The most likely causes are:
* Internal Transmission Problem: This is the most probable culprit. Excessive fluid pressure is usually a symptom of a malfunction within the transmission itself, such as:
* Worn or failing pump: The transmission pump might be failing, creating excessive pressure.
* Blocked or restricted passages: Debris or a blockage in the transmission's internal passages can restrict fluid flow, leading to increased pressure.
* Valve body problems: A malfunctioning valve body can fail to regulate fluid pressure correctly.
* Clutch pack failure: A failing clutch pack can cause excessive pressure buildup.
* Overheating: Consistent overheating can damage seals and components, contributing to fluid pressure issues.
* Incorrect Fluid Level (Less Likely): While you're experiencing the opposite – *too much* fluid is being forced out – a rare possibility is an initially incorrect fluid level, *followed* by an internal problem creating more pressure. However, this scenario is less likely given the description of the fluid being actively pumped out.
What NOT to do:
* Don't keep adding fluid: This will only exacerbate the problem and potentially cause further damage.
* Don't drive the car: Continuing to drive will likely lead to catastrophic transmission failure.
What to do:
1. Have the transmission professionally diagnosed: This is crucial. A qualified mechanic with experience in automatic transmissions should inspect the car. They'll likely need to:
* Check the fluid: Not just the level, but also the condition (color, smell, presence of metallic particles).
* Inspect the transmission for leaks: Rule out any external leaks before focusing on internal issues.
* Perform a pressure test: This test will measure the transmission's internal fluid pressure under different operating conditions, providing vital information about the problem's location.
2. Prepare for repairs: Depending on the diagnosis, the repair could range from relatively minor (e.g., replacing a faulty valve) to major (e.g., a complete transmission overhaul or replacement). This is likely to be an expensive repair.
In short, this is a serious transmission issue. Ignoring it will almost certainly lead to complete transmission failure, resulting in a costly repair or replacement. Get it checked by a professional immediately.
