user 723923490

I am experiencing a problem where once out of every 8 or 9 times I drive my car the Tiptronic shifts very harshly. Almost feels like dumping the clutch on a manual car. 1st to 2nd is not bad but the rest are quite severe. I usually drive in manual mode but auto is the same.
I was hoping the problem would go away with a full fluid flush and filter change but it persists. Shutting the car off for a few hours usually clears it up. I would think a stuck solenoid but it never clears unless I shut the car off and leave it. It will not clear itself no matter how long I drive.
Ideas?
TIA
Allan

justin-in-athens

How long ago was the fluid/filter change?
How did the old fluid look?
What kind did you replace it with?
You only get about 4l out of the total ~10 it holds out with a simple pan drain.

I would look at performing another drain, and maybe some Liqui-Moly ATF additive.

user 723923490

The flush and filter change was last winter. I did pump all of the old fluid out until it ran red with new fluid. I am confident I got it all out. The fluid looked like it was over due but not excessively.
I am going to try the Liqui-moly before I do anything else.
Thanks

geolab

no additives please.
First check if you did the ATF fluid filling correctly !!!
Fast check, go for a ride, keep engine running and put Trans in Neutral
Check level at first mark.
IF OK....
You have to change the Tiptronic differential fluid, and your Tiptronic will be smooth
We all pinpointed the procedure here on rennlist, a quick search and all will be good.
good luck

user 723923490

I went thru the whole process as you described. Used a pump to get the fluid out per the manual. Took my time with the fluid level with engine running etc. Also did a fluid change on the diff. Problem existed before the change and still persists. Intermittent, maybe every 8th or 9th time I take it out. Feels like a solenoid is getting stuck. It shifts HARD.
I am pretty brave with DIY but according to the shop manuals, getting at the solenoids is terrifying and I wouldn't know what to look for anyway.

user 723923490

I was considering an additive, run for 500 mi, then another fluid flush and new filter.

geolab

Which fluid out with a pump ? the ATF ? if so

lets go again through this.

Drain the Tiptronic through the bolt in middle left of pan, on the magnetic bolt, there is metal residues...clean and wait about 2 hours if you have time for all ATF to drain.
Unbolt pan removing all bolts around. remove pan, remove rubber seal, clean pan well.
unbolt filter from Tip switchboard, if you have a new filter good, if not, soak old filter in diesel fuel for an hour (DO NOT CLEAN FILTER WITH BRAKE CLEANER OR any solvent) just diesel
check the filter rubber seal if it is on filter, or still on switchboard, wipe the seal clean.
let the Solenoid switchboard drip oil until it stops.
Usually, what I do is spray a tad of WD40 on switchboard, and air pressure blow it quickly and thoroughly, used to tape a large plastic around the gearbox, not to soil all surrounding with ATF, goggles goggles goggles
remount filter with seal,
remount pan
fill with three to four liters.
Start engine, position in Park
wait 10 minutes,
with engine running, place gear shift on R for 2 seconds to pressurize, and then on Neutral.
Top up ATF level to first lower mark WITH ENGINE STILL RUNNING.

For differential, unplug upper and lower hex bolts, let drain...clean bolts (magnetic)
re-bolt, and fill until it spills , approx 0.9liters with W90/120
regards
george

P-daddy

^Wow George, your step by step should be stickied or posted on pcarworkshop, if not already.

user 723923490

I appreciate the input. I did everything as you described with the exception of the fluid FLUSH. I used the Porsche manual with my own improvised pump as shown. You cannot get the fluid out of the lines and cooler without a pump. My fluid level is good. Please take my word for it. New filter was installed along with a new pan gasket. Do you have any experience removing solenoids?
Thanks
Allan

geolab

hello,
I am talking about the transmission box, you are talking about the cooling system of the box
lets talk about the transmission itself please.

ps, to flush the cooling system, I use a pressurized ATF cleaning can , looks like you've done that cleaning


did you change the DIFFERENTIAL fluid also ???

geolab

oh, the solenoids do not get tired...either they work , or not
changing the solenoid is a piece of cake

user 723923490

Dif fluid changed at the same time per post #5.
What is the procedure for changing solenoids? Are they expensive?
Last thing that I can think of is a piece of debris stuck somewhere. If I remove the solenoids and clean them up do you think this would help?
TIA

geolab

if you did all we discussed, yes , you could proceed to clean the valve body
remember, solenoids are electro-mechanical servos that you cannot service
the hardest part I had in removing the valve body from the TIP box, is the electrical plugs from the solenoids.
For the body to go down, you should unplug the electric small loom
and there is a plug on the top part of the body, to un-plug that one, you have to lower the body and slide your hand inside before detaching.
You are a DIYer you said. All is doable, but for this diy, take loads of pictures, and you need space to place each part in sequences in a highly oily environment
Porsche do not service the box, but I know I have a factory manual for this box somewhere

drb930

Hi Geo,

Any chance you would have a .pdf copy of the manual?

Thanks,
Dave

user 723923490

This looks like a project for next winter. I will start a thread and document the process. If anyone has any resources, photos etc. I would appreciate it. I would like to see what one of these solenoids looks like. For now I am going to research & plan.
Thanks to all, especially Geo.
Allan