10426

Q: The oil pan gasket has turned to diamond. How can I remove it.
A: Soak it in diesel for a day or two. it will then come off with a gasket scraper.

Image

Q: Do I need to do any prep to the surface before putting the head gasket on (like make sure it's clean of oil or anything)?
A: You want the mating surfaces to be smooth and clean. Definitely no oil. Make sure the bolt holes are clean as well.

Q: How much is it going to cost me?
A: Way more than you expect.
mooseheadm5
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Post by mooseheadm5 »

These do not apply solely to an M30B35 swap, they work for all M30 builds, so I am splitting them off. Perhaps if everyone thinks they are helpful and complete enough, we can place them into the Tech FAQ section.
ahab
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Post by ahab »

I have reused M30 head bolts plenty of times with issue. Maybe I've just been lucky. Really make sure the holes are clean. A small amount of oil should be applied to the washers prior to torquing.
slammin_e28
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Post by slammin_e28 »

ahab wrote:I have reused M30 head bolts plenty of times with issue. Maybe I've just been lucky. Really make sure the holes are clean. A small amount of oil should be applied to the washers prior to torquing.
...without?

I've reused them before. I've replaced them before. Depends on how much I wanna splurge.

No problems either way.
ldsbeaker
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Post by ldsbeaker »

GREAT tips.

I would add:

Where do I use sealants and what type to prevent leaks on my brand new soda blasted/cleaned/zinc plated enginz?

Also,
How do I clean my rusty ass block, and then what paint can I use?
ahab
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Post by ahab »

slammin_e28 wrote:...without?
Si Si Si. Without.
Mike W.
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Post by Mike W. »

ldsbeaker wrote:GREAT tips.

I would add:

Where do I use sealants and what type to prevent leaks on my brand new soda blasted/cleaned/zinc plated enginz?

Also,
How do I clean my rusty ass block, and then what paint can I use?
I've never replaced head bolts and put hundreds of thousands on engines I've rebuilt. Without problems. Turbos might be another thing. Might.

Sealant? Pretty much just on anything you don't want to leak. Permatex #3. Timing covers especially, but also pan, rear main seal housing, Teflon tape on the plug for the timing chain tensioner, just everywhere is close.

And a FWIW if someone thinks it's overkill, my (ex) E28 had 175K on it from my rebuild when I sold it and while not spotless, didn't leak a drip. Not even from the timing covers. :up: OH, except the head gasket, it goes on dry.
JSmoove
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Post by JSmoove »

ldsbeaker wrote:GREAT tips.

I would add:

Where do I use sealants and what type to prevent leaks on my brand new soda blasted/cleaned/zinc plated enginz?

Also,
How do I clean my rusty ass block, and then what paint can I use?
Good question. I'd like to know this as well.
turbodan
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Post by turbodan »

I'm on the other side of the fence on sealant. I have had excellent results using nothing but a gasket. Water pumps, oil pans, timing cases, etc. With clean, undamaged sealing surfaces an ordinary gasket is perfectly sufficient. Sealant can be good for filling imperfections but should not be used in place of proper surface prep.
Cooperman
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Post by Cooperman »

The best sealant is Hylomar. It will not harden and potentially clog fluid passages if it breaks off.
vinceg101
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Post by vinceg101 »

I'll ask a few questions here (at Charlie's suggestion):

1. Timing Chain Guides: Can these be replaced without removing the actual Timing Chain itself?

2. Timing Chain Removal: Related to #1 if the answer is no: how hard is it to remove the Timing Chain itself?

3. Jesus Nut Removal: I know you managed to remove this with pneumatics while the block was out of the car, but is the preferred method for loosening the JN while the block is still in the car?

4. Media Removal: I inadvertently hit the interiors of some valve covers with aluminum oxide media. (Now I read cek's advice about avoiding this). What does anyone suggest about removing the oxide media? Hot dip power wash? Gasoline? Pressure washer?

5. Powder Coating: Should one powder coat the Oil Pan and Differential Cover or is this not recommended due to heat dissipation issues?

BTW, kudos to Charlie for creating this thread; it should be Sticky'd.
Last edited by vinceg101 on Jul 09, 2014 11:50 AM, edited 1 time in total.
tig
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Post by tig »

vinceg101 wrote:I'll ask a few questions here (at Charlie's suggestion):
1. Timing Chain Guides: Can these be replaced without removing the actual Timing Chain itself?
No. Or at least I can't imagine how you could.
2. Timing Chain Removal: Related to #1 if the answer is no: how hard is it to remove the Timing Chain itself?
Easy, but you have to remove both the front covers and the camshaft sprocket. I suspect you'll want to go ahead and do the head gasket if you go this far.
3. Jesus Nut Removal: I know you managed to remove this with pneumatics while the block we out of the car, but is the preferred method for loosening the JN while the block is still in the car?
That's what I understand. The reason being is the tranny is your counter force. It'll still be a bitch.
4. Media Removal: I inadvertently hit the interiors of some valve covers with aluminum oxide media. (Now I read cek's advice about avoiding this). What does anyone suggest about removing the oxide media? Hot dip power wash? Gasoline? Pressure washer?

