Hello,

Novice mechanic guy here, I bough this MCS with 115k miles intending to do a head gasket and timing job.

I remove the timing and it didint seem to be broken or even out of time since my cam locking tool bolted right on and sprockets weren’t crooked. Chain seemed decent no noticeable mishaps but I haven’t compared to my new one from ecs kit.

I’m removing the head knowing I will see quite a bit of
carbon blow by because of

1. White/gray smoke when running.
2. I could see through spark plug hole
3. Dirty intake valves

I’m looking down at my head gasket and block,

- head gasket has several cracks but not completely severe
- my rings and pistons look uneven next to each other around the edges. The shiny metal part peaking around the top of the piston I believe is the piston ring, it doesn’t look like a perfect circle all the way around the piston. On cylinder 1 of my added pictures you can see on the backside(when facing front of the car) the shiny metal ring is more visible vs around the piston nearest to me. On cylinder 2 you can see its opposite. On backside ring is not visible vs nearest to me it’s more visible.

Does this mean I need new piston rings & bore?

What else would need to be done besides having a machine shop resurface the faces of the block (might as well give them my head too) install wider pistons, bore, and rings?

I wanted to keep it close to stock power (I got it cheap with a catback exhaust) so I now that new pistons might be considered it makes me question what’s the point of going to stock power since I believe I would need a tune to accommodate the bigger cylinder size.

tune needed after bore?

when bought it had lower than threshold compression and I drove it In limp mode ~40 miles. This test made me hope it was mostly timing needing to be done since if it were the head gasket it would more than likely to have severer compression on a select number of cylinders vs all cylinders being in the same general compression. Plus I know the fuel pumps are pretty bad so I've decided to fix that after I got to see my block and pistons. It had trouble on cold starts and when pump wasn't primed in some time. I intend to test to decide if its either in tank pump or under hood pump after my block is ready.

if I do need to fix the pistons and cylinders would it make more sense to buy a whole block if I’m trying to stick to stock power. Whole block would have to be in decent shape rated by a machine shop.

new block?

i haven’t testing most of the electrical yet, I think the timing could be out because of camshaft position sensor. But I don’t think that would have effected my pistons to the point to where I need new rings.


i don’t have much space so even if I had to part it out It would be as difficult for me to store everything than just get a new block or new pistons.

Car interior is in amazing shape and has great interior packages with Harmon kardon. Biggest reason why I wanted to fix it up drive it for a little and sell if the engine didint need too much.
plus it’s a manual.

i could probably sell the head, transmission, xenons, original mini 18’ rims plus interior and trim and get my money back but I want to experience the mini lifestyle in BRG🏁. Never was looking to soup it up, just fun car because I have a daily.

This has also been an extreme learning experience due to this being my biggest mechanic job yet. I don’t mind doing the harder mechanic work I just dont I don’t have the tools for doing any surfacing or boring. My only other experience is an older jeep clutch job and oil changes. Makes it hard to admit defeat and get rid of this knowing it’s a bad block vs using it as a donor car for myself or part out.

i will add more images of what I might be helpful

All help is appreciated!

My BMW Foxwell codes are:
2789
2bee
2c01
2ef7
2efe
2eff
2f00
2f01
2f02
300c

EDIT: I've added better pictures of my bore and walls with their crosshatching. Is it reusable without a bore and just do 3 piece piston ring set?

 

Honestly, everything looks good. I'm not a professional mechanic or anything, but I don't see an issue. Maybe someone with more knowledge can give better insight. Especially after 128k miles. I can't tell from the sideways photos of the bores, but the overhead looks good. The piston rings aren't supposed to touch or be a perfect circle around the piston. So them not being connected is the way they are supposed to be. As far as your codes, I had no compression on any cylinder when my timing chain went. And my timing was in spec. But the chain was so loose when I pulled it out compared to the new chain. So I would definitely replace that since you got it, do a valve cleaning job even though I believe the N18 don't get as bad as my N14. And then get new head gasket, plugs and possible coils. Valve cover and gasket. Slap it back in and see what it does. Hope this helps!

 

Well, it's too late now to troubleshoot the cause of the misfires. I would have done that before I pulled the engine, but now that you have the engine out, you might as well take it to the machine shop and have the engine rebuilt; components that are within spec can be reused. With that many miles, you are going to need a new set a valves (yes all of them). A proper leak down test would tell you where your compression was going I.E. past the piston rings, valves, or head gasket. That information would have been useful.

Based on the faults you posted; low fuel pressure stands out a significant problem and will cause misfires; the "can't measure airflow" fault also stands out as it can also cause misfires. Camshaft sensors don't set timing; they only report to the DME where the camshaft is; timing is set by your timing tools; they hold the relationship between the camshafts and the crank when you install the timing chain. Make darn sure you have an quality torque wrench with angle. I have seen timing slip because the VANOS sprocket bolts were not properly torqued. If you have a Camshaft sensor fault, you have to troubleshoot to see if you have a timing problem (mechanical) or a sensor problem.

Leave the machine shop work to the professionals with the experience!!! If you don't you will be very disappointed when you fire it up for the first time. MINI cylinder heads are notorious for dropping valve seats; so when you take the cylinder head to the machine shop make sure you tell them to "stake" the valve seats because they are known to drop. A good machine shop will know what I'm talking about. Also, I've pulled two MINI cylinder heads and in both cases the heads were warped. Both had to be planed by the machine shop. Keep in mind when you are putting this back together, the cylinder head mating surface has to be perfect.

When the head goes the machine shop, you'll have to tear it down first. I made a video for re-assembly (special tools required). Watch it backward for disassembly. ;-) Do not attempt to take apart the VANOS springs on the intake camshaft without the proper tool; you will damage the cylinder head.