X5 4.4 - Sludge in engine and oil filter housing... help!

[JCL]

Originally Posted by sunny5280

This is just a restatement of the post FSETH linked to. There you said you felt the chances of dislodging sediment are slight. I agree with this. There is a possibility but I don't see it being very high. Nor do I see any evidence the dislodged sediment, in the slight case it occurs, results in transmission failure.


I am assuming you're replacing the fluid with the recommended fluid. Which makes this point moot.

It is not just a restatement. The chances of a fluid change causing a transmission to fail are slight, but still very real. You have to weigh that against the benefits of clean fluid. What makes you think that clean fluid will make the transmission last longer? There is no data to support that point of view. I say the chances are slight, because posters regularly change their fluid, don't have a failure, and then conclude that this is proof it was a good idea. It isn't proof, it is simply proof that they dodged the bullet, and good for them in that case. I won't change my own transmission fluid because I see no reason to. The transmission failures we have seen haven't been caused by worn out fluid.

Talk to anyone who has worked in a transmission shop, and they will confirm that they regularly get overhauls caused by unneeded fluid changes. Doesn't happen with every fluid change, but it is a very common failure mode. Sludge that wasn't hurting anything gets flushed into the valve body when you refill it and restart it, on the initial pressurization; that sludge then clogs an orfice, and causes an actuator or sensor to fail.

If you are replacing the fluid, I assume you are using the correct fluid specification. That doesn't make my point moot, however, as fluid changes viscosity over time. That is known to the engineers, and the transmission adapts to the fluid as it ages. There are feedback sensors on things like clutch delays, etc. When you put thinner (correct, but still thinner) fluid in, you can get failures. Again, transmission mechanics are familiar with this. It has been discussed on this site by BMW techs.

All of this said, do whatever makes you happy. If you think you want to change the fluid, just change it. If it causes a transmission failure, you can always tell yourself that it was going to happen anyway, and that you didn't initiate it. If it doesn't fail, you win as well.

[sunny5280]

Originally Posted by JCL

It is not just a restatement. The chances of a fluid change causing a transmission to fail are slight, but still very real. You have to weigh that against the benefits of clean fluid. What makes you think that clean fluid will make the transmission last longer? There is no data to support that point of view. I say the chances are slight, because posters regularly change their fluid, don't have a failure, and then conclude that this is proof it was a good idea. It isn't proof, it is simply proof that they dodged the bullet, and good for them in that case. I won't change my own transmission fluid because I see no reason to. The transmission failures we have seen haven't been caused by worn out fluid.

We're in agreement there is a slight risk accumulated sediment can be dislodged. However I have seen no evidence to suggest dislodged sediment results in significant numbers of transmission failures. Therefore, in the absense of data to the contrary, the risk is so minimal as to make it a non-issue.

As to the benefit lubricants breakdown and become dirty over time and their ability to provide the protection they once did is reduced. Thus increasing wear on the components.

Given this I believe replacing the fluid has benefit that far exceeds the risk.

Talk to anyone who has worked in a transmission shop, and they will confirm that they regularly get overhauls caused by unneeded fluid changes. Doesn't happen with every fluid change, but it is a very common failure mode. Sludge that wasn't hurting anything gets flushed into the valve body when you refill it and restart it, on the initial pressurization; that sludge then clogs an orfice, and causes an actuator or sensor to fail.

I spoke with my mechanic about this and he recommends replacing the transmission fluid at regular intervals. As a matter of fact I had never heard of transmission failures resulting from fluid changes until I started reading BMW forums. I have seen no data to support changing the oil correlates into any significant number of transmission failures. Your reasoning makes sense but I think it is applicable in only a small number of cases.

If you are replacing the fluid, I assume you are using the correct fluid specification. That doesn't make my point moot, however, as fluid changes viscosity over time.

If you use the correct fluid why would the viscosity be relevent?

That is known to the engineers, and the transmission adapts to the fluid as it ages. There are feedback sensors on things like clutch delays, etc. When you put thinner (correct, but still thinner) fluid in, you can get failures. Again, transmission mechanics are familiar with this. It has been discussed on this site by BMW techs.

All of this said, do whatever makes you happy. If you think you want to change the fluid, just change it. If it causes a transmission failure, you can always tell yourself that it was going to happen anyway, and that you didn't initiate it. If it doesn't fail, you win as well.

This is a specious conclusion. If, after changing the fluid, the transmission fails how do you know it wasn't about to fail regardless? I think we're all aware of people who, in a desperate attempt to avoid a rebuild/replacement a transmission, hope changing the fluid will fix a symptom of a failure. Conversely if the transmission doesn't fail how do we know it was luck and not preventative maintenance?

