I have the worst luck!
 

So recently I bought an 05 4.8is a couple of months ago to replace my e39 M5 since my boys are growing and working from home the only driving I do is hauling kids around. I have always loved the look of the is versions and was hoping it would still feel sporty enough so I wouldn't miss the M5 as much. Anyways I found one on craigslist, it only had 80k miles on it and the owner had an extended warranty on it and had recently had a valve job done performed at BMW of Nashville. Also had new rear tires and one of the front air shocks replaced. Plus it was imola on alcantara which is sort of rare. Whoever had it before must have been into modding (the guy I bought it from was in his 50's and wasn't into that), which most of it was distasteful in my eyes, chrome surrounds around the lights, ebay door lock pins, and metal light up door sills. But I looked past that and was hoping it would be reliable which was my biggest fear after spending some time on these forums before and knowing some expensive items that can go wrong. And that is coming from someone who has owned 4 M cars in a row (I had 3 different e46 M3's before the M5).

So based on my research here, these items were the most common and were usually quite expensive. And here is what I have experienced in the last 2 months of ownership.

-Leaky Valves: Thankfully that was taking care of before I bought it and I hope it will not be an issue in the future.

-Panoramic Sunroof: I had the sunroof on tilt one day and the second portion got stuck and prevented it from operating. I removed the two screws to disable the 2nd portion and so far it is working now. But I still get a loud popping noise when I open it so I am worried something else might break.

-Air Suspension: I noticed that the rear passenger side sit lower than the driver's rear and it appeared to be losing a little air overnight. So as cheap as rear bags are I decided to replace them. It still sat lower on the passenger side after I replaced them, but I had just received the Romania software from eBay and tried to even it out via INPA. At first I started adjusting the wrong side by accident, and then when I tried to pump up the passenger side somehow I got it stuck up too high. I had to let air out of the lines for it to move again. I then switched to DIS which I thought is easier to use and I got the ride height evened out and then lowered it at the same time. HOWEVER, it is still leaking on passenger rear where I can barely stick my finger between the fender and tire if I let it sit for more than 24 hours. So either I have a faulty bag, or I have a leak somewhere else. :( (Could I have damaged something by pumping too much air?)

Transmission: I always felt like the transmission was strange when I first got it, it normal driving it shifts so early, but if you put it in sport in makes the shift too hard (almost feels like my SMG transmission did in one of my M3's). I understands it adapts to your driving style and when I would go out and have some "fun" there were times where it shifted so hard if felt like something broke. Well this past Friday I was driving normal and between 3rd and 4th there was a long delay in the shift accompanied by a sound I can best describe as a belt slipping. It did this 3 or 4 times that night followed by the dreaded Trans failsafe message right before I got home. I looked it up in DIS but all I could find in the error was "shift too hard between 3rd and 4th." Next day the message was not there and I have driven it several times since then (not very long distances) and did not experience it again. Until last night, lol. I had some back and forth errands to run and it drove fine, but then I decided to put it in sport on the way home and right before I turned into my subdivision it slipped again between 3rd and 4th. No error message though. So it appears the issue only happens after the tranny fluid is warmed up and when you drive more aggressively.

Ok long post, and excuse my rant, just feel like I have the worst luck that I have 3 out 4 issues on a relatively low mileage example, one that I had thoroughly checked over before I bought it.

Cliffs if you don't want to read
-Rear air suspension is leaking air over night (mostly passenger side) even after air bags were changed. Where else should I be looking for the leak?

-After transmission is warmed up and driven remotely aggressively, shifts between 3rd and 4th are hard, and/or delayed accompanied by a noise in between. Do you think I should go ahead and change the filter and fluid to see if it helps or is it a lost cause? Could the valve body cause this issue? And what does an average rebuild cost? Don't feel like going to BMW and dropping half what I paid for it.

Thanks for any help. Not very happy with the X5 now, even though I still love the way it looks and drives for the most part, and is definitely a better fit for the family needs.

