First post about my 4.8is (long)

marcjac · #1 12-27-2009, 07:30 AM

First, let me say how INVALUABLE this site has been! I have learned a LOT and plan to upgrade to Premier membership very soon. After a long search to replace my Grand Cherokee Overland 4.7HO, my wife & I decided on an X5. We'd test driven a bazillion different vehicles, but were smitten by an '06 X5 4.4i. Since I'm a "more power" kind of guy, I figured if 4.4 was good, 4.8 would be better!

Through Carmax we found an '05 4.8is with 59k in Arlington, TX and paid to have it shipped home to NC. It's gorgeous! (looks like all the other Lemans Blue ones with pictures on this site). However, I'm underwhelmed with the performance and the sound system (premium). If the original owner is on this site, any info would be very helpful.

It runs well, no misses, starts right up, etc. But my gut is telling me it's slower than the 4.4 and slower than my Jeep. It's throwing no codes, but it does seem to hesitate when I step on the gas (have to push down an inch or 2 to get rolling), and while it'll run right up to redline, I don't get the g-forces I was expecting from the 355HP engine. Would any diagnostics show any parts not running up to spec (I'm wondering about MAF and maybe the cam sensors from what I've read online). I hate to just throw money at it, but I have to say at this point I'm a bit disappointed with the acceleration after just 1 week of ownership. And the expensive Supersprint exhaust that's on the X5.... way too quiet! X-pipe soon to replace resonator!

The sound system... I keep tweaking the DSP settings and it's getting better. I'm going to add the aux line in and see how it sounds with my Blackberry and then XM. All the speakers are operational with no crackles or cutouts. But again, I expected more. My wife's '05 FX35 sounds far superior. Any way to confirm the sub is working properly?

Thanks all for your input! Sorry for the long post; I do tend to be long-winded lol.

Marc

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askhao · #2 12-27-2009, 11:05 AM

that's unusual of a 4.8is to feel slower than a 4.4...
i guess you could dyno it to see how much hp/tq it's pushing out.

BMWLOVER · #3 12-27-2009, 05:58 PM

Congrats and welcome to Xoutpost!

You could go test drive another 4.8is at a dealer near by to see if there is a difference.

A lot of people complain about the sound system not being good and have done upgrades which you could easily find by doing a search.

Quicksilver · #4 12-27-2009, 06:28 PM

RE: the sound system. depending on your system, It actually reproduces what you put in.
If you feed it a bad recording that's exactly what it will sound like.
The system is more flat than colored from an equalization perspective

It's too bad but 90% of what is recorded in studios is garbage.
Great beat yada yada bad engineering.

I have an E-53. The treble at 100% Bass at 50%
But the kicker is playing a recording like
101 Eastbound by Fourplay on the CD player.
No not an iPod or other phones.

The results are a total WOW. Why?
The CD is recorded 24bit digital by
fantastic engineers.

marcjac · #5 12-27-2009, 08:07 PM

Thanks, all! I agree with Quicksilver's comments pertaining to "GIGO" (garbage in/garbage out). I continue to tweak the sound system, but have yet to play a CD. I'd used XM for the last few years on my other vehicles and miss the variety of options it offers. Trying to listen to local FM is like taking a giant leap back in time. But that'll soon be remedied:-) I burned a few CD's tonight, so we'll see how they sound tomorrow.

As for the (lack of) performance of the 4.8, I may in fact seek out another one (or even a 4.4i or 4.6is) if I can find one locally just to compare. I'll keep you posted as time permits. Thanks again!

Marc

reyxlp · #6 12-27-2009, 10:12 PM

Marc,

I am very new to the X5 myself, having also very recently picked up a 4.8is, but I believe - like many BMWs - the car is just about due for the Inspection II service (60k miles).

Unless you planned on doing it yourself, when you find the shop where you will be servicing the car, have them do the Inspection II and see what they find in terms of the "underperformance" you feel you are experiencing.

