My R50 has an oscillation/shake when accelerating between 2000 and 3000 rpm. I call the feeling axle tramp, but I don’t if that’s a common term. Its a pretty low frequency shake that you can feel through the front wheels and I can tell the engine is moving around. Everything smooths out above 3000rpm. More throttle produces a more pronounced shake. There is no shake when not accelerating.

I replaced the lower engine pitch mount and the upper pitch mount as well since I though it was just the engine shaking, but that didn’t solve it. I also replaced the LCABs with street rated poly and that didnt help either. Alignment is good. I have some fuel injector cleaner in the tank now as A co-worker recommended I try that since he though it could be a fuel delivery issue. This hasn’t helped yet, but I only got through 1/3rd of the tank before my PS pump went haywire.

Any ideas?

 

Anyone have any ideas as to what this might be?

 

is the shake related to engine speed or wheel speed?

 

The shake is related to engine speed. It will happen at any speed and in any gear.

 

at that RPM I would be worried, knock there is really bad. Start with plugs, if no change do a leakdown and compression test

 

I advice you to check your air filter.Do a drive test without air filter and see if there is a change in engine operation.

 

Any codes or cel?

 

Air filter is super clean. Shouldn’t be any issues there. The filter housing tabs are broken on one side though.

No codes, and no CEL.
The only other issue with the way it runs is that the idle speed fluctuates a bit: 830-770rpm. It wobbles up and down through that range once the engine is warm (cold engine high idle is steady at ~1000rpm).

 

Short version:
I had similar symptoms a few months a ago. Trying to solve other issues; I did a simple maintenance; New NGK plugs, NGK wires, TMAP & MAP sensors & Fuel filter.
Believe it or not - it solved all my issues.

Long version:
I wasn't going to submit a reply. I'm not as seasoned as most of the contributors here.
I know/experienced the exact same symptoms you described with my '04 R53. Although it didn't idle rough or fluctuate. I did have other issues with surging and a jerking effect at acceleration. Low & High rpms.
Like you described, I could feel a slight rough lag or "grumble" at 2.5k -3.5k rpm while accelerating/shifting. I fluttered the gas pedal until the car felt like it was up in line with the speed/revs. I feared at first, I had dropped a cylinder. Or the CV and/or the clutch was going bad. Luckily, All symptoms were resolved from the fix I outlined above. Sometimes It's hard to tell if the Mini is even running at idle. It idles/runs that smooth. The acceleration is instant. No more lags or "grumbles" while driving. I tend to feel it was starving for fuel. I admit, though - I am no expert on a MIni.

 

​​​​​I'm leaning here as well, with one quick question...
​​​​"Does it seem to change under different loads or acceleration characteristics like full or partial throttle?"

As far as the above, if you consider known issues when it comes to parts wearing out for the Mini, I'd try things in this order:
-Plugs
-T-MAP (MAP usually lasts a lot longer not being subjected to as much heat as the T-Map)
-Wires (esp aftermarket, OEM seem to last really well)
-Coil, (again, esp aftermarket, may also just be simple corrosion on a contact, #3 tends to do that more than others for some reason)

Good Luck

 

The problem gets worse as you add more throttle. At full throttle the roughness is maximized. It is a linear- the amount of roughness increases steadily with the amount of throttle.

I checked the plugs and connections at the coil pack a week after I bought the car. I added some dielectric grease to the connections and the plugs looked good. Adding the dielectric grease made no difference.

I'll order up some plugs, new coilpack + wires and MAP stuff and see what happens. Fingers crossed! I'll close up the airbox fully too. The broken clips allow for a bit of unfiltered air to enter the system. So, I'll get another box with no broken clips or scrape together something to add a bolt or two to the side that is supposed to be held shut with clips.

 

Hmm... Could it be that your Harmonic / Crank Damper is loose, cracked, "on it's way out" ? = Shaking / vibration.
If the tune up doesn't help; I might suggest a compression test just to rule it out.

Very interested in what / and hope you can figure it out.

 

The whole between 2-3k RPM is making it tougher to diagnose.

If it were through the whole range I'd be leaning to possible fuel filter, but in just that range, that shouldn't be the case and makes a spark issues still more likely.

Let us know.

​​​​​​​Oh, also check the connections, including vacuum, to the MAP sensor, the T-Map will have a tendency to effect idle and be more noticeable when they go bad, but this MAP won't be near as drastic of a change when not working properly.

 

I have the same issue with had been bothering me for quite a while. Feels like stutter feom around 2800 to 3600 rpm . Feel.it more in lower gears .
Has definitely got more noticeable as I added my mods. Air intake, cam , etc.
I tried reverting back to stock coil pack, wires, plugs , even stock intercooler and it still did it . Also had fuel filter done about a year ago .
the only thing that seemed to help somewhat this issue in my case was when I replaced my tmap sensor on the throttle body. It's still there but to a lesser degree. My car is running high negative stft and I have noticed via obd2 dongle it is pulling lots of fuel at those rpms, hence perhaps causing the weird feeling of hesitation or jerkiness .

 

I installed the new plugs, plug wires, and coil pack last night. Took it for a spin around the block and the engine is maaaaybe a bit smoother. I'll find out more when I drive across town tonight.

My Mini has mostly been out of commission for some time (dead PS pump), so when I wrote this initial post I hadn't driven the car in a few weeks. Upon further driving (I put a manual steering conversion in to make the car temporarily drivable), I have seen that this phenomenon is really by far most present in second gear. It is juuust noticeable in third, but in first, fourth and fifth I can't detect the rough feeling.

I'll clean out my MAP sensor tomorrow. After that I'll seal up my airbox and then start to try to troubleshoot the possible vacuum leak that is giving me the rough idle.

 

Sounds like my driver side CV Shaft before it exploded this Sunday. It was a brand new shaft. My son killed the previous driver side shaft 2 weeks agao so I wasn't driving when it let go. Replaced that shaft, drove it around the block then threw my son the keys. I didn't test it like I should have. I didn't even go over 25. Last year the passenger side made a bad oscillation/shake before I replaced it. Only in low RPM when acclerating/decelerating.

Back to this weekend, I was heading to autocross on Sunday and felt a slight oscillaiton/shake when accelerating in low RPM in 3rd gear, and yes...it smooths back out as you get higher in the rev band. I didn't like it, but it wasn't bad. Nothing like 5th or 6th gear with my passenger side shaft before I replaced it. That was a pretty obvious shake/oscillation. This was more subdued. But definitely noticable.

I launched it on my first run and spun up the tires to get some heat in them. Only made it about 30 feet. Inner joint blew apart. No clicking, no boot tear, no grease prior. Replaced it last night and the oscillation/shake is gone completely now. Smooth as butter.

 

Update: I've installed the new plugs, new coil pack, new plug wires, cleaned the MAP sensor and sealed up my airbox. No real difference. A bit smoother though, so I'm not displeased, but I'd guess that the issue does not lie within the engine. Maybe going to the hydraulic right ride engine mount would clear it up? I dunno. I'll probably just leave it for now. It's not so bad now.