Yep, I'm a newbie. To the Mini life, but not to mechanics So, here's my story...

08 MCS 6MT with 58k miles. I'm the 3rd owner and have had this little turbo kart for a little over a month now. The most I know of the previous service history is a few receipts from the new clutch and from the new plastics/paint from being introduced to a shallow ditch. No idea on how it was driven or cared for, but the fluids were all clean and the car kept in immaculate condition. Bought it from a widow, whose husband passed away last year and she couldn't drive a stick.

Ran great for several weeks. I commute to work roughly 35 miles each way, all open highway. Ran it up to Baltimore and back -- couple hours each way. Then last week, I ran up to south NJ and back one afternoon -- about 2 hours each way, an hour of that solid running 75-80 on a closed highway.

When I got home, I noticed that it just didn't have the same level of power as before. More like it wasn't in sport mode, even though it was. Seems to hunt a little bit looking for a solid idle, but no problems starting or driving a bit. I haven't driven it much as I don't want to cause any other problems.

Troubleshooting so far:
Diverter valve -- looked fine, but had already ordered a GFB replacement DV and installed
Wastegate -- pulls back under vacuum, rod moves, borescope through the O2 sensor hole shows the valve closing under vacuum.
Tested vacuum at the wastegate line, vacuum pump working fine, ran a temporary new vacuum line from the wastegate back to the solenoid

No codes, no CEL
Doesn't rev quickly when blipping the throttle like it used to.

I do have the cheap USB OBD-2 reader and OBDWiz software, and the basics I have logged so far look normal, BUT, this would be my first crack at a Mini and certainly not familiar with the nuances of such a rig.

Would appreciate any help or hints.

Thanks, Iz

 

Gas quality?
Possibly in need of decarbonizing valves?

 

Still on the same tank of gas from the road trip, so considering fuel unlikely.

Carbon is a real possibility, although it would surprise me that it came on so suddenly.

Thanks Moocher, will do some more checking

 

Ever have any oil issues...know it new to you...just wondering if the turbo has gotten a bit of sludge into the oil line...and it has messed it up...if the turbo is no spooling....just thinking you are the first one to drive it aggressively in a long time...and you don't know what the prior owner used for oil...a nonapproved Dino oil can breakdown and slugs up pretty fast... you hop in...drive hard...mix it up...
More of a WAG...but many cars over the years have had oil issues,some (mostly low oil) with the turbo oil lines, usually leaking,but some with buildups....similar the valve adjustment system is oil psi dependant, and sludge deposits messes with the soloinoids.

 

Same line of thought I started with -- started with troubleshooting around the turbo as well.

Compressor spins easily with no play. Of anything, I would characterize it as having no boost, but not having a boost gauge isn't helping me answer that one. Tiny turbo, relative to the Cummins diesel I drive daily, which I couldn't hear before, so its not like I can hear it spool up anyway.

 

Short datalog from last night, just sitting in the driveway with a few revs on the throttle. Blue line, intake manifold absolute pressure -- min of 3 and max of 14.2. Do I need to subtract the barometric pressure, meaning the true MAP reading is about -11psi up to about 0psi (it has vacuum at idle, up to zero vacuum or boost when I stab the throttle)?

 

Hooked up the laptop for a datalog session on the road. Once the engine was up to temp, tried a WOT pull from stop, finally got the yellow half-engine light as I hit 2nd. Still feels like zero boost. Fuel rail pressure numbers look good. Not sure about the MAP absolute pressure readings. Checked the charge piping, clamps, and intercooler, with no blown joints.

I'm at a loss as to what's next to check.

 

Get a code from the check engine light? Current or pending?
Had a gen1 (SC) so not super familiar wity the turbo cars.

 

Just a loss of power light, no codes that I have been able to read.

 

AAAAaaaaand, it looks like I need a new turbo. Quick trip to Lowes for a PVC plug and a rig to verify the charge side plumbing -- no problems there. Pulled the top heat shield off, wastegate actuator and linkage working fine.