If you are having trouble finding a good local independent mechanic, I've always relied on www.bimrs.org and have had great results.

Also, with proof of ownership, sometimes your local BMW dealership's service department (if they aren't too busy and especially if they are trying to earn your future business as a new owner) will print out the service history of the vehicle for you, if it is available.

You can also run a Carfax to see which dealership(s) serviced it during the warranty period and contact them directly for service history.

Good luck and report your findings.

Rey

Mujahid · #7 12-28-2009, 08:21 AM

Quote:

Originally Posted by marcjac

First, let me say how INVALUABLE this site has been! I have learned a LOT and plan to upgrade to Premier membership very soon. After a long search to replace my Grand Cherokee Overland 4.7HO, my wife & I decided on an X5. We'd test driven a bazillion different vehicles, but were smitten by an '06 X5 4.4i. Since I'm a "more power" kind of guy, I figured if 4.4 was good, 4.8 would be better!

Through Carmax we found an '05 4.8is with 59k in Arlington, TX and paid to have it shipped home to NC. It's gorgeous! (looks like all the other Lemans Blue ones with pictures on this site). However, I'm underwhelmed with the performance and the sound system (premium). If the original owner is on this site, any info would be very helpful.

It runs well, no misses, starts right up, etc. But my gut is telling me it's slower than the 4.4 and slower than my Jeep. It's throwing no codes, but it does seem to hesitate when I step on the gas (have to push down an inch or 2 to get rolling), and while it'll run right up to redline, I don't get the g-forces I was expecting from the 355HP engine. Would any diagnostics show any parts not running up to spec (I'm wondering about MAF and maybe the cam sensors from what I've read online). I hate to just throw money at it, but I have to say at this point I'm a bit disappointed with the acceleration after just 1 week of ownership. And the expensive Supersprint exhaust that's on the X5.... way too quiet! X-pipe soon to replace resonator!

The sound system... I keep tweaking the DSP settings and it's getting better. I'm going to add the aux line in and see how it sounds with my Blackberry and then XM. All the speakers are operational with no crackles or cutouts. But again, I expected more. My wife's '05 FX35 sounds far superior. Any way to confirm the sub is working properly?

Thanks all for your input! Sorry for the long post; I do tend to be long-winded lol.

Marc

Hi there, I also had my vehicle delivered to me and also experienced a bit of "under-performance". Got the BMW technician to reset the adaptation. It could be that the car has adapted to lower/higher altitude settings etc. I also did not have any codes.
Hope this helps.

Weasel · #8 12-28-2009, 09:04 AM

I agree with the adaptations comment above. Not only does the local climate/altitude etc. make a difference, but odds are the last owner was driving very soft footed towards the end of ownership and the adaptations are set as such. A quick engine and transmission programming with newer software will make it feel like a whole new truck. (and yes, I know from exprience

)

Mujahid · #9 12-28-2009, 09:47 AM

Quote:

Originally Posted by Weasel

I agree with the adaptations comment above. Not only does the local climate/altitude etc. make a difference, but odds are the last owner was driving very soft footed towards the end of ownership and the adaptations are set as such. A quick engine and transmission programming with newer software will make it feel like a whole new truck. (and yes, I know from exprience

)

Hi Weasel, please can you share a little more on the "programming with newer software". Are you talking about flash-tuning? that is replacing the entire map. Or is it just newer Dealer equipment that "tweaks" the settings. Would this be a step further than just adaptation setting?

marcjac · #10 12-28-2009, 11:07 AM

Excellent suggestions; I didn't realize my X5 was due for the Inspection II service at 60k. According to bimers.org, that would include new spark plugs and a host of diagnostics. It would be an excellent time to get the software reset and/or updated. I have tried the tranny reset procedure, which seemed to make the shifts a bit more snappy. Based on the above suggestions, I'm sure I can reclaim the lost power I feel is MIA.

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