Transmission temp too high?..
 

Yes my transmission is still acting up. Same issues, after driving for a while, I will come to a stop, I step on the gas, car would not move, with higher rpms, it would jump and there is your TRANS FAIL SAFE..(Transmission is rebuilt twice, module replaced and still happening)

There is also that delay between P, R, N and D issue)

So, I do more research, and find out many people with these symptoms had valve body wiring harness issues. The temp sensor would not work properly and tranny would overheat and go crazy.

So, I decide to check the temperature in many different ways. After a half an hour warm up, the INPA soft shows gearbox temp as 100C. I read 180f from outside using my infrared thermometer (not sure how reliable). Also, my basic error reader reads Transmission fluid temp as 91F.

Now, thats confusing, I would think that 100C is too high and in that case the temp sensor is reporting wrong.

A recent visit to a transmission mech, and the guy there said my tranny fluid is burnt (changed only 2 months ago).

What do you guys think..

Ozzie..

Are you using the correct fluid? As in OE fluid?

I am told by my mechanic that they used a high grade (brownish rather than red) transmission fluid.

I also had the heat exchanger and the thermostat replaced recently. Is is possible, still for the tranny to overheat (blocked hoses maybe?)

Ozzie..

Nah, that the wrong fluid. I think OE fluid is bright green from what I can remember. Or amber. Definitely not brown. Fluid should come from either straight from ZF or from BMW. I think you may have the wrong fluid in that sucker. Whether it is high grade or crap, it won't work in the gear box, which may be a slush box by now.

What about the temperatures?

That actually was my original question..

Ozzie

(As far as I know, whats being used is Dexron VI on these and thats red)

It's hard to say. there are too many variable. The temp may be accurate and does sound high, but may be caused from the wrong fluid not keeping the temp right. The outside temp read doesn't really mean much. I am sure the infrared thermo was accurate, but being it measure the outside of the case, too many variable there too. But not too sure why there is such a discrepancy between going through OBD and INPA when it is using the same computer.

But from the problems you described, especially that delay in gears, that sounds like a fluid problem and not heat related.

ZF fluid is Amber. And yes, it can cause your temp to fluctuate. And it is also important for the ZF box to be filled correctly. You might also have the wrong level in the trans, that can cook the oil, too low for instance.

Lots of variables here. two rebuilds and the thing is still messed up. I mean all your symptoms combined, sounds like your fluid is gone, your clutches are probably gone. Are you sure those that did the rebuild did it right, twice?

Yeah I agree. If the fluid is smelling burnt, then something is wrong. Especially if they did it twice??? Dextron is NOT the fluid that goes into these boxes. If thats what they told you is factory OE and it should work is not someone you want working on your E53. Hell I wouldn't even risk putting in Redline D4 in my box. ONLY ZF or BMW OE fluid. Period. Unless the shop doesn't mind continuing putting a new box in every 3 months, then sure, run the hell out of it.

Also, Like Slick said, wrong fluid for the right tranny, the burnt smell is either the fluid overheated, hitting the breakdown point and going bad, or there was some slippage in the clutches and the clutch material is overheating and burning the fluid.

I am just curious, if the tranny was replaced once, why was it done again?

Hey guys,

Firstly, these guys have been working with BMWs for a while, so I kinda hard to believe that they would use a wrong fluid in so many of them and get away with it.

Also, there is no burning smell, but another transmission place that I went to told me that it was burnt after a brief check up.

The transmission was opened up again after the rebuild because the transmission guy wanted to make sure that everything was ok. He said he did all the tests including pressure tests and no problems with clutches. This was done two months ago so, I cannot believe the clutches are gone already.

The car drives fine until it heats up and this problem happens when I am at a stop and try to move again. Once the TRANS FAIL SAFE happens, I can turn the engine off/on and everything is ok again for a while.

The only thing that the tranmission guy did NOT do well was to replace my valve body with a new one but a rebuilt one, so I still question that..

Transmission module come up with stall speed and gear check errors everytime, but thats it..

I can drive the car in manual mode without problems btw..

Thanks for the great input..

Ozzie..

After reading, I mean listen. I am not knocking the ability of your tranny guy or how good he is. I am sure he is very good at what he does but if he was so good, then why go to another tranny shop? Unless it was for a second opinion or you were stranded and that was the closest shop to you when you were on the road.

As for opening it up again just to see if everything is ok is really unusual. I mean if I owned a shop, I wouldn't dedicate hours of labor just to see if everything was ok. If there was a problem, then I would look into it, but just to have a customer come back for me to open up their tranny to see if things were ok seems a bit... wierd.

