I’ve been reading about changing the valve guide seals on an R56 Mini and need some explanation. At 66,000 miles, I prefer to leave my engine in the car and not replace the timing chain. I think the process is something like this but appreciate any clarification or correction.

Thank you,
Peter
***************************

Particularly, what do you do with the timing chain while the cams are out of the head?

Removing VANOS

1. Rotate crank to 90 degree position and install flywheel lock tool (11 9 950), (what is this 90 degree position?).
2. Remove the valve cover, (including sensors, spark plugs, etc.).
3. Remove upper timing chain slide rail from top of chain.
4. Install cam timing position locking tool.
5. Remove timing chain tensioner.
6. Remove timing chain guide rail bearing bolt.
7. Unbolt VANOS units, remove timing chain from them, and remove them.

Removing Cams and rockers

1. Remove cam timing position locking tool.
2. Slowly remove cam bearing locking bolts simultaneously until cams come out.
3. Unbolt rockers and remove them.

Changing Valve Guide Seals

1. Start with cylinder 2 and feed a (undetermined) length of rope into cylinder.
2. Remove crank locking tool and rotate crank to put rope pressure on #2 intake and exhaust valves.
3. Install giant tool on head and start with compressing cylinder 2 valve spring retainers, remove the keepers, and remove the retainers and springs.
4. Hand pull off the old valve guide seals and push on new ones.
5. Installed the valve springs and retainers and then use the compression tool to install the keepers.
6. Repeat for cylinders 3, 1, and 4.

Installing the cams and VANOS

1. Rotate the crank back to the 90 degree position and lock into place with flywheel tool.
2. Install rockers.
3. Set cams roughly into place and loosely install cam timing tool.
4. Tighten cam bearing caps simultaneously.
5. Rotate cams slightly to align and tighten cam timing tool.
6. Bring up timing chain and wrap around VANOS sprockets, (Is the timing controlled by the flywheel tool and the cam timing tool?).
7. Tighten timing chain guide rail bolt.
8. Using new bolts, tighten the VANOS units to the cams.
9. Tighten the timing chain tensioner.

Wrap up

1. Double check cam to crank timing (somehow).
2. Install the sensors and spark plugs.
3. Install the cam cover.

 

Have you read about timing chain problems on these? If the timing chain hasn't been done before, and depending on year of car, might be best to do this while you're at it.

90 degree position is where the pistons will be in the middle of their stroke. Not the top, not the bottom. You can put wood dowels in the spark plug holes and make sure it goes in the same depth. Also, the special cam position locking tool, the position the cams need to be in for that to go on, will give you an idea of when you're coming up on the crank lock pin position.

I've heard of this rope trick on other engines, not on this one. I THINK most people would use a special fitting in the spark plug hole for an air compressor and keep the valves lifted that way. Either way isn't foolproof I suppose. I don't like the idea of rotating the crank and cams not attached to each other. Seems like asking for timing trouble. But I'm just learning these engines too.

Good, you caught the new bolts on the vanos. If you pull timing chain out, the hub bolt is a replacement item as well, and front crank seal.

When the crank is locked in its special position, and the cams are locked in their special position, and you put the chain on with tension in right spot/sequence, supposedly it will be in time. For $32 for 24-hour access, BMW TIS system will give you instructions on how to do timing, check timing, adjust timing.

What I'd do with the timing chain while loose is zip tie it to something so it can't fall in, BUT, sounds like you're going to be rotating the crank so that's out. Maybe stick a long bar across the engine bay so the timing chain can rotate freely over it but not fall in?

I stress, I try to help, but am also just rebuilding this motor for the first time and very much a newbie.

 

Jawilli6:

Thank you for your input as I’ve done valve guide seal replacements many times but not on an N-16 engine.

Timing chain problems?

I’ve got a Mercedes diesel with 250,000 miles and never thought about its timing chain and yet you say the N16 engine should get a replacement at 66,000 miles? I’ll do it if it is justified but that seems like a bizarrely short lifespan for a chain.

