85k miles.

I'm having an issue where there is a bump or thud when quickly changing from 0 to 10% throttle.

It's pretty bad in 2nd gear. Another example is going 3000 RPM in 3rd gear and quickly changing from 0 to 10% throttle. The bump / thud is strong enough to cause the dashboard to make a small noise as well. You can do it rapidly and the bump / thud will happen every time.

What could be the issue?

Reading a similar post, it might be control arm bushings?

 

lock the steering wheel, jack up the each front, one at a time, and grab the tire at 9 and 3 and try to move the tire right and left if it moves at all, take a flash light and check the bushings at 85K it's about the right time for them to start going bad.

 

I'd look at the engine mounts .... sounds like you have movement of the entire block.

Maybe consider an engine stabilizer bar
http://www.mossmini.com/Shop/ViewPro...eIndexID=72276

I get this kind of sounds out of my 79


hmmmm....grabbing the wheel at 3 and 9 is a test for a bad wheel bearing isn't it? I found the control arm bushing to be more related to suspension movement and not simple accelaration loads and replaced to poly at about 50k on an 02-S. (bad control arm bushing also allowed some side sway in the front end....) Wheel bearing noise typically increases during turns and has nothing to do with acceleration load IME.

If the engine mounts are good I might be looking CV's . . .

But I'm a hack so don't trust me .

 

Well I'll be the 1st to say BJ is anything but a hack. He's given many NAM members great help over the years.

I like to check the wheel bearings with hands on tire at 12 and 6 and bushings at 9 and 3 unless I can get under the car with a pry bar and check with that way too. Was just trying save the guy a trip to the shop.

If it is a bad mount you'll want to replace the whole mount upper that leaks with the TSW motor mount the damper or brace won't help a bad mount. Also check the lower motor mount we have found them bad on high mile cars with bad upper mounts too.

As BJ's knows it's hard to diagnose issues on-line.

 

Amen as to diag' by this path ....

and I would not ADD anything b4

I was sure the original was good enuf 2 work

 

It turned out to be bad control arm bushings AND a bad upper engine mount.

I'm going to replace the bushings with powerflex bushings but I'm trying to determine if it's worth the extra money and if there's additional labor to do the ball joints at the same time.

The bushings are $95 but there is a kit for $299 that has:
1 set front powerflex control arm bushings
2 outer ball joints
1 Left inner ball joint
1 Right inner ball joint

 

U sure there isn't a dead body under the hood?

 

FYI, since the original post,
I have replaced the upper stabilizer and lower engine mount with OEM mounts and replaced the upper engine mount with a urethane one from TSW. The engine movement went away, but the bump is still there.

Quickly taking my foot off the throttle quickly any time I'm accelerating in 3rd will cause a single bump every time.

I guess it has to be the control arms... Waiting on the time and money to get that project started.

 

Could be the axles?

I'm having a similar problem and it's really annoying/scary sounding.

I can replicate the sound somewhat by leaving the car in gear, jacking it up, and then rotating the tire back and forth. There is a lot of play and the sound happens every time I hit resistance.

I also need strut mounts (rubber's all cracked), need to fix my mushroomed shock towers, need all new motor mounts and probably a tranny mount, and most likely need CA bushings.

Lots of work to do, lots of money to spend. Yay Mini ownership. Why did I buy this at 76k again?

 

Control arm bushings generally make that thumping noise you describe. But its usually the other way around where it makes noise when you brake abruptly. At about 5mph or so try jabbing the brake, you should feel your steering wheel jerk and maybe hear a thud. You can also have someone outside look at your front wheels while you're doing this, and they should be able to see the front wheels jerk and lurch forward.

 

There ought to be a sticky somewhere that informs people that at 80K miles, these are the things that need to be replaced... Motor mounts, CA bushings, upper strut mounts and usually install strut braces... Same thing on mine and from reading other threads it seems to be the TBO on these items...

I went with the powerflex bushings and love the tight feel they give the car under load...

 

wow, I'm having the same sympthoms from my right front side. I was initially thinking it can be the CV Joint but now am unsure after reading all of the posts above.
I do have bad upper engine mount that has gone bad again about 6 months ago.
The problem is that the sound is new, only few days old. It happens upon taking of in 1st, and also during pressing the gas and letting off the gas in pretty much any gear although it's most audible in 2nd and 3rd at lower speeds.
It's basically a loud "tick" when pressing and "tick" when letting off.
I will have more time on Saturday changing oil on wife's car so maybe I'll jack up the MINI and have wife "drive" it while on the stands and see if I can look for the true cause.
Can it really be CV Joint so early (only 57k miles)? I've had couple other FWD cars before and kept them for 90k miles or longer but this has never happened to me yet.

 

Yes, it could be the CV's. I replaced my lower motor mount, and control arm bushing over the summer and I have the noise you are all describing with the exact same symptoms. There are are a couple places where I know there is additional play however:

-Flywheel: Should have replaced it when I did my clutch, but the plate had a lot of life left. In any event mine had just under a 1/4in of rotational play in it just by pushing it with my hand... may have gotten much worse in a hurry. Guess the transmission comes out over the summer and the Valeo I have sitting around goes in...

