Are 2004-06 more reliable than <=2003

[Turbo_Bimmer]

Still collecting informations for my future car swap.

Is the 6spd tranny better than the 5spd? I also read that the 4.6 tranny was build with stronger parts. Does that make the 4.6 a longer living transmission?

Is the valvetronic reliable, or it is one more thing that can fail?

And finally, the transfer case. Right now, my 325xi 2002 has the old TC like the 1st generation X5. It is reliable, but, handling wise, I would like to experiment a X-drive as next vehicle. Clutches are wear items, and I don't think the X-drive is an exeption. Are there X-drive owners that had worn or failed clutch pack in their TC?.
Are there rebuild parts available in the rebuild market?
I read also the there is a bearing in the X-drive TC that is not available anywhere, true?

Thanks.

[JCL]

The newer models are only more reliable because they are newer, and generally have fewer miles. A well cared for 2003 will be more reliable than an abused 2004.

6 speeds are better in that they provide better fuel efficiency. No difference in power handling capability. Additional clutch packs aren't a concern. Newer transmissions such as the 6 speeds may have more software issues, or not. There are more electronics involved.

The 4.6 isn't known to have a greater incidence of transmission problems AFAIK, but it is known to have torque converter problems. Those TC failures can take out the transmission due to debris.

None of the various transmissions have shown failure modes related to too much power going through them. They have lots of failure modes, but overheating isn't one of them. The exception to that is the early diesels in the UK and elsewhere (not NA), which were upgraded to the ZF transmission from the V8 to better handle the greater torque.

There can be failures associated with valvetronic on the 4.4, but I would say the benefits outweigh the risks. I wouldn't hesitate to choose a valvetronic engine over a non-valvetronic engine, myself.

Clutches in the ATC transfer cases haven't proven to be an issue, as long as you have the correct OE fluid in there and the actuator motor is functioning correctly. Actuator failures have caused clutch problems due to slipping, but the clutches don't tend to wear out by themselves. It is a proprietary transfer case, so there are limited parts and aftermarket options available for service. Plan on dealing with the dealer if you have a problem, but don't expect it to break. I think the benefits of the x-drive variable torque transfer outweigh any downsides to having to buy more expensive OE fluid, or worry more about failures.

There is an issue with the output shaft splines from the transfer case. There is an AC condensate drain right above them. The splines can rust, and they don't engage very far. The splines can fail. There is a fix involving a 3rd party modified output shaft with rebuilt splines, slightly longer. It has been reported to be very successful for those who have failed those splines. Good info if you do a search, the supplier is RaceMalibu on this board.

Other than that issue, I don't think anybody worries about the transfer case in their X5s. I certainly didn't, and I don't worry about the x-drive TC in my X3 either.

Overall, reliability is related somewhat to design, somewhat to initial assembly, somewhat to care and maintenance, somewhat to complexity, and somewhat to luck. You can only control a few of those. You can do your due dilligence on a prospective purchase, you can check maintenance records, etc. One of the things you can control is complexity. Newer models are more complex, and vehicles with lots of options are more complex. Trouble is, people tend to like their options. If you search through this board, you will see a lot of posts about devices that are really electrical gimmickry IMO. Those are the things that tend to fail more often than basic mechanical components. You will read a lot more about transmission software than transmission clutch packs. My choice is to buy the simpler version of the vehicle I want, where I can (no Nav, few technology options) but for others, the ability to synch their phone with the iDrive is why they buy the car. It is up to each individual.

[imola38]

Originally Posted by JCL

The newer models are only more reliable because they are newer, and generally have fewer miles. A well cared for 2003 will be more reliable than an abused 2004.

6 speeds are better in that they provide better fuel efficiency. No difference in power handling capability. Additional clutch packs aren't a concern. Newer transmissions such as the 6 speeds may have more software issues, or not. There are more electronics involved.

The 4.6 isn't known to have a greater incidence of transmission problems AFAIK, but it is known to have torque converter problems. Those TC failures can take out the transmission due to debris.

None of the various transmissions have shown failure modes related to too much power going through them. They have lots of failure modes, but overheating isn't one of them. The exception to that is the early diesels in the UK and elsewhere (not NA), which were upgraded to the ZF transmission from the V8 to better handle the greater torque.

There can be failures associated with valvetronic on the 4.4, but I would say the benefits outweigh the risks. I wouldn't hesitate to choose a valvetronic engine over a non-valvetronic engine, myself.

Clutches in the ATC transfer cases haven't proven to be an issue, as long as you have the correct OE fluid in there and the actuator motor is functioning correctly. Actuator failures have caused clutch problems due to slipping, but the clutches don't tend to wear out by themselves. It is a proprietary transfer case, so there are limited parts and aftermarket options available for service. Plan on dealing with the dealer if you have a problem, but don't expect it to break. I think the benefits of the x-drive variable torque transfer outweigh any downsides to having to buy more expensive OE fluid, or worry more about failures.

