95 540i Transmission/Lockup Solenoids What? Where? How?

[Slowey]

My 95 540i Automatic has been experiencing some shifting wierdness.

1st symptom: On the highway, cruising 50-65 MPH, car feels like it is shifting between gears...upshift...downshift...upshift...downshift. My initial workaround was...drive faster. At 75 MPH, no problems. We have had a bit of a cold snap here, and the problem has become more pronounced.

2nd Symptom: When shifting from Auto Drive to Sport 4 there is a noticeable shuddering once the car is in 4th. But it is not always there. Sometimes it shudders while in 4th, sometimes it cruises along smoothly.

3rd Symptom: This usually happens when I hop in the car first thing in the morning. I will start her up, drive up to the gas station (less than a mile). Fill her up. Start her up. Put her in Drive and she is bucking like a bronco while I am in Drive with the foot on the brake. I have found that punching the accelerator for a short burst from as stop makes this one go away immediately and it doesn't return until the start up and short drive part.

4th symptom: Now that it is colder, I have noticed something truly unsettling. On the highway, at 55-60, foot off the gas say about 2000 rpm, when I step on the gas, the tachometer moves up a couple hundred RPM instantly. I take my foot off the gas, it drops the same amount instantly.

I have already done the air intake reseal. When I got the car, I had the CEL fuel mix lights, and replaced the air intake seals. Also, oil in the plug wells, and replaced the valve cover gaskets. This was probably the real culprit, and CEL went away. Also much more zoom zoom. Thanks to all the great info and posts on here. Cheers for that. But anyway, I am certain it is not a leaky air intake or engine issue.

When it is cold, sometimes my tachometer doesn't move until the car warms up. But I doubt this explains symptom 4. I have been reading about similar symptoms on here and have the Bentley manual. I plan on doing the ATF and Filter. I know that makes a lot of things get better.

So in searching around here I have started to think it is a lockup solenoid problem. What is puzzling me is the solenoids that I have seen in posts. I have read about solenoids that I will see when I remove the ATF sump. I gather these are the "Valve Body Solenoids" that are mentioned in the Bentley.

So....$64,000 question is, What is the lockup solenoid (if it is different than the Valve Body Solenoid)? Where is the lockup solenoid? How do I determine if the lockup solenoid is my problem (stall speed test?)/replace fix the lockup solenoid if this is my problem?

Bonus Question: Based on the symptoms above, is it there an expert opinion regarding what the most likely problem(s) are that are causing this?

Finally, Six speed swap is on nowhere near my radar screen at the moment.

[xatlas0]

Have you checked the fluid levels?

[bdejong11129]

Have you checked the fluid levels?

+1 to that. Your initial symptom of the tranny at a certain speed feeling like it was changing gears is what I had for a little while in mine. I changed teh fluid, filter, gasket and made sure to properly fill it and it went away. I used Castrol Multi Import ATF for the change and it worked great for me. I had abouot 180k on the trans when I did it.

[skylinergtr]

if the shifting is ever feeling "too rough" another thing that can affect it dramatically is the rear subframe bushings. My rear subframe bushings were torn, and my auto transmission seemed like it was shifting much harder than before. Now with new bushings it shifts much much smoother. I also plan to take the car to a transmission specialty shop later on in the new year to get a complete system flush, new filter, and gasket.

[m60b30530i]

Well does the car shudder when coming out and exiting over drive ?

If so that would be your lock out solenoid
Similar symptoms with my 530 brought to BMW stealer ship a while ago, they diagnosed as bad lock out solenoid, a tranny specialist could most likely diagnose this issue for you.

[napuli]

Thanks so much for the excellent description of your problem. I have been experiencing the exact same problems for about a year now. The 3rd problem has become pretty consistant and is the one that really makes me worry about the transmision. What I don't understand is why it only happens after the short start/stop/start sequences? Maybe it has something to do with the ATF being cold and puting the car in P after a short drive. Anyhow, do you have any opinions as to what maybe causing the bucking? One thing I am thinking is that the tranny maybe stwiching back and forth between second and first very fast or something like that.

[K Fox]

One more thing to consider is that is may be starving for fluid occasionally due to a blockage in the filter, or possibly the filter collapsing internally. It's been noted before. Depending on how many miles you have and if the fluid or filter were ever changed, it may make a world of difference to do so yourself. Just remember, if you do the filter change yourself, make sure you get a stock filter - it will have 'Filtran' printed on it. The cheap ones are the most notorious for collapsing under use in the tranny. As far as which solenoid is which, I'm not sure, but there are a couple of companies that sell rebuild kits for the valve body, and if you were to call one of them they should be able to tell you which one it is. Plus, if you're thinking of doing any of this work yourself you should seriously consider getting at least the new style check balls inside that valve body - If it's going to be apart you might as well do it. If you only get the check balls and the gasket it's like $10 or something silly like that. looking back on the rebuild I did, I would go that route next time and only get the CB's. My $.02

Fox

[mrgraybeard]

Greetings from a longtime lurker. I did a valve body rebuild on my 5hp30 trans at about 150K and it resolved a 4-5 hunting issue I had, mostly around 45-50 mph. The rebuild kit includes a couple of major valves, a bunch of springs and the infamous check valves. It's not an enormously difficult project, especially with the numerous DiY writeups you can find online. It'll probably take an evening to accomplish, IME. The kit cost about $140 from Kirt Koeller at Auto Sports Unlimited.

