6th gear shudder with ac on

[m3dragon]

I searched around and this was the closest I could find to the issue
http://www.1addicts.com/forums/showt...dders+6th+gear

Anyone have any issues when in 6th gear, ac on and hard acceleration from 70-80/83 get a shudder? There is not rattles or metallic sounds, just a shudder.

Happened 4 times this weekend which was new. Only happened when the AC was on from what I could tell when I tried it a few times. I kind of remember having the same issue in my e90.

Theory is AC is freaking out and causing the shutter. Thoughts or is my logic sound?

[bmw1racer]

6th gear is overdrive... Accelerating in that gear would be hard on the engine, I'd think.

You should drop down a gear or two, huh?

[m3dragon]

I am not trying to fly past someone. So leaving it in 6th the car has enough pull to pass people. just odd it happens now after 11k on the car. Just seeing if it is a 1M thing

[andrews]

I *believe* I am seeing the same issue. I can't say I have tried this with the AC off. It almost feels like the clutch slipping, but I don't think it's that.

[m3dragon]

I was thinking clutch but 11K on my car at least it should still be good. I can't isolate it but it is just odd. Almost like something is slipping or?

[andrews]

I have just under 11k on my car too and I have had this happen waaay before that too.

[Dackelone]

Could be your clutch. Some cars have had leaking/bad rear crankshaft seal. That would leak oil onto your clutch.

But I think it might be more of an ignition miss. When our cars misfire the whole car shakes. Almost like your driving on square tires instead of round ones. IF its a mild misfire.. it would be subtle.

Either way I would have it checked out. Have your dealer check for any shadow codes - those won't show up on your key fob... have them read the car's dme memory. Only "hard" codes are stored on the key fob.

[Simsims]

Originally Posted by bmw1racer

6th gear is overdrive... Accelerating in that gear would be hard on the engine, I'd think.

You should drop down a gear or two, huh?

you'd be surprised how much power the N54 can output

2000+rpm 6th gear floor it and it's still pleinty fast.

[m3dragon]

Yeah I was going to go to the dealer to ask them to check it out. Sounds like I am not the only one then.

The paranoid side of me was saying miss fire because of the fuel pump. I will let you all know what I find out

[Dan Parker]

Next time it does it shut the a/c off immediately. Warranty time but it might help troubleshoot the problem.

[bmw1racer]

Originally Posted by Simsims

you'd be surprised how much power the N54 can output

2000+rpm 6th gear floor it and it's still pleinty fast.

But not as fast as dropping it down a gear.

[m3dragon]

Originally Posted by m3alabama

You are not mixing e85 are you?

HAHA no, this is CA, we get crap gas. 91 octane oh yeah...

I will check the air filter as I do run scoops so it gets dirty faster.

I plan on stopping by the dealer so stay tuned.

[T1T2GRE]

No issues here. The car does take off though

[Simsims]

Originally Posted by bmw1racer

But not as fast as dropping it down a gear.

1M does 70-90 in just a few sec in 6th gear

5th would just cause more trouble.

[m3dragon]

Originally Posted by T1T2GRE

No issues here. The car does take off though

Yeah that is no help trying to find others that seem to have the same issue.

[trinity_2200]

I think a similar issue happened to me today, When I was overtaking some one in 5th gear, WOT, after about 2 - 3 seconds, suddenly felt some vibration and a bit lost of power, I release the throttle immediately. . .

[RimasRS]

Sometimes i feel same thing on my car. I thought that could be plugs.

[Dackelone]

I drive WOT in 6th all the time from 80 kph to 290 kph(!) Autobahn driving - and I never feel any shuddering.

IF your feeling some surging I would try a different brand or premium fuel and retest. It could also be carbon buildup too. But I think the thing that makes the most sense is a slipping clutch. Have you looked under the car for any oil leaks? Pull off the tray under the trans and have a look. IF the rear crankshaft seal is leaking you might not see any oil on the ground. G.L.

[RimasRS]

Originally Posted by Dackelone

I drive WOT in 6th all the time from 80 kph to 290 kph(!) Autobahn driving - and I never feel any shuddering.

IF your feeling some surging I would try a different brand or premium fuel and retest. It could also be carbon buildup too. But I think the thing that makes the most sense is a slipping clutch. Have you looked under the car for any oil leaks? Pull off the tray under the trans and have a look. IF the rear crankshaft seal is leaking you might not see any oil on the ground. G.L.

One thing which makes me think that is not clutch because RPM would jump up.
Although I saw on my car a little little oil on front of my gearbox.
I think I will try to replace my plugs if this will not help I guess then will have to deal with seal. Wondering what work is involved to replace that seal?

[Dackelone]

Originally Posted by RimasRS

One thing which makes me think that is not clutch because RPM would jump up.
Although I saw on my car a little little oil on front of my gearbox.
I think I will try to replace my plugs if this will not help I guess then will have to deal with seal. Wondering what work is involved to replace that seal?

Your gonna have to R&R the trans and driveshaft, then remove the clutch and flywheel. Then you will see that rear main (engine) seal. Its a lot of work. I would go ahead and replace your clutch(press plate, disc, throwout bearing and resurface your flywheel) while you are in there.

G.L.
Dack

[Piets94]

Not sure if I have exactly the same issue BUT it sounds similar. I have experienced what feels like the boost cutting out under WOT in higher gears (5, 6) from 80+ kph, say when passing. It's a distinct jolt at about 2.5k revs that instinctively makes you get off the throttle. Can't say if I've noticed that the ac affects it as I drove with ac off most of the time.
I thought knock sensors or plugs, but dealer has shown no codes on 2 occasions now. Not sure if that helps, but I just pass in 4 th now, quicker no doubt

[RimasRS]

Originally Posted by Piets94

Not sure if I have exactly the same issue BUT it sounds similar. I have experienced what feels like the boost cutting out under WOT in higher gears (5, 6) from 80+ kph, say when passing. It's a distinct jolt at about 2.5k revs that instinctively makes you get off the throttle. Can't say if I've noticed that the ac affects it as I drove with ac off most of the time.
I thought knock sensors or plugs, but dealer has shown no codes on 2 occasions now. Not sure if that helps, but I just pass in 4 th now, quicker no doubt

Do you have a tune?
And once again your solution was o go in to lower gear thats it?