Auto Trans Experts - please chime in

[Arragonis]

My auto box has started to become a pain in the obvious. Its a mix of all sorts of nonsense - this is my A6.

Full history - I bought this car with 82K on it and it had Audi "Long Life" service which means basically the (dreaded) first owners only serviced it when the computer went "ding" and told them to do so. It has a full service history though based on this requirement from Audi themselves.

I have had the trans fluid changed at 82K and the garage got 2/3rds of it out which is pretty good apparently. They also did the re-learn step although I am wondering about this.

The box has never been happy though.

It "bangs" between gears when cold like a learner driver using a manual for the first time - come off the (house) drive accelerating gently and "bang" 1st-2nd and then "bang" 2nd-3rd.

When warm the up changes have tended to be smooth until recently where the change from 2nd to 3rd is very rough - the revs rise between the change and then the box catches up and switches into 3rd. 3rd to 4th seems OK as does 4-5 and 5-6. The same is true of down changes - 3-2 is very rough but 6-5, 5-4, 4-3 are quite OK.

Swapping from D to R also results in a "bang" every now and again too. If I pause from D - N - R then it is much smoother.

So any advice - is my GB OK and maybe the TC is Beggorah'd ? A reprogram from the garage, low fluid (how do I check ?). etc.

Ta.

EDIT - this is my first Auto as an owner.

[Superfuelgero]

Could be fluid. On the lifetime fill vw/audis, you basically fill till it overflows. The eurovan (T4) guys like to change the lifetime fluid every 40-50k miles. You really need to have a vag-com if you plan on keeping the car around for awhile.

My suggestions:
-1 fluid swap since you're already overtime to do so (with another relearn)
-2 still nothing, vag com
-3 shows nothing get the VB redone using the sonnex mods. Its a diy r&r, fairly skilled skill to mod. Just be careful with the solenoid wiring.

fyi, a "relearn" is just holding the pedal to the floor with the key on, engine off.

[cptsideways]

Is it a multitronic?

If so they are notorious for failing, there is an ecu inside the box itself

[Superfuelgero]

The multitronic pos cvt was a fwd trans, the quatto should be a 09l tip.

[Arragonis]

Originally Posted by xntrx

Could be fluid. On the lifetime fill vw/audis, you basically fill till it overflows. The eurovan (T4) guys like to change the lifetime fluid every 40-50k miles. You really need to have a vag-com if you plan on keeping the car around for awhile.

My suggestions:
-1 fluid swap since you're already overtime to do so (with another relearn)
-2 still nothing, vag com
-3 shows nothing get the VB redone using the sonnex mods. Its a diy r&r, fairly skilled skill to mod. Just be careful with the solenoid wiring.

fyi, a "relearn" is just holding the pedal to the floor with the key on, engine off.

Its a Tipchronic - standard 6sp Auto.

Fluid has just been done at 82K, now on 85.

VAG-COM scanned a couple of weeks ago with nothing with the GB - a "lazy" glowplug seems to be the only mech fault.

What is the VB Redone ?

Thanks.

[Superfuelgero]

VB = valve body. There are modifications to flow and springs that help (sonnex mods).

[Arragonis]

Hmm. OK.

Just to be totally annoying the box has behaved perfectly for the past couple of days...

[yoyoyoda]

Sounds totally like fluid.

If the fluid is too low then the torque converter cannot fill up and it will be choking on air, a really bad way to transfer power from the engine to the gearbox.

http://www.youtube.com/watch?v=pTfipsejqS0

If the fluid is black in color then yeah, change it, and the trans filter.

Usually when transmissions go bad they make a big BANG which can be heard from inside of the car.

But I did have a Ford Auto trans which had a sensor inside it gone and it made it smash into 1st-2nd-3rd.

Seeing as that I was quoted $1,000 for a repair on that one I decided to get a reconditioned one for $650 fitted in shop, I ended up selling the car soon after.

Your options:
#1 Drive it up a hill, stop the car, put your foot on the brake and put the t-bar into neutral or park, then put it back into Drive and take off, if it doesn't want to engage or move forward while going up a hill then you definatley have a fluid level problem.

To top it up, make sure you've driven the car for 10-15 mins, drive it to the auto repair shop and buy the proper fluid for it, then drive it back home and park it on a flat surface, probably the road.

Pop the hood, pull the transmission dipstick out and rub it on the grass to clean it, feed it with two hands back into the transmission and pull it out again to check the fluid, if its on COLD or LOWER then put in about 100mL to 250mL of trans fluid and check the fluid again some other day.

Never EVER check transmission fluid when the car has been sitting for a while, always check it right after doing a short drive. If you check the trans fluid when the engine and trans are still cold then you will ALWAYS get a wrong reading on the dipstick of "cold or hot" or somewhere inbetween.