-Outer ball joints: Found out these were bad when I did the clutch. Didnt have time to replace them so I will do them in 2 weeks

-CV's: 36k miles on the car, and a lot of really hard driving an AutoXing. If the fact that the rubber in both the lower motor mount and the control bushings had worn out in that time, I'm wagering the CV's are pretty beat as well (given that they see a LOT of loading).

I get a sound like a golfball rolling around in my glovebox. I had the exact same sound when I blew my passenger motor mount. The thing is that there is no sign of leakage from it...

 

well, the info in this thread does not comfort me :-(
I don't really have a budget to start replacing 5 possible things one by one to find out which one it really is.
Hopefully I'll be able to pinpoint some more specific area over the weekend.

 

Just realized the flywheel is a big possibility. I've got a lot of chewbacca-ing going on as well, and the clutch is finally starting to feel like it's on its way out... Going with the Valeo kit.

Not including labor I've got like $1,500 in parts to buy.

 

The chewbaccaing isnt related to what is being discussed int this thread. Yes, it is a problem with the flywheel, but what we are looking at hear would be the springs and bushings within the flywheel going out, that doesnt have a definitive sounds. Chewbaccaing is usually indicative of a glazed flywheel, which is really just an annoyance.

I hear you rally, diagnosing the problem kinda sucks. I'll replace my ball joints in the next month (WINTER BREAK!!!) and see if that helps at all. It only got really bad in the last 3 months, and I know my ball joints were on the way out. Of course if the amount of play I am getting I am getting now was just the joints then a wheel is going to fly off any second. haha

 

So i tried to look for the cause on Saturday and with the front on the jack stands and car running in various gears I was unable to reproduce the noise. I'm guessing that this is the lack of real load on the engine/axles/whatever.

however, having the car running and being able to listen to the noises under the hood, there is a strange noise from the transmission when car is idling in any gear (meaning no gas but the wheels are spinning). It's also a crackling sound but from the transmission itself, and it's a different type of sound from the one that I was initally trying to diagnose. Also the transmission is in front of the driver and the original noise was definitely coming from the passenger side/wheel area. The sound is similar to the one that transmission emmits if the car is not running and you jack up the front and roll the wheel back and forth. I think it's the slack between the gears that i'm hearing but i've never experienced this since it's hard to hear this while the car is running down the street. Maybe it's normal, maybe not.

Also, when the car is running in gear on the stands (especially in 4th and 5th) i get strong vibrations on the steering colum and the car overall past 3k RPMs.

 

I'm hearing the same thing rallymaniac, and it's referred to on here as flywheel chatter I believe. I just don't know how much gear slack there should be, and how much of that could be due to worn out springs in the dual mass flywheel? All I know is that it feels like this is what is happening whenever I tap or let off the throttle, and it's pretty disconcerting. Sounds like a hammer hitting the bell of the gearbox occasionally.

 

That is normal. I keep forgetting to but one of these days I will post a video of a motorcycle engine with a dogbox idling in first on my engine dyno. THAT is some real chatter.

When you did this experiment did you turn traction control off? The car will freak out if you dont.

 

actually i didn't turn the traction controll off. It was just on the stands rolling. I did get the ABS light and TSC light once car was off the stands but it cleared as soon as i drove out of garage.

So the gear slack is normal per your post. So now the big question, what the hell is the other noise (the original one)??? We know that no load on the engine doesn't reproduce it. I'm leaning towards my bad engine mount. I don't know how exactly that damn thing is constructed but if there is any slack inside it's possible that when the engine shifts the inside of the mount hits the housing and that's what makes the noise.

 

Generally, if someone can look at the engine while you put it in 1st and/or reverse, the mount issue can be seen. I remember some cars you could dent the hood with the engine. I'm not sure about the mini specifically, but it is worth a quick look.

 

Have you checked your lower motor mount? The big end is just a rubber skeleton and mine was pretty killed at 35k miles. I'm starting to wonder if my trans mount is bad too. In my particular case the only want I will no for sure is to go in and replace the flywheel, until the slack I know I have there gets taken out I will just be chasing my tail. That is why I am not about to run off and replace my axles.

 

I'll check it after holidays. If anything, I'll be buying a replacement mount for $200

 

The lower motor mount is cheap, about $45 off of pelican parts! If that is bad changing it will make a huge difference.

 

Sorry for the double post but,

I went and checked my CV today. I did so by rotating and observing if the inner CV housing moved the same amount the hub did. It did in fact do that, so I know my CV are at least not completely shot. I did notice a LOT of play in my transmission, but with the TORSEN diff I cant say how much is normal.

I did notice that the nut holding my passenger side motor mount to the engine bracket was quite loose, tightened that and it helped a little.

Outer ball Joints in the next week or two, and will write back if that helps at all.