[JCL]

Originally Posted by sunny5280

We're in agreement there is a slight risk accumulated sediment can be dislodged. However I have seen no evidence to suggest dislodged sediment results in significant numbers of transmission failures. Therefore, in the absense of data to the contrary, the risk is so minimal as to make it a non-issue.

Have you ever worked overhauling transmissions? I suspect not. It isn't a non issue to those of us who have, but it may be to you. That's cool.

Originally Posted by sunny 5280

As to the benefit lubricants breakdown and become dirty over time and their ability to provide the protection they once did is reduced. Thus increasing wear on the components.

No argument. Only issue is, is it relevant? Are X5 transmissions failing due to lubricant quality? Not according to the posting history on this board and others. Sensor failures, actuator failures, programming failures, are all unrelated to fluid quality. They are at the root of many early transmission failures. Changing the fluid won't improve your odds.

Originally Posted by sunny5280

Given this I believe replacing the fluid has benefit that far exceeds the risk.

Then you should change your transmission fluid. You are the only one who will live with the consequences, so just do it.

Originally Posted by sunny5280

As a matter of fact I had never heard of transmission failures resulting from fluid changes until I started reading BMW forums. I have seen no data to support changing the oil correlates into any significant number of transmission failures. Your reasoning makes sense but I think it is applicable in only a small number of cases.

My reasoning is based on working in a shop. I can't tell you what to do, just that I won't change my own transmission fluid. I do believe in preventative maintenance. I just believe that in the case of the X5 transmission, the risks outweigh the benefits.

Originally Posted by sunny5280

If, after changing the fluid, the transmission fails how do you know it wasn't about to fail regardless? I think we're all aware of people who, in a desperate attempt to avoid a rebuild/replacement a transmission, hope changing the fluid will fix a symptom of a failure. Conversely if the transmission doesn't fail how do we know it was luck and not preventative maintenance?

I wasn't referring to those cases. I was referring to the multiple cases where a transmission worked fine, up until soon after it had the transmission fluid changed. It happens too often. Technicians in transmission repair shops know about it. You can discount it if you like. It is the reason that those of us who have rebuilt transmissions make judgement calls on whether to change the fluid in this case. I think there is a small chance of a fluid change causing a failure, overall. I think there is even less likelihood of degraded fluid causing a transmission to fail. Look on this board for all the posts that start off "FML, my transmission failed, and wouldn't you know it, I even changed the fluid recently". If you choose to take the chance, no problem, rest easy in the knowledge that your transmission probably won't fail due to a fluid change anyway. Just don't expect it to last longer, that is my point.

[sunny5280]

Originally Posted by JCL

Have you ever worked overhauling transmissions? I suspect not. It isn't a non issue to those of us who have, but it may be to you. That's cool.

No I have not. Nor do I work rebuilding engines. That doesn't mean I can't make an informed decision about whether I should change the engine oil. I've spoke with my mechanic about this prior to having the transmission fluid in my X5 changed. He's well aware of this ubran legend and doesn't buy into it. That, combined with a complete lack of supporting data, is enough for me.

No argument. Only issue is, is it relevant? Are X5 transmissions failing due to lubricant quality? Not according to the posting history on this board and others. Sensor failures, actuator failures, programming failures, are all unrelated to fluid quality. They are at the root of many early transmission failures. Changing the fluid won't improve your odds.

They could be. But I'm not arguing pro transmission fluid replacement (though I think it's a good idea). I'm arguing I have seen no evidence to support changing it increases the likelyhood of failure. And so far you've provided no such data either. Just anecdotes stating you've seen transmissions fail after the fluid was changed. It is your theory the transmission failed because of the fluid change but you cannot offer anything other than a theory. What is surprising is you continue to say there's a slight chance it could happen. Of which I agree. However slight does not make a correlation.

Then you should change your transmission fluid. You are the only one who will live with the consequences, so just do it.

Already done.

My reasoning is based on working in a shop. I can't tell you what to do, just that I won't change my own transmission fluid. I do believe in preventative maintenance. I just believe that in the case of the X5 transmission, the risks outweigh the benefits.

That's fine. I'm not here to convince you to change your fluid. You feel there's no benefit. I disagree. Fluids break down. They get dirty. Replacing them is good maintenance, IMO.

However I did ask what the risks are to changing the fluid. So far the only risk I've received is that there's a slight possibility doing so could dislodge some sediment. Which I'm sure there are some examples. Not enough to offset the benefit of changing it...IMO.

I wasn't referring to those cases. I was referring to the multiple cases where a transmission worked fine, up until soon after it had the transmission fluid changed. It happens too often. Technicians in transmission repair shops know about it. You can discount it if you like. It is the reason that those of us who have rebuilt transmissions make judgement calls on whether to change the fluid in this case. I think there is a small chance of a fluid change causing a failure, overall. I think there is even less likelihood of degraded fluid causing a transmission to fail. Look on this board for all the posts that start off "FML, my transmission failed, and wouldn't you know it, I even changed the fluid recently". If you choose to take the chance, no problem, rest easy in the knowledge that your transmission probably won't fail due to a fluid change anyway. Just don't expect it to last longer, that is my point.

