Last weekend, my 2006 Mini Cooper S with just over 30k miles ate its #1 piston. If you'd like to follow along as I go about resolving the issue, check out my Mini engine blog at http://r53mini.blogspot.com

The drive train is stock except for a 15% reduction pulley.

I have a bunch of questions:

1. Has anyone else had this problem?
2. Does anyone have a spare, good OEM piston that they'd like to sell me? Seems Mini only wants to sell complete sets for an outrageous sum.
3. I'd really prefer not to have to rebuild the entire bottom end. The cylinder wall has a couple of small scuffs. Think I can get a decent result by simply adding a new OEM piston and rings?

Before you ask, "no" I didn't "money shift" the car. Yes, I was participating in high-performance driving event on a closed course. Yes, I have participated in many, many high-performance driving events in the car in its relatively brief life.

In any event, I plan to keep the blog up-to-date and thought some of you NAM participants might find this interesting.

 

Not me, but I am always fascinated by folks that can tear a car apart with confidence they can get it back together, again. I'm a pilot and folks are always giving me unearned respect for horsing an aircraft around the sky. I give respect to the mechanics.

 

I'm sorta in the same situation you are in. Recently I was getting a dyno tune and my #1 plug was faulty. The electrode from the plug fell off and it cracked an exhaust valve.

Seeing that I have just a tad over 100k, I'm doing a complete rebuild with one of Jan's engines along with a stage 4 clutch and cusco LSD.

 

I have a used piston.. pm for the cost!! cool??

#4? 15% pulley?? stock heat range on the plugs??? That is HOW I have extra pistons!! LOl. Not my 06 but a friends 04!! I told him about the add'l boost and the need to upgrade the colder spark plug, the Dyno showed him "just a bit" on the lean side, and yet he just kept "running it" Took out the ring lands on #4 as you did thru detonation.
I always suggest.. colder plugs!! If there is exhaust/cam.. blah..blah.. and NO tune available... then It has to be a water -meth system to keep it all together..yes!!

Cool Helper!!

Just me..............................

Thumper

 

where do you get pistons with the cool flat spot? for air extraction ? had same issue on #4 but got lucky ; no rebore . will need soon though . any idea as to the cause? high g's right handers?

 

Thumper: I think I am going to try some aftermarket pistons, but I am glad to know you have some OEM ones. Thank you for chiming in. I'm going to post a new thread on piston suggestions.

One of my neighbors came by with his father today. His father has run a repair shop for decades. He took a look at the block and thinks the damage to the cylinder is minor and should clean up with honing. My plan now is to replace all four pistons, rings, etc. without reboring.

Yes, I was running the stock plugs and stock injectors. I will definitely change the plugs and may swap the injectors too.

By chance, has anyone found a supplier for crank and rod bearings? The prices from Mini are outrageous!

 

How do these prices compare?

http://new.minimania.com/web/Item/NMK5007/InvDetail.cfm

http://new.minimania.com/web/Item/NMK5003/InvDetail.cfm

 

$600 in bearings alone No wonder why abarks said the prices are outrageous!! If MiniMania is asking that much how much could the dealer be asking......holy crap!

 

A 2006 with 30k? Did you first run it to the dealer to see what might be covered under warranty?

 

very interesting

 

man. you need to pm k-huevo he recommends to avoid the mains if you dont need um cause it's a split case and has to come together perfect with perfect amount of sealer etc. just do the rods if you can . the rod bearings from mini weren't that bad in price .

 

First, I haven't contacted Mini even though the car is only 8 weeks past warranty and less than 36k miles. I'm not sure what they would do for me, quite honestly. I figure, best case, they'd sell me a new engine for half price. . . which would be $4k I guess. I can pop in a set of CP pistons for less and (I hope) have a stronger motor. Perhaps they would sell me some of their outrageously priced bearings for half-price. That'd be nice. Maybe throw-in a head gasket.

My plan is to attempt to hone the cylinders with the block in the car and the crank in place. I know - sounds nuts, but I'm going to give it a shot.

Has anyone out there ever attempted honing with the crank in? What was your result? How'd you protect the crank from debris?