Fingers back in the cold side compressor wheel -- little bit of lateral play, and then finding out there is some vertical play. Enough that you can feel the wheel start to gain resistance. Ugh.

 

As I understand Mini boost, there is none until the engine is under a load of some sort --- you gotta be in gear and moving. I translate this to --- your MAP readings should be showing a vacuum, or negative PSI with respect to barometric pressure. Your chart shows MAP readings less than barometric pressure, so they should be accurate, just in units difficult to understand. Some guys report boost readings in bars, where 1 bar is sea level barometric pressure. Chances are, your own experience confirms idle RPM's have max intake manifold vacuum.

If you want to track MAP (boost) values , you should invest in a boost gauge --- one that you understand. Mine reads vacuum in inches of mercury and boost in PSI. I'm located at 4500 ft elevation, so with engine off but electronics on, the gauge indicates 5 inHg or about -3PSI. So, when figuring boost settings for my Manual Boost Controller, I add 3PSI to the gauge reading at max boost, or, zero boost starts at 5 inHg, and 20 PSI boost on the gauge is actually 23PSI from the turbo. My tuner confirms these calculations.

Sorry to hear about your turbo. This is one of the pricey failures. Plenty of options out there for replacements, just choose according to what you want to do with your Mini --- performance, track, daily driver, --- ? I don't recommend serious performance unless you want to spend a bundle on other complimentary improvements, and sacrifice reliability in the process. Lotsa guys upgrade to the JCW version and have "respectable" results.

 

Thanks, OBW, for confirmation on the MAP readings. No problem in changing the units. Just out of curiosity, where/how/through what sensor does the ECM measure barometric pressure?

As much as I really want to do a bunch of upgrades, reality dictates that I need to keep it close to stock.

Time to see if I can get this thing on my lift.

 

I have no clue how the ECM determines barometric pressure. Maybe the ambient temp sensor is dual purpose?

Using a JCW turbo is a pretty good option for replacement. Might need one new hose, for air inlet --- I've read that it's slightly larger in diameter. I've also read that it doesn't require a new tune --- just plug-n-play.

Have fun on your lift. Using the "service mode" makes turbo replacement lots easier.

 

A couple hours of disassembly, manifold and turbo are about to come out.

I'm guessing that the oil supply line banjo end at the turbo shouldn't be loose -- the end twists and pulls, assumed it should have been crimped. No oil came out of either the top or bottom oil line. I would have guessed that there was no anti-drainback valve or something functionally similar in the oil cooler block to keep oil up in the turbo. Or, I guess there could possibly just have been zero oil pumping up through the feed pipe at all.

Haven't put it in service mode. I may be fooling myself in thinking I can do this without, but I am pretty hard headed.

On a good (and bad) note, I did find my oil leak -- totally not where I expected. Looks like the shop the PO used for a couple repairs replaced the driver's side axle shaft and it is leaking at the trans.

 

Turbo / manifold assembly can be removed as a unit without going to service mode, just a lot more difficult --- a guaranteed knuckle-buster.

The OEM oil inlet hose is known to plug / foul and cause grief. Both ends should be tight, no twists or turns. Be sure to replace it when installing the next turbo.

Changing the axle shaft seal isn't easy either. It can be done without the special tools recommended by the Bentley manual, just a bit more messy.

 

Appreciate it OBW. About to order parts and hope they arrive by Friday so I can reassemble over the holiday.

 

Turbo out, waiting on parts. Man, I need to clean all the crap out of my garage...

 

Thank you ECS, box 'o parts to hopefully have me back on the road this weekend

 

Everything turbo-related back together. Of course, I decided I had to tackle the leaking left side trans output shaft seal while it was on the lift -- so much for that being a simple swap. Can't get the !@#$ thing out yet. About to hit the store and look for a couple different prybar tools to try and get the blasted thing out.