You've probably read this elsewhere (oops, like in the prior post), but get a filter from BMW rather than the aftermarket. Kirt has the filter at a fair price too.

You can certainly try the fluid/filter change first. You'll get only about one-third out by just draining the pan, so if you have to go back in, you can figure you're just going to freshen more of the fluid.

If the fluid is low, you must have a leak somewhere. A common spot is the bushings on the shift selector rod. They're small and cheap but can be a bitch to install. I used a piece of a plastic straw to slide them onto the selector shaft.

All that said, hunting up around 55-65 mph on relatively flat terrain makes me wonder if the engine is delivering all the power it should. Are the spark plugs fresh?

I do remember my car wanting to drop into fourth occasionally at 65 if I went from flat highway to an upgrade with steady throttle. I got in the habit of punching it a little as I approached the grade to get it to shift in the flat. As you said, cold weather made the issue more pronounced. No longer a problem.

Oh, forgot to mention, I didn't change any of the solenoids, just the parts in the VB kit.

[napuli]

What about replacing the entire valve body? I found one for about $500.

http://europeantransmissionscom.x-shops.com/shop/product.php?productid=16263&cat=693&page=1

[K Fox]

What about replacing the entire valve body? I found one for about $500.

http://europeantransmissionscom.x-shops.com/shop/product.php?productid=16263&cat=693&page=1

Well, if you're not keen on doing the actual rebuild yourself then it's definitely an option. Plus, it'll keep the job to an easy couple of hours to open it up and swap the VB - not hard at all. That said, I think $500 is a little high - I remember someone telling me that I could get the VB already rebuilt from the people with the kits for only about $350 or so. Maybe call Kirt and see - I know he was the one being referred to. He really has a good rep with people here in the forum, so I'd start there. FWIW, I got my rebuild kit from Eriksson Industries as at the time of my purchase I couldn't find anything about Kirt and I had forgotten his name and contact info. I'd ask Kirt before buying from that link, probably be happier in the long run as he can also advise about the issue your having, not just sell the parts to you. :)

Fox

[mrgraybeard]

What about replacing the entire valve body? I found one for about $500.

http://europeantransmissionscom.x-shops.com/shop/product.php?productid=16263&cat=693&page=1

That may be the route you want to take -- Auto Sports Unlimited had a rebuild for $350 a few years ago, IIRC, but $500 might be the going rate at this point. A fully rebuilt valve body would ensure all the solenoids are working properly in addition to the hydraulics.

The thing I like about Auto Sports is that you can call Kirt toll-free and he'll spend time talking out the transmission problems with you. It's good to know a business will provide support and advice, whether or not you spend money with him.

I'm thinking that the basic rebuild was a good move for my trans at 150K. The main pressure valve was clearly more loose in its bore than the replacement. Many of the springs were more compressed than their replacements. And while the body was clean and the check balls weren't worn, the big channel plate gasket had grown brittle with age and heat.

I got the car with 82K, and changed the fluid out three times before doing the VB at 150K. But the original fluid was filthy when I first drained it and the pan magnet was loaded with metal grit. Which is odd, because the trans had an aftermarket filter in it when I first opened it up. I assume someone replaced the filter, them pumped the original fluid back in and topped it up. It was leaking fluid at the selector shaft bushing and harness plug when I got it.

Basically, the 5hp30 is a very robust transmission -- it's the control parts that can run you into trouble. My feeling is, stay on top of that stuff and the transmission will last for a long time (mine has 184K at the moment).

Fox, Eriksson welded some new coolant line nipples onto my trans cooler this year after I stripped one. I think I dealt with Nate over there -- he was very helpful. Probably saved me $400 vs. a new cooler.

[Slowey]

Thanks to all for the informative responses.

I had the car in a trusted shop with BMW knowledge and experience. Their suggested solution was replace the transmission, estimate $9000. They topped off the transmission fluid as an alternative, said it was a liter low. They suggested doing the incremental fluid drain/fill/drain/fill/drain/fill. Either way, the car is shifting smoother now than before, but all of the symptoms are still there. I was wondering why they didn't recommend any of the things I have seen on this thread. They said that the transmission could not be flushed. Since I knew this and also knew that many people here recommend dropping the ATF sump and replacing the filter (as does the Bentley manual), I was kind of surprised that they didn't suggest it.

I would like to do this myself to save the bucks, but I don't have access to a lift. Does anybody know of a transmission specialist in the Washington DC area that is educated in the 5HP30?

[Slowey]

I was poking around my auto parts supplier website and I found an interesting article about these transmissions ans how difficult it can be to diagnose problems. The takeawaynthta I got was inline with a lot of suggestions to replace the valve body assembly. I figured the article may be helpful to others with tranny problems so I am posting the link.

http://www.olyonline.com/techtips/bmw_icbmwtransmission.asp