 

I'd think carefully placed plastic grocery bags will protect the crank from metal dust. I've never done this before though.

 

Sounds like a really good opportunity for things to GO SOUTH at surprising speed!!

 

For an '06, the warranty is 50,000 miles. 36,000 is for the free servicing/oil changes.

I bought my MINI used, the engine had a faulty cylinder but it lasted about 60,000 miles before I had the engine rebuilt and bored out with CP pistons...then the engine mounts broke and I destroyed my new clutch.... Thankfully I'll have it running again by next week...can't wait to be driving it again.

Richard

 

Have u considered after market bearings?

such as ACL for example..

i've seen them used with great sucess in 1,000+ HP applications

u do realize tho that forged internals do wear out faster then them oem counterparts

so u will have a "stronger" motor.. but the rings with wear out faster...

so if ur not planning on big HP numbers, u might want to re-consider ur course of action

 

Photos can be found here https://www.northamericanmotoring.co...on-begins.html and I’m aware of it being done on a few other cars. If the scuffs are deep enough you may need a line bore with the block out of the vehicle.

The OEM MCS crankshaft, connecting rods, and pistons are all forged. Explain reasons for that statement please.

 

yeah ; that's how i did it . plenty of room just remove the squirters first so you dont contact them .

 

no dust .you use liberal amounts of oil while honing; then wash everything down , the mains are not exposed ; just the rod journals.
.

 

Shows how much I know... never honed an engine before, though.

 

k-huevo: Thank you for the link. I feel much better about my honing after seeing photos of someone else having done it.

herbie: I haven't removed the squirters. Do I need to mark their exact locations or do they go in the correct position only?

Anyone know what kind of pistons those are in the turbo install thread? I'm planning on CPs at this point.

 

You do have to remove the squirters. Note thier positioning and clearance in relation to the piston skirt. I wrapped oily rags around the crank and put a cardboard cutout at the bottom of the cylinder to prevent contact with the crank.

Pistons, try Hubie Fuh. He has custom JE pistons and is very helpful. I should have a set sometime this week if you are interested in pictures.

 

Just curious, driving the car for 30k with a lot of track time according to you, how often did you change your oil ?

 

I find ball hones tend to take out too much metal, I recommend one of these instead if all you're trying to do is clean it up. Wipe down the cyl walls with solvent or spray with WD40 and wipe repeatedly, then for your final check to see if the bores are clean, wipe fresh oil in the bores with a clean hand then use a white towel or paper towel to wipe out the oil - if you get anything black or even dark on the rag, it's not clean - clean it some more. Do not run the hone into the rod journals as you move it up and down, move it quickly enough to try for a 45* hone mark on the walls when you're done.



This type hone keeps the stones paralleel to the bore, and is adjustable for tension so you can remove ust enough metal, you can also get a variety of stones so you can get the right grit.........it's a KD hone available at most parts stores (IE: NAPA)

 

The 'dingle ball" "glaze breaker is the best.. all you want to do is lightly scuff the cylinders.. the Moly ring set that is used, likes a smooth finish ( vs the older ring set that had to be ruff!!) Actually you can use a 100 grit sand paper and your hand!! Go around the cylinder..not up and down!! like I said all you need to do is "break the glaze" , cool?? You can usually rent a ball type glaze breaker from a auto rental shop.. you will need to get close to the bore size!!

Cover the rod throws on the crankshaft as stated... and use a good solvent to clean the cylinders.. as stated above... I wouldn't WASH the cylinders.. just use a damp rag. Break clean, is aways good... again.. when done and all is clean... blow dry/ oil up / wipe down... re oil and assemble!!

Rod bearings here in N Fl are $300.00 a set!! The last engine I o/h cost the customer 700.00 for bearings!! OUCH!! with the ring set.. close to a grand!! I also agree.. if the piston is bad... then no need to go after the main bearings..!!

There are some 11 sec MINI's on NOS and ALL stock internals, along with a few 300 HP boosted engines... these engines are solid, it "aint you dads Oldsmobile!! " Have fun... yes??

Just me.................................

Thumper