4.8 owners notice this?

[rgnbull1227]

There was another thread about a revving 4.6 where the torque converter could be slipping. I noticed from the very beginning that as I accelerate in manual mode while in a gear (lets say 3rd) the revs will jump as if it just downshifted but it is actually in the same gear. I was told that this is a result of the new engine and it was the valves adjusting. Does anyone also have this experience? IS it the valves or is my torque converting slipping?

[vinuneuro]

failing torque converter or slipping tranny would do that. btw, what happend with the paint issue?

[LeMansX5]

I have not noticed it but will test it out and let know.

[DINANM3]

The same exact thing happens to my 4.4 I thought it was the tourque converter slipping and went to the dealer but they told me that it is the valvetronic adjusing the valves.

What is the real reason for this. Is the dealer lying to me.


Let me know what you find out please.
Thanks

[cimbro]

I think that it is the torque converter slipping. yes, because it's unlocked under the speed of around 60MPH so if you accelerate also in manual mode es. 3th gear, it slipp till the engine decide to stop it. i really hate this!

[ktulu]

I've noticed mine slipping but it seems to only do it when I change into or out of Manual while sitting still. Then when I take off it feels like a clutch slipping. Figured it was normal but maybe I should pay more attention to it. I have still yet to get used to the power this beast has. At times it seems to really be full of it and other times it seems just so so. Though when I nail it to the floor there is no doubt that BMW has done an excellent job. That being said there is always room for improvement. I am hoping that the rumors I read about the new V-10 going into the next X5 are true...THAT would be sweet!

[rgnbull1227]

Originally Posted by vinuneuro

failing torque converter or slipping tranny would do that. btw, what happend with the paint issue?

I am meeting with the BMW rep tomorrow. Will keep everyone posted. So it seems have of you say its the torque converter and half says it the valves adjusting. I would really like to know which it is. MAybe Steved knows. I will edit the Topic and request that we get his input here as well.

[Steved]

I've not experienced this in any of the cars I've driven (and I've driven 8 different cars now). The 4.8is engine in the X5 is brilliant and I've never experienced anything less than exceptional behaviour (except when I had a dud ECU). Sounds like a transmission problem to me, are you having any unusually hot temperatures over in Miami?

[Steved]

OK, I've tested this out on my car now. Obviously every automatic gearbox allows a little bit of slippage via the torque converter. (There's a good explanation about 'slippage' in the following article http://www.bankspower.com/Tech_under...rqueconver.cfm.

When I slot my car in 'manual 3rd' and plant my foot down the revs rise by around 500 to 750rpm whilst the car accelerates forwards and then the revs build upwards from there. It's not like a manual transmission where the engine revs and transmission accelerate precisely together, but it's nearly as good. It does this in 1st, 2nd, 3rd and 4th gears then only at low revs in 5th gear (around 2500rpm or less) and it never does it in 6th gear. It's nothing like changing down a gear and is 'clearly' the slippage of the torque convertor as the fluid inside is compressed and finally locks the impellor and turbine together.

It really has nothing to do with the valvetrain as the engine does not change at all, it's just the transmission allowinga bit of give before engaging solidly.

What kind of revs does yours rise by to cause you to be concerned?

[DINANM3]

So is this slipping normal or is something wrong