So if we warm up the engine and transmission, all of that fluid is gonna get sucked up into the parts of the gearbox and is now going to register zero on the same dipstick. a bad thing. It SHOULD be registering at least cold, or hot.

So its a good idea to make sure you check the stick when the transmission is warm, and NEVER when its bone cold.

My best guess is that the fluid level has been checked incorrectly during the last service.

Second option:
#2 Get it checked for free at an auto transmission place.

Third option:
#3 Take off the sump of the transmission and check the fluid for any metal shavings inside of it, replace the gasket and bolt it back up and refill it with sufficient fluid.

If you find metal shavings in the transmission sump then you've got problems.

[Arragonis]

@Yoyoyoda

Many thanks for that response - I had forgot about Eric, I watched his clutch video a few years ago - a DOH! on my part. I also watched his auto trans video just now too.

Firstly your tests - yep, it will pull away on a hill no problem at all. Even a really steep one like the one just under Edinburgh Castle. I have had instances where when I slip from D to R to get onto the drive (uphill) the revs have risen but no progress backwards. A quick slip to N and then back to R usually solves that one - has happened maybe 2-3 times so far.

The fluid and filter are fresh, I had them changed when I got the car at 80K miles. The garage that did it (I trust them) did explain that not all the fluid would be replaced as some does not come out which is what I found online about it. They changed the filter and cleaned out any metallic "fluff" (shavings) from the magnets in the sump - apparently from what I have read there will always be some

They also took time to do the "adaption" process although as they were short-handed that day and I think they might have rushed that element rather than keep me waiting - I was happy to wait but... I did wonder if that was the issue but I have run it myself to check. Again they did explain that to me rather than hide it which is what most garages would do.

Audi state the gearbox is sealed for life, but that is a myth like Audis never rust Because of this I don't think there is a dipstick on the trans based on numerous Google and Google Image searches. There is a level check bolt and a filler bolt - the idea being you fill it up until the fluid pours out but this is hard to get to.

I will get the fluid level checked though this week and see what happens.

As I posted above though it has behaved more or less perfectly for the past week or so - smooth most of the time, the occasional 2-3 "lunge" where the revs rise in 2, pause at the same rate, and then suddenly drop as 3 comes in and the car lunges forward.

One other issue I have noticed is that sometimes when in D at a standstill there is a rumbling noise in time with the engine at idle so coming from the trans maybe. When I shift to N it goes away. It only happens sometimes though. The last time this happened I stopped somewhere for 10 mins and then restarted and it was fine again for the rest of the day. Engine mount maybe, exhaust perhaps vibrating against the floor at certain temps ? Who knows.

Enjoyed the brief blob of snow we had with AWD though

[yoyoyoda]

Originally Posted by Arragonis

@Yoyoyoda
Audi state the gearbox is sealed for life, but that is a myth like Audis never rust Because of this I don't think there is a dipstick on the trans based on numerous Google and Google Image searches. There is a level check bolt and a filler bolt - the idea being you fill it up until the fluid pours out but this is hard to get to.

We have a similar scenario down here in AUS with a Ford Falcon EL model which came out with a sealed gearbox with the exact same method of refill as yours has. It is well renowned for failure and trouble.

The problem with the lack of a dipstick is that backyard mechanics will then shy away from replacing the transmission fluid on a regular basis, the exact problem which was meant to be solved by incorrectly filling an auto transmission actually just made the problem worse because then people just didn't bother paying for services. It backfired on the repairmen :P

96 EL Falcon gear change jerk - problem? - Ford - Automotive

I will get the fluid level checked though this week and see what happens.

This is the perfect place to start off with diagnosis.

One other issue I have noticed is that sometimes when in D at a standstill there is a rumbling noise in time with the engine at idle so coming from the trans maybe. When I shift to N it goes away. It only happens sometimes though. The last time this happened I stopped somewhere for 10 mins and then restarted and it was fine again for the rest of the day. Engine mount maybe, exhaust perhaps vibrating against the floor at certain temps ? Who knows.

Yeah could be that, have you done a thorough inspection of the transmission mounts? maybe something isn't bolted up properly.

If it were my car I would be underneath there with a flashlight checking out everything.

Failing those easy fixes...

It needs a proper inspection, solenoids can and do fail, it could also be a dirty connector somewhere on the outside of the transmission which is making an intermittent contact and is losing contact when you shift.

On my toyota a neutral selector sensor has a 20 pin connector where the silicone rubber seal around the inside of the connector had burst and let its silicone fluid run out down to the connector, clogging up the pins.

I disconnected the battery and cleaned out the connector with degreaser then made up another seal with black silicone from a tube.



Good luck