But you can't say the transmission failure was due to changing the fluid (unlikely, IMO) or some other issue of which a transmission fluid change was a last ditch effort to avoid a costly transmission rebuild/replacement.

You're also forgetting that a transmission shop isn't going to see all the transmissions where a fluid change was performed and no failure resulted. So your sample is limited almost exclusively to those transmission which failed.

[Mikedd]

Originally Posted by JCL

Have you ever worked overhauling transmissions? I suspect not. It isn't a non issue to those of us who have, but it may be to you. That's cool.



No argument. Only issue is, is it relevant? Are X5 transmissions failing due to lubricant quality? Not according to the posting history on this board and others. Sensor failures, actuator failures, programming failures, are all unrelated to fluid quality. They are at the root of many early transmission failures. Changing the fluid won't improve your odds.



Then you should change your transmission fluid. You are the only one who will live with the consequences, so just do it.



My reasoning is based on working in a shop. I can't tell you what to do, just that I won't change my own transmission fluid. I do believe in preventative maintenance. I just believe that in the case of the X5 transmission, the risks outweigh the benefits.



I wasn't referring to those cases. I was referring to the multiple cases where a transmission worked fine, up until soon after it had the transmission fluid changed. It happens too often. Technicians in transmission repair shops know about it. You can discount it if you like. It is the reason that those of us who have rebuilt transmissions make judgement calls on whether to change the fluid in this case. I think there is a small chance of a fluid change causing a failure, overall. I think there is even less likelihood of degraded fluid causing a transmission to fail. Look on this board for all the posts that start off "FML, my transmission failed, and wouldn't you know it, I even changed the fluid recently". If you choose to take the chance, no problem, rest easy in the knowledge that your transmission probably won't fail due to a fluid change anyway. Just don't expect it to last longer, that is my point.

We did a poll on here on that very subject of failing transmissions after fluid change. Mind you it was far from statistically accurate but I was very surprised to see that no one had reported a failure after fluid change and 10K mles after. I was really surprised and the more I asked the more of "urban legend" it seemed to become. Certainly out of proportion to reality.

[JCL]

Originally Posted by sunny5280

But you can't say the transmission failure was due to changing the fluid (unlikely, IMO) or some other issue of which a transmission fluid change was a last ditch effort to avoid a costly transmission rebuild/replacement.

You're also forgetting that a transmission shop isn't going to see all the transmissions where a fluid change was performed and no failure resulted. So your sample is limited almost exclusively to those transmission which failed.

I believe I can, if my shop did the only maintenance to the vehicles in question, and knew the vehicle history. I have already discounted the cases where changing the fluid was a last ditch effort to avoid transmission repair.

The shop in question (in my case) was a general repair shop, that did not do transmission work exclusively. We overhauled some tranmissions, and worked with specialist shops that could do it cheaper in other cases. There is a clear correlation with increased failure rates after fluid changes, it wasn't just our shop. That said, clean fluid is a good thing. It just didn't always make transmissions last longer (which was the primary reason that owners wanted to change transmission fluid, to increase the life of their transmissions)

[JCL]

Originally Posted by Mikedd

We did a poll on here on that very subject of failing transmissions after fluid change. Mind you it was far from statistically accurate but I was very surprised to see that no one had reported a failure after fluid change and 10K mles after. I was really surprised and the more I asked the more of "urban legend" it seemed to become. Certainly out of proportion to reality.

You are correct that it had no statistical significance. What I found surprising was that some members who had failures after changing the fluid, and had posted about them, didn't respond to the poll.

[macadamia]

[QUOTE=ArNarX5;730663]So I changed the oil for the very first time on the 03 4.4 I just bought two weeks ago and to my surprise.... WOW: wow: talk about sludge everywhere in the in the engine and filter housing! I was disgusted. <snip>

I recommend you get an oil analysis done when you change the oil the next time. Blackstone Labs will send you a free kit and analyze your oil for $22.50. There are a bunch of guys over on the m3forum.net who have used this service and the info they get back is very useful. Here is a link to one of their analysis threads.

[Schrei-x5]

500 for a tranny fliud change?!!! HAHAHAHA its a few bolts and filter anyone could do it

[X5 Meister]

I wouldn't say that. In fact, that statement is stupid at best and shows your ignorance. The proper fluid for that transmission alone will cost over $300. There is a pretty detailed procedure of what you should do before, during and after refill. The instructions are certainly not trivial.

Originally Posted by Schrei-x5

500 for a tranny fliud change?!!! HAHAHAHA its a few bolts and filter anyone could do it