Cylinder head

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adika
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Cylinder head

Post by adika » Tue Dec 03, 2019 7:57 pm

Hello everyone, I was changing my spark plugs and 2 snapped right in the engine. I tried using an extractor but it seems they are badly rusted in there. I believe my only other option is to remove the head and have the taken out somewhere, not really sure tho. Has someone removed the cylinder head and has posted clear instructions on how to do it? I will be changing gaskets and stuff while I'm there too. Any help would be appreciated.

PatinaBeforePolish
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Re: Cylinder head

Post by PatinaBeforePolish » Thu Dec 05, 2019 4:48 pm

Always surprises on these somewhere around 40 year old cars. You can get carried away with the "while I'm in there" approach and may find a few more surprises. Hopefully it's not your only car...

Removing the cylinder head is pretty easy, just a matter of removing intake and exhaust components and keeping track of wiring connections and bolts and washers. I've read some accounts of leaving the manifolds on but for me, the head's heavy enough by itself. I suggest taking pictures and drawing diagrams. First step is to drain the coolant from the block. The 19mm (I think) plug is at the rear of the engine underneath the exhaust manifold. I'd drain the engine oil as well. It's tempting to remove the hood for easier access, but they're a real PITA to reinstall.

The upper timing chain cover needs to come off, removing the distributor first. The upper timing cover is secured in both a horizontal and vertical plane. The 2 vertical 10 mm bolts sit between web castings in the cover. That area needs to be free of gunk and dirt in order to fit a wrench or socket. The one on the passenger side can be tough, I recommend a thin wall socket and a shorty ratchet or a short 10 mm wrench as longer wrenches will hit the radiator. The bottom of the upper timing cover gasket is part of the head gasket and replace the gaskets on each side of the cover. There's a correct tightening sequence for the cover reinstallation but I'll need to reference the manual. Someone else know?

The timing chain tensioner at the top passenger side of the lower timing case needs to be removed. It's spring loaded and will pop out in an oily mess. Once the upper timing case is off, you can remove the cam sprocket by removing the 4 bolts. There are 2 securing plates, 1 for 2 bolts, that likely have tabs bent around the bolts as a safety fastener. The plates are NLA and I'd love to know if anyone has found a substitute. Otherwise be careful as you'll need to reuse them, just make sure to bend the other side.

In addition to fixing the head, while you're in there you could: Send the injectors out for a cleaning, new injector hoses and gaskets, new gaskets for intake and exhaust, new water pump, thermostat, motor mounts, water hoses and clamps and I'm sure I missed a few things. All this because the damned sparks plugs corroded in the head! I'm not sure if the head bolts are stretch bolts and cannot be reused but I'd order new ones with washers anyway. With the head off, position cylinder 1 at top dead center and make sure cylinder 1 on the head is set to compression (both valves closed) before you reinstall. I'm interested to hear other opinions about replacing the timing chain while you're in there. That involves removing the crank pulley to remove the lower timing case.

An experienced tech could do this job in a few hours if they were using a new head - it would probably take me a month of Sundays. I'm sure others here have more tips, tricks and corrections to this post to make the job as painless as possible. Search engines and youtube are your friends.
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79 528i
01 540i
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maybeillbuyit
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Re: Cylinder head

Post by maybeillbuyit » Fri Dec 06, 2019 4:20 pm

Excellent write up there Jon. I would add that as far as I know the headbolts are not stretch bolts or "torque to yield" and can be used again. I used mine again without any problems but if your fussy you can buy new ones. From what I've read most guys do the timing chain while in there . I didn't on my beat old e24 as I didn't really know what kind of shape the engine was in. I would on a nicer car though. Its easy to keep adding stuff. You could raise the engine and remove the oil pan and rebuild the oil pump while in there as well. Especially if the pan is leaking like most.
1977 530i another project
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adika
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Re: Cylinder head

Post by adika » Wed Dec 11, 2019 7:51 pm

Thanks for the info. Yeah I will be replacing a lot of that stuff while everything is disassembled. Do you guys know in what order I need to remove the head bolts? I want to avoid warping the head. Thanks again.