There is an issue with the output shaft splines from the transfer case. There is an AC condensate drain right above them. The splines can rust, and they don't engage very far. The splines can fail. There is a fix involving a 3rd party modified output shaft with rebuilt splines, slightly longer. It has been reported to be very successful for those who have failed those splines. Good info if you do a search, the supplier is RaceMalibu on this board.

Other than that issue, I don't think anybody worries about the transfer case in their X5s. I certainly didn't, and I don't worry about the x-drive TC in my X3 either.

Overall, reliability is related somewhat to design, somewhat to initial assembly, somewhat to care and maintenance, somewhat to complexity, and somewhat to luck. You can only control a few of those. You can do your due dilligence on a prospective purchase, you can check maintenance records, etc. One of the things you can control is complexity. Newer models are more complex, and vehicles with lots of options are more complex. Trouble is, people tend to like their options. If you search through this board, you will see a lot of posts about devices that are really electrical gimmickry IMO. Those are the things that tend to fail more often than basic mechanical components. You will read a lot more about transmission software than transmission clutch packs. My choice is to buy the simpler version of the vehicle I want, where I can (no Nav, few technology options) but for others, the ability to synch their phone with the iDrive is why they buy the car. It is up to each individual.

Expertly written post and I 100% agree.

-Ben

[AZX54.4]

JCL said it best. I personally think these X5's are very individual in terms of maintenance. I own two of them. A 2002 3.0 which has only required regular maintenance and a 2005 4.4 which has required a lot of work in my past year of owning it. The best thing you can do is look at the history. Has it been reliable and the maintenance it has required. As far as the valvetronic system. I had to have the valve cover gaskets replaced on my 4.4 and it was a whole lot more work to get to because of the valvetronic system. My 4.4 has the air suspension and it has all been replaced. If you find one with air suspension I would check into if it has been replaced because this is something you most likely would have to work on in the future. Bottom line, check the history of the car. If you are buying from the owner and not a dealer ask the owner what their history has been with the car. If it has been reliable or not. Good Luck!

[Quicksilver]

I agree with JCL "The newer models are only more reliable because they are newer, and generally have fewer miles. A well cared for 2003 will be more reliable than an abused 2004." Other than that theres no way to tell.

[Turbo_Bimmer]

Thanks everybody for the replies.

So it seems that maintenance is the thing to check. I'll try to find one sold by an invividual with some service records.

And since prefacelift == facelift in term of reliability, I will have more choice which is good. I like the newer ones for the X-drive, but also like the older ones for the 4.6 options: Imola red, Estoril blue colors, and the sportier trim. I hope the 4.6 is not the equivalent of ///M when it's time to buy parts!

JCL, I smiled when you talked about the front driveshaft having problems with the splines due to rust and limited engagement. My 1988 325ix, and all other ix of that era, have the same problem. I would have thought that BMW had change the desing, to go with a slip yoke like the rear! For the E30 ix, there is also a shop that manufactures driveshafts with longer splines. Personnally, I made a 1/2" aluminum spacer that I installed between the differential flange and the driveshaft to give an extra 0.5" of spline engagement. Studs are required instead of bolts due to limited space though. May be that would work as a preventive mod on the X5 also?

Finally, I find it pleasant to read on this forum. It seems to have more mature people, and they take time to answer with valuable content, with complete sentences, and real words

[fraserp]

so i take it from all the response that the manufacturer does not clear up the known problems and kinks in the performance of the vehicle in the new models when they are introduced. just the same old $$%^^ in a newer body. am i right ????

[JCL]

Originally Posted by fraserp

So, I take it from all the responses that the manufacturer does not clear up the known problems and kinks in the vehicle when they release a new model. Instead, they just carry on with the same old problems in a newer body. Am I correct?

No, I don't think so. There are some issues that carry on over model year changes, but there are different views on that. Some people have failed window regulators every year or so, and have replaced them all, some more than once. Some believe that BMW window regulators are very weak. Myself, I have never experienced a failed window regulator in any of my last 5 (recent) BMWs. Maybe it is because I was taught when I was young to never slam the door, particularly when the window was all the way down and not supported by the tracks.

Others think that the oil separator valve is a poor design. I have never had a problem with it. Trouble is, it doesn't deal well with many short trips and the condensate never burning off. So people who have those driving conditions have repeat failures. Others (including me) who make sure that the engine gets hot enough to burn off the condensate have never had an oil separator failure. I did get a buildup of condensate once, so I did an early hot oil change. It's called preventative maintenance. And, that was in a 318 with a four cylinder, it didn't produce much heat.

You can slag any manufacturer if you want to, they are not that different, but they generally address the problems that cost them money and customers. They don't change their design principles because people want to use the vehicles for other than how they were designed.

Maybe you could clarify what you meant by carrying on with the same problems through subsequent models.

PS: fixed your post.

[JCL]

Originally Posted by Turbo_Bimmer

Finally, I find it pleasant to read on this forum. It seems to have more mature people, and they take time to answer with valuable content, with complete sentences, and real words

We try. Welcome aboard!

[MINIz guy]

Originally Posted by Turbo_Bimmer

Finally, I find it pleasant to read on this forum. It seems to have more mature people, and they take time to answer with valuable content, with complete sentences, and real words

E46Fanatics.