Auto trany light

[frankie]

After starting my car, my auto transmission light went on and i couldnt move the car in 1,2,3, or drive, only in reverse. so i had a flatbed tow me home and the light was still on and couldt drive froward. An hour later i turned on the car and the light was off and the forward gears worked. whats going on here? I know ill probably need a new tranny soon but i dont know if i should get a used one, rebuild, or put in an M3. i was also considering an manual swap but i dont know what the price range on something like that goes. what do you guys suggest?

[Marv17]

well if you need a tranny i have a used one from my old setup when i had the M44. It worked perfectly fine. No issues. No codes thrown. and the gears were perfect. i did a swap (to a 6 cyl) and no longer need it.

[frankie]

So will that tranny fit an m42 engine? I was also thinking about swapping the 4 cylinder to the 6. How much does a swap like that go for? Also, how much will you let the tranny go for? How many miles does it have on it?

Thanks

[Marv17]

it will fit the M42. I believe the M42 and M44 share the same trannies as do all the E36's EXCEPT for the M3 and some 328 as they have a ZF which is a bit bigger.
I just want like $80-$100 for it. Nothing much. Its just sitting here collecting dust. Not sure on the mileage as I am not certain if its the original. But the clock had 170k on it if i can remember correctly.

A swap can go anywhere between $2k to $6k, depending if you are doing it yourself or having a shop do it. The ///M shop charged someone $8k; they did all the labor and sourced out some parts needed. I bought myself a wrecked car for $2k that Jesse found me and did it at home.
Anything is possible when money talks.

[frankie]

Well I went against what people say and I changed the tranny fluid and filter and the light went off and I can drive it. So I'm going to see how it does and ill let you know soon if I need it. It does seem like its got a few miles on it since mine went at 140k. If mine goes out it'll go pretty soon so ill let you know. Is that swap price is including the s52,tranny, new drive shaft and all that jazz? I'm a little concerned about the engine light going on after a swap like that.

[frankie]

would it be possible to get the number off the tranny and the one off the car just to see if that tranny is the original one which has the 170K on it

[familytruckster]

Could be a bad connection somewhere, or some junk in the trans filter or a stuck valve in the VB. Heck my car kicked the trans light on and stopped shifting when I had the MAF disconnected.

[frankie]

whats the VB or MAF and where are they located?

[familytruckster]

VB = Valve Body, it's in the trans and controls the shifting.

MAF, Mass Air Flow- it's a sensor under the hood in the intake tract. It would have thrown a check engine light also if that had happened.

Any chance of getting the codes read? Might shed some light on the problem.

[frankie]

well when the car went up on the flat bed and was at an angle, the tranny light turned off. will it still throw up a code? ill check it but i need to get obd1 to obd2 adapter.

[familytruckster]

maybe just really low on fluid?

Trans codes don't come up on the obd port...At least I don't think they do.

[Monolith]

Originally Posted by familytruckster

maybe just really low on fluid?

Trans codes don't come up on the obd port...At least I don't think they do.

The stored tranny codes don't show up on the OBD port. If the tranny code is severe enough, however, it will set an engine code which will be reported on OBD.

Would it not move forward easily (as if it's in 3rd gear - which is limp home mode for the tranny) or not at all?

If the tranny code is not severe enough, simply turning off the car for 1-2 minutes will clear it and allow full operation of the transmission. A check engine light is usually lit afterward and would require clearing.

The fact that the tranny error light went away on an incline suggests low fluid.

[frankie]

so i checked the obd 1 and got 2 codes, one for knock control regulation and the other for the throttle position sensor none of which were for the tranny. the codes for the 95 318ti doesnt seem to have any transmission codes.

After having the gear light turn on and the transmission neutralizing itself i decided to go ahead and change the tranny filter, ATF, and gaskets. After doing this, the light went off but my transmission started to slip at take off.
It shifts up just fine but if i come to a stop pretty fast i have to wait a second or two for the tranny to grab 1st again. if i dont wait and i hit the gas the engine just revs and the tranny seems to be in neutral till it grabs. it only does this if i stop pretty fast.

What can this be?

i know there are 5 solenoids in the atf pan that are responsible for some shifting. they vary from torque converter to shifting. there are multiple ones for shifting. could one of these have burned out?

[frankie]

i also didnt see any brown sludge in my pan (just some normal wear on the magnet) so i think the clutches are still good and when i step on the gas going up hill the car responds just fine ( no slipping/ loss of power) so i thing the actual gears and clutches are fine

[Monolith]

The slipping is classic symptoms of low fluid level. Recheck your fluid level doing the following:

1. car level
2. engine running
3. turn A/C on
4. shift slowly, pausing in each gear and return to park
5. check fluid level when fluid is at 86 deg F (30 deg Celsius)

During the summer, ambient temperature can even be above the low fluid check temperature, so you have to do the check quickly. The dealer will use a GT1 to monitor the fluid temp sensor. If you don't have this, try to use an IR meter on the valve body pan and get it at least to 80 deg F (fluid will be hotter than this). Some people use their hand and wait until the valve body pan feels "warm" to the touch. Just giving you some different options here.

The a/c is switched on to increase the rpms slightly to distribute the fluid better.

During the fluid check, you just want a small stream coming out. I suspect if you follow the above, you will get another 1/2 to 1 quart more of tranny fluid in the transmission.

Tranny codes are stored in the TCU and not reported via OBD. You need a BMW form of diagnostics connected to the car to read the tranny codes. If a tranny code is severe, it will be reported to the DME which then can be read by the OBD.

Let us know how it works out.