The X should drive fine at start up, because the fluid is thick and cold. Once the fluid warms up, it becomes thinner. Thats why Slick and I are suggesting the fluid may be wrong. Depending on the viscosity of the fluid, if it is too thin at operating temps, the clutches are going to slip, cause heat burn themselves out.

If he didn't do the valve body well, after he cracked it open a second time, why didn't you ask for him to replace it with a new one or another rebuilt one?

Also, after the tranny was done, did he reset the adaptation values?

That was one question I forgot to ask.

Again, do not take anything I saw above as me attacking your Mechanic. Again, I am sure he is very confidant and it is good that you trust him so well to back him up. I would just ask some more questions. Open ended questions. Such as with the fluid, don't ask, "Did you use BMW or ZF fluid? Ask, "Which fluid did you use, BMW OE/ZF or something else? If the answer is fuzzy or not BMW OE or ZF, then your problem starts there. Lets say you replace the fluid with ZF or BMW OE and it still doesn't fix the problem (Atleast the RIGHT fluid is in there so you don't have to go back right as the warranty on the tranny expires and find out a different fluid was used.)

I hope that makes some sort of sense in the mess I wrote.

Keep in mind that there's a thermostat for the transmission fluid.
It's located above the heat exchanged( 8 shaped black plastic with 3 hoses connected to it)
Normal temp is 82C mine is running hotter sometimes up to 106C
I get fault codes.
I already bought the thermostat as well as x-rings for heat exchanger(they are leaking once in a while) and now waiting for x-rings that go between thermostat and radiator,should be in next week.
If interested I can post the parts numbers.
I doubt that sensor is wrong,keep in mind that there's a ration for the spot: distance.... like 1 : 8,so you aren't measuring the actual spot if you are far from it

For a variety of non-performance reasons, BMW upped the engine operating temp from an acceptable mid-190s(F) to 225(F). this caused it's own batch of issues brought about because in the (most) X5 era, BMW's engine management systems were still running narrow band sensors and going open loop under load, so they had to band-aid with more knock sensors, etc.

Since the trans cooler is really just a little BS heat exchanger, your trans fluid will run well over 200F. Many, many in the trans field will opine that such temps are too high, and such temps shorten the life of the orings, and various plastic and rubber parts internally. Others will point out that the mfr knows best. Skeptics like me will say the mfr may know, but they ain't necessarily gonna tell all.

It's important to realize that this transmission was used in a plethora of makes and models NOT running BMW's temps nor the all-spendy secret squirrel sauce. (is my jaundiced viewpoint of BMW's band aids coming out yet?)

So yeah, your trans is running at what most would call high temps. But then so is everyone else's. Well, except mine. However, while the temps certainly aren't ideal for an auto tranny, this is probably not the root cause of your issues. I dunno (obviously, just sitting' over here) what the problem is, but if everything was up to snuff, then it'd work. In other words, the temps aren't the cause, but they aren't helping any.

Unfortunately, while not a big deal to throw on a stand-alone cooler, that's not the answer here. IF your fluid exhibits signs of heat distress, it's not because of operating temps, but may be a result of localized heating from slipping plates (your slip bang crash issues are slipping).

I wasn't saying your mechanic doesn't know his shit. I am saying anything could have happened, and you need to exclude oil. Now let's leave out the fluid brand for a second. Check your level. You issue really sounds like a pressure problem. Pressure loss will cause extra heat as parts aren't fully lubed, or engaged, or slipping. It's possible the valve body is screwed. But again it only happens when warmed up. And the fact that you are fine in manual mode leads me to think torque converter. Was that replaced?

Manual mode locks up the TC and uses completely different logic. The fact that it locks up the TC brings us back to pressure, which brings us back to fluid level, which brings us back to fluid speck. Now it is also possible your TC is toast, or the rebuilt unit is messed up. Chances are if your shop replaced it, the got a rebuilt somewhere. I've read of botched up rebuilt TC. Your mech probably can't rebuild it himself as that requires special equipment and skill set.

Sounds like the wrong fluid as a starting point. If it is burnt, you have other problems, which changing the fluid doesn't fix. Confirm that first. It isn't the viscosity that is important, it is the fluid friction properties which directly impact clutch engagement characteristics. Clutches slip, that makes heat, and that burns the fluid. Clutches also slip because of valve body problems, which it looks like you have experienced.

I don't think there is anything wrong with your fluid temperatures. They run hot. They are designed to.