Rotating crank and cams not tied to each other?

Not really, as the cams will be removed during the valve guide seal replacement. The valves will all be completely closed.

BMW-TIS

I’ll have to figure this out as I’ve been using a Bentley manual which has been a godsend; however, it surprisingly does not cover these procedures at all.

Thanks,
Peter

 

Very good, then you'll probably be ok.

Timing chain problems, yes. Do a search on here or google and you'll find more info. I think a lot of it had to do with a bad tensioner design that leads to chain stretch or guide wear. People talk about the tell-tale rattle of the chain. I think it was a recall for certain cars/model years. I'm the second owner of my car which has an N18, turbo version of your engine. The previous owner had the timing chain done with the new style parts at 70k miles. Please do your own homework, your model and model year may have the latest design parts. I do not know.

It had sounded to me like you'll remove the chain, and then be rotating the crank to compress the string you lowered into the cylinder. Perhaps I misunderstood something.

You're in much better shape than me, since you have the manual. I've only had this forum for guidance until I found TIS. But TIS is a very by-the-book way of doing things. TisUI (bmwgroup.com) You have to create an account and pay a fee to get access. It's a little tricky to navigate. It sounds like you have a good handle on things. Probably won't need to use this unless you get into trouble.

Good Luck. Hopefully someone more knowledgeable will chime in for you.

 

Blind leading the blind? Ha ha. It seems that we are leading this story and neither of us has done a Mini seal replacement.

I’ve never been one to be afraid of doing something for the first time.😜

 

When changing the timing chain on the N16 engine, the Bentley manual says to support the engine with a special support and removing the main support but nobody mentions this. How do you support the engine while removing the chain tensioner guide bolts?

 

There is yet another special tool that you attach to the front of the engine; If I remember correctly, you have to remove the alternator and attach the special tool to the engine block.

I don't have the tool; I just use a floor jack and a piece of wood and support the engine from underneath (oil pan).

 

Super. Floor jack it is.

To do this job, I have already purchased:
1. Cylinder pressurizing hose.
2. Cam timing tools
3. Spring compressor tool
4. Valvotronic spring tool.

I’m not eager to keep buying tools so happy to use the floor jack. At this point it may be cheaper to take it to the dealer.

Peter

 

Oh, and today I bought a crankshaft holder tool. The dealer is looking better all the time.

Peter

 

I wish you live near me, so I could borrow or rent all those tools once you are done.

 

Yes. Me too. I also wish they sold all of the tools as a set rather than five different cases.

Peter

 

I just completed this job about a month ago. Not bad once you get started. If I could offer some unsolicited advice. Have an extra collet or two. Use grease on the end of a small flat head driver to place the collets in place. Use the compressed air method over rope method. Get comfortable with your spring compressor tool and make sure you have it well balanced. Place the collets onto the ribs of the valve. Make sure flywheel is locked when reinstalling. BLOCK all ingress points on the head. I lost a collet somewhere.

any other questions feel free to ask.

 

Sounds like valuable information. I’ll probably be doing this job next week.

Thanks,
Peter

 

good luck!!!!

 

Sheesh. replacing valve guide seals and the timing chain was more difficult than I expected. I thought it would take a dealer mechanic a couple hours and take me a whole day. Wrong!

I finally finished on day five. I bet three whole days were spent on the complex Valvotronic variable valve lift stuff. Yikes.

I also struggled with removing the timing chain cassette. I didn’t catch where it said the oil dipstick goes through the chain guide. I probably lost three hours with that one detail.

I did purchase 1. Valve spring compressor tool, 2. Valvotronic spring removal tools, 3. Timing chain timing tool, 4. Cylinder pressurizing hose adapter, 5. Front lip seal insertion tool, 6. Crank shaft turning tool.

Also, I am retired so a full day is probably only 6.5 hours.

But it is back up and running smoothly,👍

Peter

 

Well done!!!
Would you be able to rent out those tools? Please PM me with details.