5. Powder Coating: Should one powder coat the Oil Pan and Differential Cover or is this not recommended due to heat dissipation issues?
I want opinions on this as well.
BTW, kudos to Charlie for creating this thread; it should be Sticky'd.
Last edited by tig on Apr 18, 2014 5:30 PM, edited 1 time in total.
gaberdee
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Post by gaberdee »

The crank nut can be removed with the motor still in the car. I purchased an m30 hub holder from bavauto (about $80, if I recall) and a 4:1 torque multiplier. I removed the radiator and loosened the condenser mounting bolts to get as much clearance for the tools as possible.
slammin_e28
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Post by slammin_e28 »

The crank nut can be removed while engine is in the car by placing a breaker bar on it and placing the breaker bar on the frame rail or floor. Then, after disabling the engine from starting, hit the key real quick. She'll spin off by hand after that.

I made a holder tool with some old steel rod and a spare balancer. Indexed it so it would hold the crank steady at TDC while I torque down the Jesus nut with a bigass cheater bar and body weight.

Done.
Mike in Seattle
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Post by Mike in Seattle »

vinceg101 wrote:5. Powder Coating: Should one powder coat the Oil Pan and Differential Cover or is this not recommended due to heat dissipation issues?
I have been running a powdercoated oil pan and rear diff cover for close to 10 years with no problems. I would say go for it if that is what you desire!
vinceg101
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Post by vinceg101 »

slammin_e28 wrote:The crank nut can be removed while engine is in the car by placing a breaker bar on it and placing the breaker bar on the frame rail or floor. Then, after disabling the engine from starting, hit the key real quick. She'll spin off by hand after that.
I heard about this method, used with all the obvious precautions.
Mike in Seattle wrote:
vinceg101 wrote: 5. Powder Coating: Should one powder coat the Oil Pan and Differential Cover or is this not recommended due to heat dissipation issues?
I have been running a powdercoated oil pan and rear diff cover for close to 10 years with no problems. I would say go for it if that is what you desire!
Thanks! That's what I wanted to hear.
slimdevil27
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Post by slimdevil27 »

Q: How'd you get the Jesus nut (crank) off?
A: With a good air compressor and impact wrench, I just pounded away for about 2 minutes with a 36mm impact socket. Others have heated it up and used a breaker bar.
Remove the oil pan. Wedge a hard rubber mallet between a crank rod throw and the inside of the engine block, effectively locking the crankshaft. Use the same technique during reassembly.
Q: Can I re-use head bolts?
A: No, but your new bolts will not come with washers so save your old ones!
Damn head bolts. For the last fricken time, our head bolts are not torque to yield and do not need replacing. The confusion is that the torque sequence includes a torque to angle step. Torque to yield bolts have large diameter threads tapering to a very narrow shank and then taper back up to a large bolt head. Torque to yield bolts must be replaced after every use. In every single case that I've run across where a torque to yield bolt is used, the torque sequence includes at least one torque to angle step in the sequence, such as torque to 50 ftlbs then an additional 90 degrees. The final torque on ours is somewhere around 60 ftlbs. and while the sequence includes a torque to angle step, it doesn't mean they are torque to yield bolts. The yield strength of an m12, grade 10.9 is 92 ft lbs lubed and 123 ftlbs dry. As you can see, at 60 ftlbs you are about 25% below the yield strength of the bolt. The difference in the lubed and dry spec illustrate the need not only to lube the bolts for proper torque but also the importance of cleaning the threads for the correct torque to be achieved. Installing dirty lubed bolts has the equivalent effect of installing them dry as the increased friction of dirty threads reduces the final torque reading. In other words if you install the bolts dry and torque them to 60 ftlbs, the actual torque is about 30% less or approximately 40 ftlbs. Since some threads are cleaner and some are dirtier the result is uneven clamping force and a propensity for warped heads and subsequent repeated head gasket failure. Replacing these head bolts is an idiotic waste of money, especially if it makes you feel good.
Where do I use sealants and what type to prevent leaks on my brand new soda blasted/cleaned/zinc plated enginz?
The two sealants that you will need are Permatex aviation gasket sealant and RTV silicone. Anywhere you have two mating surfaces that are free of major imperfections use the aviation gasket sealant. For example front timing cover to block, water pump to housing, etc. Anywhere there is a complex joint, such as the head/block/front timing cover joint, or anywhere there is a void to be filled, use the silicone. Additionally anywhere you have a gasket that seals a joint of two separate components, like the oil pan to block/timing cover, a small dab of silicone should be used compensate possible height differences (fill the void).