Temperature sensors failing in the valve body wiring harness aren't related to temperature control. They are there to adapt clutch engagement pressures and times to the actual fluid temperature. So if the sensor malfunctions, the computer doesn't know if the oil is hot or cold and the electronically controlled shifts won't be correct.

Low oil level isn't likely the cause IMO. The transmission has had interventions more than once. Not likely the oil level would be wrong every time.

Manual mode doesn't lock up the torque converter. It just changes the shift logic (ie it doesn't shift automatically unless it needs to protect the transmission).

Recall that trans fail safe is just a computer message that means "this doesn't compute". The various sensor inputs don't add up to what should be happening, so the transmission throws up its hands and says it doesn't know what is going on, so it is going into a limp mode as a precaution. Just about anything could cause it, it isn't a diagnostic signal of any sort. Could be mechanical, hydraulic, or electronic.

You right JCL it doesn't lock up the TC. I need to stop drinking and posting at night. Lol.

Tisk Tisk Slick! lol.

Went to see Harvey yesterday, came home a bit plastered. So what's a fella to do when sitting on the throne and the head is spinning. Check the forums. Lol.

Hey guys,

I am certainly not defending my mechanic (he works with this tranny guy, who I am actually frustrated with) but I really do not know what to do anymore, and yes I still love my X5 and do not wanna replace it.

Here are all the details once again.

TC was replaced with a new one. I replaced the cooler and its thermostat myself but the two hoses going into tranny are old (could they be clogged?). I have replaced the TCM with a used one and same stuff kept happening. ABS module was rebuilt. I replaced the speed sensors. Transmission guy replaced the valve body with a rebuilt one (he said) and I still had the issues (I also have the delay from P,R,N to D, thats why I suspected valve body).

My wife just told me the car went into failsafe mode without even warming up after shifting from R to D, but after turning the engine off/on, everything is fine again.

Here are the errors I have on TCM (INPA) :

- Stall speed
- Gear check 2,3

No errors on ABS module, but there are some others on IKE etc. (I can post them if you think they are relevant)

I am going back to my mech on monday to check the tranny fluid and ask some questions..

Thanks for all the help, once again..

Ozzie..

Yeah, there is no way after two teardowns or one teardown and one check up that it should act that way. Completely unacceptable. Question him on the fluid and on resetting adaptations. Even after doing a tranny fluid and filter replacement, people complained the tranny was acting weird, but after resetting the values, all was good in the world again.

SO IMHO, if the tranny guy replaces the fluid and resets the values and the X is working fine, I'd find another tranny guy after the warranty has expired.

Hope you can get it straightened out Monday.

Great help guys, I really appreciate it!

I also did not know what exactly the temp sensor inside the transmission would do. I am assuming since the viscosity of oil changes with the heat, the sensor helps to make shifting adjustments according to that.

I am getting the oil checked tomorrow (correct? burnt?) and will ask for a new wiring harness installed.

Will let you guys know whats happening..

Ozzie..

Hey guys,

Another frustrating day, well kind of. Transmission guy insists that the temp sensor does not do much but just measure the temps in there to make sure the tranny would not overheat. He also insisted on everything is caused by the ABS module, but when I showed him the shifting delay, he agreed its a valve body issue!

So, he wants to replace my old one with a rebuilt one and I would like make sure that thing is functioning well. Is there any way to test the solenoids (measure each with ohmmeter perhaps?) and etc. on that thing?.

Of course, the car repeated the same shifting issues even without the ABS module, so there goes his theory. Lets see what he is going to come up with. Unfortunately my warranty is still with that id.ot so I cannot go anywhere without paying alot of money, although I am planning some calls to BMW NA to see what/if they can do anything..

Again, any help would be appreciated..

Ozzie..

Oi, sounds like a headache. Well, I know everyone hates to do it, but if it ain't right keep taking it back. Maybe, and I mean a big maybe. He will just get so frustrated and do one of two things. Either rip the entire sucker out and just get a another tranny from BMW, TC, etc. or compensate you by taking it to the dealership and handing it to them.

Now again, these are big maybes, I doubt they would happen, but it happened with me with another car. Had an issue fixed at an indy, went back 9 times over a 2 month period. Finally he raised his white flag and sent it to BMW and he covered the cost.

As for contacting BMWNA, they aren't going to do anything for you. You went to an Indy, not an authorized BMW repair facility. They are not going to want to hear it. Even if you are looking for a suggestion, they are just going to direct you to your nearest BMW dealership to have them take a look at it. Goodwill is never going to happen, but doesnt hurt to try.