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keehn
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Re: Cylinder head

Post by keehn » Sat Dec 21, 2019 11:13 am

Adika,

Here's a screenshot of the official "blue" manual:

Image

Third down is the exact instructions to install the cylinder head.

The torque specs:

Image


Hope this helps!

Mike

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keehn
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Re: Cylinder head

Post by keehn » Sat Dec 21, 2019 11:28 am

Adika, one more thing:

BMW's torque specs in the blue book seem...weak, so I did a little reading on M30 engines in newer E34 models (since it's essentially the same engine through all of these years.) Sure enough, the torque specs recommended are tighter than BMW's original specs, as shown below:

Image

Hope this helps as well!

Mike

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Lock
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Re: Cylinder head

Post by Lock » Sat Dec 21, 2019 1:51 pm

Just wanted to add, even tho they do mention it, cleaning and drying the headbolt holes before reassembly is really important with M30 motors, not just for correct torque specs but also to avoid the block cracking. I had to scrap an e34 535i because the block was cracked due to whoever replaced the head last not cleaning out the headbolt holes.
1979 528i 5-speed conversion G260/6, Motronic 1.3 179
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keehn
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Re: Cylinder head

Post by keehn » Sat Dec 21, 2019 6:48 pm

I second Lock's suggestion. One other important reason to ensure the thread holes are dry is that any oil can cause "hydrolock." The oil doesn't have anywhere to go, therefore you will get false torque readings, and when the oil heats up, it wants to expand...hence, cracked block.

Merlin
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Re: Cylinder head

Post by Merlin » Mon Dec 23, 2019 12:43 am

The head bolts are reusable however the rocker shafts and arms are not. Yes people get away with it but it’s a big risk. The biggest issue is when you pull the head you will need to surface it thus strip it.
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adika
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Re: Cylinder head

Post by adika » Wed Jan 01, 2020 11:15 pm

I appreciate all the info and help. I have taken it off and now its time to clean it to get it reinstalled.

Thanks again

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528i-1981
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Re: Cylinder head

Post by 528i-1981 » Thu Jan 02, 2020 5:26 am

Great news. Were you able to get the snapped plug out yourself from below, or did you take it to a shop?
(oo=00=oo) Eric
1981 528i Manual

adika
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Re: Cylinder head

Post by adika » Thu Jan 02, 2020 10:38 pm

I had a mechanic friend of mine take it out. It was so stuck in there that we had to drill it out. Took a long time but we managed to do so without ruining the threads which I am thankful for.

The next issue i predict I may have is the injectors not sealing properly to the manifold. The seals between the injector and manifold are very old and one even cracked on me. I cant seem to find the anywhere which is quite frustrating but Ill deal with it when i get there. :D :lol:

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Lock
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Re: Cylinder head

Post by Lock » Thu Jan 02, 2020 10:59 pm

I was just talking about this with Eric the other week as we're both doing injector work. You can get parts here:

https://9fc49591-6086-4288-b49e-0823e99 ... 9c7e00.pdf

You'll want page 14, "Bosch Hose Type Injector" parts and you're probably after the lower seal #3-107. I believe Eric bought these exact parts too.
1979 528i 5-speed conversion G260/6, Motronic 1.3 179
1980 Honda CX-500

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528i-1981
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Re: Cylinder head

Post by 528i-1981 » Fri Jan 03, 2020 8:05 am

Yes, that's correct. They're really a reman operation, but they'll sell one-off retail to individuals. FYI, the fuel line sections they sell for the injector-to-rail connection (at a premium) are nothing special. Use genuine BMW fuel line and cut the sections yourself. Their components appear to be high quality across the board.
(oo=00=oo) Eric
1981 528i Manual

PatinaBeforePolish
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Re: Cylinder head

Post by PatinaBeforePolish » Fri Jan 03, 2020 6:06 pm

I've used this service multiple times. Quick turn around, installs new rubber lines and only $17.50 plus shipping per injector. He also provides a before and after flow chart.

https://www.mrinjector.us/

And from experience while you're in there you may as well order new seals, the insulating tabs, bolts and washers for peace of mind. They're all still available from the dealer
78 F150
79 528i
01 540i
86 944
08 X3 don’t judge me it’s there to preserve the others

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