Article by: John Taylor with edits, comments, and photos by Yutaka Nakagawa and Sean.
Article applies to: all models with the M70 V12 engine.
Comment by Sean750: John experienced some intermittently tapping lifter noise with his ’89 750iL. He wrote a story about it , took some photo’s and gave kindly permission to publish it. If you want more specific information about how to remove the intake manifolds, see our section ‘intake manifold (v12)’. The nice thing about lifter replacement is that you don’t have to remove the camshafts. But you need a special tool to compress the valve springs (an ordinary spring compressor won’t do the job). John is using a home-made tool to compress them, but Midlock (no affiliation) can provide a special tool for this procedure.
John: I was quoted 4500$ Canadian at the stealership to fix what I thought was one intermittently tapping lifter.
I used a couple of engine flushes with no joy. I got the 12 lifters from JAC for $17us instead of the $78can the stealer quoted. I dug down to the valves using the Bentley book, taking pictures and notes.
Engine cover, MAF’s, air boxes, injection harness and injector rails removed:
Comment by Sean750: One intake manifold removed, now the other is easy to get to.
If you don’t replace the infamous intake gaskets, make sure you use some sealant (like Hylomar) when reinstalling:
Comment by Sean750: Both intakes are removed. I suggest you check the intake ports.
At this point you’ll be looking at the intake valves. If the valves are immersed in oil, there is a good chance the valve stem seals are worn:
Comment by Sean750: valve cover removed. Inspect the camshaft carefully for wear, indicating a banjo bolt problem of the oil sprayer bar (it seems that the ’88 and ’89 models doesn’t suffer from this problem).
A nice close-up, here you can see the rockers clearly:
John: I fashioned a valve compression tool, also shown in use below, to compress the valves.
This allowed me to slip the rocker out towards the spring, lift out and replace the hydraulic lifter, slot the rocker back through, and then getting the little spring cap on.
A screwdriver magnetized by stroking it with a magnet worked wonders.
The quickest took me about 30 seconds, the longest 2.5 hours (the tool slipped off the spring and jammed under the cam shaft):
I checked the head bolts and used loctite on the cam oil banjos and put it back together. Touch wood, 8000 miles later all is well.
This section was added on 4 Dec 2004: Sean750 received an extensive story along with pictures from Yutaka Nakagawa who replaced his lifters as well.
This is his story:
After spending a lot of time and spare parts from a scrapped car finally I managed to fire almost 12 cylinders of my car but it looked all 12 cylinders are not firing smoothly and with loud tappet noise.
I thought the loud tappet noise came from a faulty lifter so I read your article of Lifter replacement (article from John Taylor) many times carefully before I started work on my engine.
Since I could not find a lifter from a salvage yard, I bought one new lifter from the local BMW dealer. I decided to replace the faulty lifter, and after about 3 hours work I had opened the left bank valve cover.
I knew the noise was coming from cylinder #1 of left bank (close to radiator) by checking with a sound detector (Remark by Sean: you can also use a piece of hose and hold it to your ear):
What I found was broken rocker arm (drag lever in BMW part list). Cause of noise was not the lifter but a broken rocker arm and I realized my investment to lifter became just waste:
After I found this, I tried to make a special tool to depress the valve spring allowing to slide new rocker arm in/out as your article says.
What I did was modify a regular spark plug puller and weld screws to extend length and bend them to fit for the purpose.
I went to a car body shop and asked to weld it. I got there three times to get the final working shape:
I tried to use this tool with other normal valves for practice and found I could not slide rocker arm nor lifter out even when the valve spring was depressed to its minimum position.
At this stage I contacted a used car shop owner who I knew he had an BMW e30 318i and they were going to scrap it. I negotiated to get a lifter and rocker arm from that 318i and fortunately I got them.
I went to the shop with my tool to get rocker arm. After opening head cover of the scrapped car, I tried to use my home made tool with the 318i and again it did not work.
So I removed all nuts holding the camshaft bearing caps without touching cam chain sprocket part.
Now the camshaft is pushed up by the valve springs and I could get 6 lifters and 6 rocker arms by hand without using any tool.
Cylinder closest to cam sprocket was difficult but one lifter and rocker arm was taken with a little bit of compression of the valve spring. I got 7 sets out of 8 sets without trouble and I had enough spare parts:
Returning home, I decided to use the same technique as I could not sufficient depress the valve springs enough from the v12.
I unbolted all nuts holding the camshaft bearing caps, the camshaft lifts itself up, I inserted the new rocker arm and tightened the bolts again. This took me just 10 minutes.
This method looks to me a lot easier than to use special tool to change lifter or rocker arm. Hope this information helps some other people.
I am sure it could be done using properly designed tool. I think my tool was not good enough to do the job.
At least handle was too short so I needed fairly strong force to depress spring and since I used a spark plug cable puller, the distance of two pushing parts changes by the handles.
This gives some difficulty when I apply pressure by one hand and try to insert or take out rocker arm by the other hand.
Remark from Sean: the best method to depress valve springs with installed camshaft and cylinder head is using a special tool 13618 from Midlock (no aff.):
I have this tool myself and this is an excellent tool. If you are planning to use the method Yutaka describes, I must warn you that you must unbolt or tighten the bolts of the camshaft bearing caps equally to prevent excessive stress to the camshaft.