Just keep at it with your Indy and just work with him. I mean if it is still under warranty, just keep taking it to him. I am sure you are already sick and tired of it, but so will he. If not now, he will later and maybe just give in.

Is it possible to test this rebuilt valve body (or its solenoids) before its put in? I am worried that I will still have similar issues after and will be a waste of time. Forgive me for being pessimistic after all.. :)

Ozzie..

I'm not sure??? I'm sure there is, but I don't know if you can just check the continuity between the valves and if you do have continuity, then that means it works? or you need to hook it up and actually see if the valves work or not. I don;t think I have come across a post that asked that specific question.

Is the X on the lift as we speak right now? Whats the tranny guy saying?

Well, maybe you were right after all. The transmission guy (kind of) said he gave up, and will send it to another place for another rebuild (for free).
I told him maybe it would be easier to put a new valve body on to test but he insisted the rebuilt one he put on should not have come up with same errors.

I hope they would check/replace everything this time..

Ozzie..

Hooray! Maybe the new guys can get it right.

You can test the solenoids by measuring the resistance but that would throw a code for the specific solenoid(s) in my experience. So not super helpful in this situation.

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Great news, I just save a bunch on my car insurance. lol.

Great news though. Lets hope the new guy knows what he is doing. Let's also hope the trans is still fine after all this.

Thanks, honestly, if I were them, I would put a new (or a BMW rebuilt) one in to avoid all the headache. I'll let you guys know once I get the car back next week..

Thanks again for all the help..

Ozzie..

Well, more, kind of bad news..

After the other transmission guy driving the car, they now claim that its the transfer case slipping and putting the car in 'N' intermittently. So I am looking for a used one here..

What do you guys think?

Ozzie..

Can you please put your car info into your signature. I don't remember what year or model your car is, and I don't feel like re-reading all the above to find out. Thanks.

Sure.. (its a 4.4 X5 01, but hopefully it will show in my signature as well..)

So pre face lift. Ok, just open the transfer case up and replace that chain. There is a DIY on here. Search for transfer case removal with pics. Quite a few have done it.

And I don't get how its slipping. Is it the splines in the shaft that are slipping?

If the chain is stretched, you should be able to hear it slapping around off throttle to sudden throttle.

Thanks for your help again. This is kind of urgent so I looked around and found a used one here in Chicago for $700 (NV 125). I am hoping to get it replaced tomorrow.. (And if taking the transfer case out requires lifting the car, its not possible for me to do anyway. Otherwise I would love to DIY)

And yes, there is a slapping sound (I have been hearing that for a while and wondering if it was related to tranny issues, actually) during quick acceleration, very loud and annoying..

Thanks again,

Ozzie..

Update : After car being back for a new transfer case and another transmission open-up, today I am being told that the forward clutch drum (A) was cracked and about to be replaced. Sounds familiar? Could that be the whole reason for all the problems I was having?

I am hoping to pickup the car tomorrow, with all the issues solved..

Ozzie..

Did the new shop find that or the first one?
Sounds like it could solve the issues.
I would save the old t-case incase the used one fails because it didn't sound like the typical chain problem those have.

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I am guessing it was the other transmission place this i.iot took the car to since he kind of admitted he was out of ideas.

I think the old t-case is gone already as the core..

Ozzie..

Update : Be ready to say wow. The new place the inapt transmission guy (I am hardly holding myself from mentioning his name) took my car to actually found the transmission issue once they opened it up. Its the Forward Drum (A) cracked! How the heck did this j.rk missed this, hard to believe!

So, car goes back to the j.rk to fix, he receives the new part, and he does not do any work on it for a week, keeps promising me that it would be done in 2-3 days several times..

Today I call him, since he promised me the car would be done, he gave me another excuse, so I told him to return the car to my original mechanic immediately, or the police would get involved.

Now, the car is back to my mechanic (who outsources transmission work to this j.rk) and they already opened up the transmission to replace the part, I am hoping to have it back in a day or so.

What would you guys do? Its just unbelievable what kind of a guy I had to deal with..

I am hoping this new part would solve the problem or I may choose to take them to court..

Ozzie..

Update : Good news so far! I got the car back today, they said after testing the transmission with some type of paint to see where it leaks (which was supposed to be done in the first place 6 months ago, I guess). They saw the leakage was between torque converter and the pump thru some sort of shaft? They replaced the torque converter and the pump all together (Shaft as well, or its just attached to the pump). Today I drove the car for couple of hours and no problems! So I am about the believe that its done..

Thanks again for the input from everybody..

Ozzie..

Out of interest what temps is the transmission running at now it's all working well?