This from turbodan:
I'm on the other side of the fence on sealant. I have had excellent results using nothing but a gasket. Water pumps, oil pans, timing cases, etc. With clean, undamaged sealing surfaces an ordinary gasket is perfectly sufficient. Sealant can be good for filling imperfections but should not be used in place of proper surface prep.
Absolutely agree. Especially on surface prep....clean, clean, clean AND DEGREASE.

How do I clean my rusty ass block, and then what paint can I use?
Elbow grease. Purple power degreaser, scrub and rinse. Any high temp engine paint is fine. However there is one step in preparing any cast iron component that needs to be taken, otherwise the paint will start flaking in short order. Cast iron is very porous and even if it is dry to the touch, it still contains moisture that needs to be removed. Enter the common propane torch. Simply play the flame on every surface of the block, head or manifold. You will see the moisture precipitate out of the metal. Additionally any remaining grease or oil will be burned off. Once the metal is truly dry you can paint and it will wick into the cast iron ensuring complete adhesion. If you leave the moisture in the metal it will precipitate out during normal heat cycling and cause the paint to flake. Light surface rust is okay, use a steel brush to remove anything more.
4. Media Removal: I inadvertently hit the interiors of some valve covers with aluminum oxide media. (Now I read cek's advice about avoiding this). What does anyone suggest about removing the oxide media? Hot dip power wash? Gasoline? Pressure washer?
Aluminum oxide....on an aluminum part.....bare aluminum oxidizes rapidly when exposed to oxygen forming......aluminum oxide....with embedded aluminum oxide....wash it off, scrub it with a brush....it's trapped and not going anywhere.
Powder Coating: Should one powder coat the Oil Pan and Differential Cover or is this not recommended due to heat dissipation issues?
Theoretically yes, practically? No. Just drive faster to compensate. Not an option on a VW so don't powder coat that engine.
Mike W.
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Post by Mike W. »

turbodan wrote:I'm on the other side of the fence on sealant. I have had excellent results using nothing but a gasket. Water pumps, oil pans, timing cases, etc. With clean, undamaged sealing surfaces an ordinary gasket is perfectly sufficient. Sealant can be good for filling imperfections but should not be used in place of proper surface prep.
My experience is areas like the timing cover will leak in time without sealant. Water pump and stat no, but #3 will help keep it leak free and make replacement easier. Much easier.
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Post by danc »

STICKY!!!
tig
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Re: M30 Engine Rebuild Tips & FAQ

Post by tig »

FWIW, and in the "I wish I had known this before" department, I was just reading the Haynes BMW 3- & 5-Series
Service and Repair Manual
since it's available online. "Chapter 2 Part B: General engine overhaul procedures" has TONS of information that would have lowered my angst level greatly if I had read it. Not all of it is specific to M30 motors, but much of it is.
athayer187
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Re: M30 Engine Rebuild Tips & FAQ

Post by athayer187 »

Another note - the Haynes manual has one of the most comprehensive sets of clearances and original specifications all in one place.
BuzzBomb
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Re:

Post by BuzzBomb »

cek wrote: Q: If I need to put splices in my wiring harness what's the best splice technique
A: If you want reliability use high quality non-insulated butt/barrel crimp connectors with a quality crimp tool. Unless your technique is perfect, soldier is too prone to failure.

Image
I just noticed this and its important to note:
DO NOT use the combo in the photo above. Yes on the connector style, but those crimpers are specifically for "Weather Pack" style connectors, not round connectors as pictured. The crimp will be inefficient. The correct crimper will be a round seat on one side and a point on the other, to indent the non seamed side or the barrel. Image
tig
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Re: Re:

Post by tig »

BuzzBomb wrote:
cek wrote: Q: If I need to put splices in my wiring harness what's the best splice technique
A: If you want reliability use high quality non-insulated butt/barrel crimp connectors with a quality crimp tool. Unless your technique is perfect, soldier is too prone to failure.

Image
I just noticed this and its important to note:
DO NOT use the combo in the photo above. Yes on the connector style, but those crimpers are specifically for "Weather Pack" style connectors, not round connectors as pictured. The crimp will be inefficient. The correct crimper will be a round seat on one side and a point on the other, to indent the non seamed side or the barrel. Image
Source? I bought this as a kit, I think.
BuzzBomb
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Re: M30 Engine Rebuild Tips & FAQ

Post by BuzzBomb »

Would not have been a kit. Unless you are busy doing weather pack connectors, that crimper is not common at all. Hardly anyone carries it, and they are more pricey than the pictured style.
They are around $50 for a decent one.
Delphy who originally came out with the weather pack style connectors sell their tool, similar to yours for around $250.
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