Getting ready to tackle a valve seal replacement job on a n14 r56 MCS. I’ve seen a few different threads where people have asked questions but wondering if anyone knows of a step by step DIY? I think I have the big picture but don’t want to miss any crucial steps. Also finding torque values in one place seems to be a tad more difficult.

 

Why do you want to replace the valve seals? Do you see a puff of smoke from the exhaust when you first start the car for the day?

You best bet is to pay the $30.00 / 24 hours at BMW/TIS and download every procedure for your car that you can. Mitchell1 also has BMW/MINI support.

 

I had the car at the mechanic for an AC tuneup and while it was idling for 30min or so the car would blow smoke out the exhaust on throttle. I’ve seen it before on cold start if the car sat for a week or so. Recently confirmed the smoke was blue which led me to the seals.

good call on the bmw tis. I’m definitely more visual so was hopeful of a video or higher res photos but that might be my only choice. I just posted a new thread but I may be pulling the whole head but that’s a different story.

 

I am pretty sure smoke after a long idle is related to the PCV system. And N14 engine is know for having issues with PCV. I would look at a replacement valve cover and walnut blast.

There was a member that did a valve stem seal replacement with the head still installed… I’ll have to see if I can find it…

 

This is the thread is was thinking of:
https://www.northamericanmotoring.co...placement.html

 

Thank you for the info! Are there any distinctive traits that would indicate valve stem seals? Car only has 65k but the local mini mechanic here in OC/LA suggested the replacement.

I ordered a similar tool as the one in the link, as well as a Lisle 36050. Any thoughts on one vs the other?

 

I would suggest a little more diagnostic work to determine the cause of the oil consumption. Dry/wet compression checks for starters, and a check of the PCV system to make sure your crankcase pressure is not above spec.

Don't forget that under the valve stem seals are the valve guides. If those are shot, changing the seals may or may not help.

 

i did not know about the valve guides. How can one tell if they are good or not? I did run a leak down test after walnut blasting and I have a big leak of air out of the intake ports. Car has been pulled apart for about a week so not sure if this is even a reliable test.

 

Performed correctly, leak down is always a reliable test; sometimes we just don't like the results because it means we have some mechanical repair to do. And, on MINIS, that's expensive!

Get a fiber scope and look down the intake port, you probably have a dropped valve seat. Here's a picture of what I found with 98% leakdown on cylinder 1. N12 engine



Here's what 23% leakdown looked like on cylinder 4 ... same engine.

If you do have dropped valve seats make sure you get all of them changed or you will be taking the head back off later to fix the next one that drops.

While the head is in the machine shop, the machine shop will tell you if the valve guide and springs are still good, and give you a repair estimate if they aren't.

 

I just completed the valve stem replacement. Not too bad once you get the hang of the tool. I did lose one keeper somewhere in the engine head. I assume it went down one of the oil return channels. We'll see if that comes back to bite me in the *** later.

A couple of notes from my experience:

• You might as well do the timing chain while you're in there. All my guides looked good, so I didn't think it would be necessary on initial thought. I decided to do it anyway and discovered that my timing chain was about half an inch longer than the replacement chain. I was also slightly out of time. I suspect this was what caused my poor leak-down results as well. I went with the WMW cryo-treated genuine kit supplemented with a felpro crank seal.
• You must remove the cam caps, rollers, and cams to get to the valve spring. From here, use a valve compressor to compress the spring and remove to keepers. Using a magnet made it easier. I have a N14, but a N18 requires an additional unique tool to complete the job.
• The Amazon spring compressor tool works fine, but I needed to add a few spacers to the mounting hardware.
• Compress the spring and hold it for dear life until the keepers are removed. If you release it early, hope it flies far, far away. I learned the hard way to plug my holes and crevices.
• Reinstalling the keepers is easier by using a small flat head with some grease to hold the keeper until you set it in place. Compress the spring as far as possible and put the keeper into the valve grooves. Do not attempt to place it and let it "fall" into place. You will lose it.
• Valve seals were shot, and I replaced them with Felpro from WMW. I could see and feel the difference in the gasket size between new and old.

The smoke from the exhaust is now gone. I have a 2010 with 65k miles. The timing chain tensioner was replaced once under the class action, but I suspect the chain was never changed. These two repairs have made my car feel like new again. New valve cover and carbon cleaning are also contributing, I'm sure. My biggest culprit was the timing being off. Not a bad idea to check for all cars. Place the locking pin in the flywheel with pistons set at 90 degrees. Line up IN and EX text on cams. and slide the cam locks over the ends. If the tool fits perfectly, you're good.

 

Great report. Are the valve guide seals and timing chain a problem with the N16 engine as well? I'm getting an R56 tomorrow and was curious.

Thanks,
Peter