Aut. Transmission stuck in neutral when hot?

[moenbeer]

Hi all

I got a C5 2.0 HDI from 2004. aut. Works fine. - But when I get stuck in heavy slow moving traffic, the transmission goes into limp mode. When stopping, it' get stuck in neutral. - No matter what i do.. Putting in Park, Manual etc etc... it stays in neutral. - But if I rev. the engine to 2000 rpm, it kicks violent into drive... So i can drive it again a few meter until next full stop.. then it's stuck in neutral again. - I found out that keeping the revs up, while breaking with my left foot stops it from getting stuck in neutral more or less.

Any idea what could be causing this? - I got a Lexia, but it' wont read any code for the car. ( thats another problem to be solved )

It's only in slow traffic this happens. So I only have this problem 1-3 times a month. - But's annoying. Otherwise there are no problems with this transmission, works fine going to work - back home - or going for a 3 hour drive on the freeway.

Tried to check the oil level.. But with no oil stick... and a only a small fill hole thats hard to get to. I haven't been able to control if there is a lack of fluid. - ( this was soooo much easier on my other cars... ) - Plan is to change the oil. - Once I figure out how to fill it up.

any tips apprecitated.

[moenbeer]

UPDATE:

The transmission is slowly leaking fluid. - I found out when changing the oil as a last attempt to fix the problem, before going on a long roadtrip. - There was only 1 liter of black fluid in the transmission pan, when i pulled the plug. After refilling with 4 liters of ATF ( damn expensive.. ) The transmission works again. - and it made a long trip from denmark to germany in heavy, slow summer traffic with no problems. And back again.

The transmission still leaks, so I had to refill 2 liters after one year. - but its cheaper than trying to fix the transmission seal. - The car is worthless and soon, they might not allowed older diesel cars in the city where I live. - So it might get scrapped in a few years, or exported.

For anybody else with this problem. - You will need a special square socket head bit for the upper and lower plug. - I just grinded a normal hex socket down, so it was square and fit the plug.

Buy 5 liters of the ATF oil required for a C5. - I use the brand Pentosin ATF-1 which according to the shop would be the right one for a C5 longlife transmission.
Get a funnel, plus some hose and maybe a bit of kobber/steel tubing. ( around 3 inches )
Remove airfilter tube- The one going from the airfilter box to the trottlebody.
Behind the transmission selector cable is the plug. - It can be hard to see and reach. - It's a big round plug, with a square hole in the middle. - Make sure you clean the area around the plug.. You don't want to get dirt into the transmission.
Use your headsocket. bought / homemade - with a extender and loosen the plug. - Now take your funnel with either a build in long nose, or attache a hose to it and some tubing in the end. - Make sure it can go into the hole.. Now that we are sure, we can fill new oil into it...
Now raise the car up using either the hyd. system, or lift or.. whatever.
Place a oil pan/catch under the transmission. - using your head socket, remove the plug. drain the oil.
Replace the plug.
Now fill it with oil according to your manual. - Mine took 4,5 liters of oil for a oil change.
remove funnel, put the plug in. - reattach airfilter tube.
And you are done. - It takes around 1 hour to do. If you got tools and oil ready.

[xantia_v6]

For the record, which seal is leaking on your transmission?