Is it normal? - United Bimmer Community

**zeaq328i** · 05-26-2005, 01:02 PM

Today driving the bimmer at 100KM/Hr at the highway.So i released the gas pedal without pressing the brake and when the speedo decreased to 80km/hr, i can feel a very very slight jerk.Is that Normal?.It's Auto.

I think it's changing gears?or whatsoever.

zeaq,

witeshark · 05-26-2005, 01:20 PM

Have a check of the transmission fluid, my first guess

**breden** · 05-26-2005, 01:36 PM

so do your rpms change? then it might be a downshift...u know what a downshift feels like right? this happens consistently from 100kph down to 80kph?

**zeaq328i** · 05-26-2005, 01:50 PM

Yeah, i think it was a downshift because the jerk can be felt at a very very very minimum.I didn't notice the RPM, but i think works fine.

**Rooz** · 05-26-2005, 03:55 PM

Quote:

Originally Posted by witeshark

Have a check of the transmission fluid, my first guess

lol, you can;t on our cars`

**komodo** · 05-26-2005, 05:00 PM

Quote:

Originally Posted by Rooz

lol, you can;t on our cars`

Huh? I know you can't do repairs on our transmissions, but I'd assume there would be a way to check and change the fluids...

**tomctx** · 05-26-2005, 11:50 PM

You can check the fluid on an auto. There is a fill plug. With the car level, the fluid should be at the top of the fill plug. They can also be repaired, just hard to find someone to do it. Most people want to change with rebuild unit. easier and more money for them.

**mpowerd** · 06-02-2005, 05:42 PM

check the fluid....dump it....and throw in some royal purple fluid....it'll make you so happy....i guarantee it!

**delmarco** · 06-02-2005, 07:05 PM

was it on a hill?
My car does that on hills whether going down or up....it does that!

I have a auto too!
Autos rule!!!!

**zeaq328i** · 06-03-2005, 04:49 AM

Quote:

Originally Posted by mpowerd

check the fluid....dump it....and throw in some royal purple fluid....it'll make you so happy....i guarantee it!

Not sure i can do it on a 328 cars

.Most probably is a downshifting.

Delmacro,
Yes.Only when going uphill or a slight slope.

**zeaq328i** · 06-07-2005, 10:20 AM

Just wondering,
You know when 0-20km,20-40km,40-60km.I can feel the gearbox is changing gears.Any of you experienced this??

**projal147** · 06-07-2005, 11:12 AM

Quote:

Originally Posted by zeaq328i

Just wondering,
You know when 0-20km,20-40km,40-60km.I can feel the gearbox is changing gears.Any of you experienced this??

yes. i have an auto also (wish it was manual though). when in drive you can hear/feel the car shift gears.

though i drive my car in manual mode (the button next to the shifter with an A or M) I use M and shift on my own. then you can really feel/hear the car shift and see the RPM's change.

Storamin · 06-07-2005, 11:17 AM

Quote:

Originally Posted by delmarco

I have a auto too!
Autos rule!!!!

Use some Royal Purple or Redline ATF if you decide to change the fluid.

**mullethunter3** · 06-13-2005, 12:09 PM

My 318is does the same thing. It's an auto and it has severe "engine braking" as I like to call it. I'll be going 95mph and let of the gas: it jerks but the tranny doesn't shift down or up and in a couple seconds I'll be doing 80mph. I don't think that anything's wrong with your car, it's just the quick switch between depressing the gas and letting it go that makes the car jerk a bit. It's nothing to worry about. Peace.

**bitcore** · 06-13-2005, 02:29 PM

Torque converter locking mechanism is disengaging or engaging, causing a slight jerk at cruising speeds when there is no gear change. If you catch the RPM's with your eyes when it happens, it slows down or speeds up about 200-400 rpm based on weather you are accelerating or decelerating.

Mine's a little weird, it usually happens when I was holding the throttle down to maintain a highway speed and let go to slow down a few MPH and I press it back down a bit, mine can get confused and disengage and re-engage itself almost immediately 3 times in a row, making it seem like my gears are stripped to hell. (I know they aren’t, I can't cause them to jerk under acceleration or downshift induced deceleration) This normally happens after I've been driving for at least 50 miles and the torque converter and gear fluids have warmed up significantly. IE: much more in the summer.

If the RPM's change a significant amount, it's a gear shift. Otherwise it's the locking mechanism... Or a tooth on one of your gears is missing, it just slipped and your screwed out of at least $2,000 :P

Without the locking mechanism, our cars would have drastically crappier gas mileage on the highways since when it is disengaged, the only connection the engine has to the rear wheels is though the viscus fluid in the turbines, this is why automatic tranny's suck.

Normal operation and I wouldn't worry about it unless it STARTS getting worse. If it starts getting noticeable worse, then there IS a problem. If you want to have a level of security without disassembling the gearbox, change the fluids and examine the sump magnet and filter for metal shavings. That's all you can do without blowing at least $500 on a mechanic to drop the transmission and crack it open to take a look, and if you do that, there's a 50-50 chance that it will never run the same again.