Fired the motor up for a few minutes to let the oil and coolant circulate -- not bad noises, just some oil burning off from the bit of mess I made filling the turbo with some oil.

What do I reset, or how do I get the half-engine light off the tach gauge?

 

My tranny was on the bench when the seals were replaced --- lots easier. If one is leaking, the other is probably ready to go. I suggest changing both. Without the "special tool" to pull it, you might try going in behind the seal (thru the seal opening on the other side) and push it out. A little hammering around the inner circumference with a long rod of some sort, should force it out. Just be sure you don't hammer on the wrong part. There's also wheel / gear pullers, small enough to get 2 - 3 prongs inside the seal, and capable of connecting to a slide-hammer. But that's getting close to the recommended special tool. Getting the new one in isn't easy either. I used a large socket, the same diameter as the seal, and my trusty hammer again. Crude, but no leaks!

We need to know the code causing your CEL. My guess would be coolant related --- not completely full. But, you had a lot of things apart, could be anything. CEL should reset itself when problem is fixed.

 

No code and no CEL -- just the half engine light. It will probably reset itself once it has a few clean runs, but I didn't know if it was standard practice to disconnect the battery for 15 min or so to clear it up.

Still working on the trans seal, trying a few new tools I picked up. The side that is leaking is the side that was already replaced (previous owner) by a sub-par quality shop.

 

Ugh, trans seal turned out to be a much bigger PITA than I originally expected. Which, I guess was to be expected... FYI to anyone out there, I ended up using a small Stanley nail puller as the seal removal tool and a 1-13/16 socket with an 8" extension as the driver to install the seal.

Thankfully, I peeked up under the back side of the motor as I noticed that I must have bumped off one of the vacuum lines to the canister as part of all my work (yes, it was on there before, and that wasn't my initial issue).

Just need to get it down on the ground, do some final fluid checks, and take a road test.

 

Update as I continue the saga...

So far:
* replaced turbo (play in the bearings) with new B/W OEM replacement (new DV and wastegate as part of the unit)
* tested pressure side tubing, holds 15psi with no leakdown
* installed new, temporary vacuum line from pressure controller (solenoid) to wastegate
* measured vacuum at wastegate and receiving enough to actuate the wastegate
* did a couple Seafoam treatments via PCV hose

Code p2885, half power indicator, and (still) no boost. Otherwise, runs and drives well.

Next up, replacing the full set of vacuum lines, vacuum solenoid, map/air temp sensor.

 

My experience with P2885 probably isn't applicable to you, as I have an oversized turbo. But, the only time I got that code was when I tried to accelerate too hard in too high a gear --- trying to pass without downshifting. Downshift to an RPM range where boost starts --- about 3500, then "punch it" --- no code. Normal driving around town --- no code. Also, WOT thru the gears --- no code. The ECU just didn't want to see 100% throttle without being able to get boost out of the turbo. Have you tried to isolate conditions when you get your cel? It helps having code reset capability "on the fly", as on AccessPort --- really handy tool.

BTW, my Manic tune eliminated my P2885 cel. Haven't seen it again.

When you say "--- (still) no boost", have you measured actual manifold pressure, or is this a "butt dyno" call?

Maybe disconnect wastegate linkage and verify it feels closed --- linkage might need adjusting.

Can you do a data log that captures data when you throw the code? Maybe include WGDC (Waste Gate Duty Cycle) in the data?

And finally, a SWAG --- have you checked the CAT? Previous owners may have caused un-healthy conditions that plugged it up.

 

No boost, in my own measurement, coming from 2 things -- MAP readings on the OBD2 datalog and the basic feel that it has about 125hp. Before, unless I was going all out, you could barely get your foot to the floor in first because of the acceleration. Certainly nowhere near the power it had before, in any gear. No turbo lag or power building as boost would build -- flat as the panoramic roof.

I have not checked the CAT -- good point.

New replacement and all I checked was that the wastegate would close under vacuum -- didn't do the full measurement as I have found directions to do so.