Clunky Automatic Transmission

I’ve got a 1999 VW Lupo 1.4 with 36000miles on it. It’s a 3 speed automatic. (the Lupo is a hatchback version of the VW Golf, sold in Europe) Generally the car’s in excellent shape but has had some minor issues one would not expect from such a low-mileage car. My mechanic suspects the car sat idle for an extended period, years maybe. He also thinks a previous owner may have used ethanol in it.

When the starts up there is often a sharp “clunk” when the transmission shifts from first to second. It never happens from 2nd to 3rd. I try to avoid the clunk with slow acceleration. Is this serious? Could this be a simple case of bad ATM fluid? Advice welcome. Thanks!

“Bad fluid”, as in…“did I put the wrong type of fluid into the trans”?
"Bad fluid", as in…“is the fluid overdue for changing”?

The answer is “yes”, to both possibilities, but only you can answer the question completely by checking both your service records and your dipstick.

If the fluid is any color other than a pinkish red, and if it has a burnt odor, then you have bad fluid.
If the fluid wasn’t changed during the past 3 years, then you most likely have bad fluid.

One of the problems with buying low mileage used cars is that the previous owner may have ignored the elapsed time factor when it comes to maintenance. On the basis of elapsed time, this car should have had the trans fluid (and filter) changed 4 or 5 times in its 15 year life. While you can’t turn back the hands of the clock to undo lax maintenance, you can (hopefully) extend the life of this transmission by doing a fluid & filter change right away, using the correct specification fluid.

Also…instead of “sitting for years”, this car may have been driven less than 3k miles per year by the previous owner, and that can be…ominous…if that owner was not very diligent about oil changes. That type of usage is usually a situation of an owner who does only short-trip, local driving, and that is very bad for an engine–especially if the oil isn’t changed every 6 months. Unless you can confirm that the car got oil changes every 6 months, I would suggest an immediate oil change, followed by two more at one month intervals in order to try to clean out accumulated sludge from that engine.

I didn’t think automatic transmission fluid had a “mileage or time” change recommendation. I thought it was primarily mileage based.
Just curious.

I have always seen it expressed as “every 30k miles or 3 years, whichever comes first”.
I suppose that the elapsed time factor is because the additives in trans fluid deteriorate over time, just as the additives in coolant do.