Air leak- try the soapy water troubleshooting method to locate the leak. If not at the bag trace the system connections back the the pump and go from there.

In some cases a fluid change will correct a transmission issue. It is more likely it will not. Cost of transmission repair obviously varies by shop. I suggest the first step is to go to a well recommended Indy shop that frequently repairs BMW transmissions for diagnosis rather than wade through speculation that will likely make you feel worse.

A 4.8 is a great choice based on what you have had in the past. To find one with only 80k miles and an extended warranty is good luck.

Thanks for the advise. I will try that on the air suspension. I already tried that on the new air bag, and did not notice anything, but it is tough to see and impossible to get the entire bag with it mounted.

I do plan to visit a transmission shop soon. One of my friends knows the owner of a big transmission shop in Nashville that has been in business for many years. I will find out if they have experience with the ZF transmission.
But just out of curiosity, what are most of you paying to have yours rebuilt? And if I take the transmission out myself would I save a lot (I've pulled the transmission before on my B5 S4 and my M5)?

Here are some screen shots of errors I have take from DIS and INPA.

Suspension (not getting an error anymore after I cleared it)

https://farm9.staticflickr.com/8620/...f5277977_b.jpgScreenshot 2014-10-17 17.50.50 by MikeandGabby, on Flickr

Transmission:

https://farm8.staticflickr.com/7506/...5e60c392_b.jpgScreenshot 2014-11-07 23.08.08 by MikeandGabby, on Flickr

https://farm8.staticflickr.com/7506/...0f801239_b.jpgScreenshot 2014-11-07 23.14.50 by MikeandGabby, on Flickr

https://farm8.staticflickr.com/7549/...8543dc11_b.jpgScreenshot 2014-11-07 23.17.29 by MikeandGabby, on Flickr

And one cell phone pic of the red demon. :rolleyes:

https://farm6.staticflickr.com/5594/...c5d18422_b.jpgimage by MikeandGabby, on Flickr

this was before I lowered it.

I have a 06 4.8is ,If You are adjusting the suspension You have to re-program the suspension and if You don,t it will effect the transmission and shifting TOO............., I wouldn't try to do that work on my own.
There is a lot going through the computer for the suspension and it is connected to the transmission.

Good looking truck. I'm kinda in the same boat with the same truck and the same finish. Bought it this summer knowing it had most of the 100K work done already, but now I've still been troubleshooting a shake that popped up about a month after I bought it. :/

What is your logic that adjusting the suspension height will change anything related to the transmission?

I would strongly suggest dropping the transmission pan and changing the filter / sleeve and gasket and then doing a subsequent drain and fill... it did wonders for my 6hp26 :)

I fully plan on doing it again at 200k!

My dealer replaced the trans vs. repairing it. Even under warranty, the warranty company sprung for new (only case is used SA said) trans when problems occurred. Also had 2 front bags replaced. You get all that sorted out and you will probably be in the clear.

Assuming the extended warranty expired and getting a new one is not an option for you?

So I do not have an extended warranty right now. The PO did. Sorry for the confusion. I could have transferred it but it only had a month or so left. I was offered one through my bank, but it was an extra $45 a month so I decided against it. Kicking myself right now. But this being my 5th BMW, it would have never paid off before (I did blow a motor in one of my M3's, but it was supercharged, doubt warranty would of paid for that, lol). It's a shame this has been less reliable than any of my M cars in just a matter of 2 months.

So I don't feel paying BMW 7 or 8K for a new transmission, I'm not going to pay almost half of what I paid for the truck. I'm trying to just figure out worst case scenario if the tranny is bad, what is the typical rebuild cost you guys are paying?

And yes I will try changing the fluid and filter first to see if that helps. And will be getting it checked out by a transmission shop if the fluid doesn't work. It would be nice if it was the valve body, because I think I could handle doing that myself.

Transmission Rebuild cost
 

I recently paid $3994 for the rebuild of a GM version transmission.
It had thrown a P0733 code.