Here's why this happens:
* Vacuum Leak and Pressure Differential: The intake manifold creates a vacuum to draw air into the engine. A failed gasket creates a leak, and the negative pressure in the intake manifold can suck in fluids nearby. The transmission dipstick tube is in close proximity to this area and sits in the transmission fluid, making it a convenient source.
* Common Failure Point: The intake manifold gasket on these engines is known to be a common point of failure, particularly as they age. Heat, vibrations, and age degrade the gasket material, causing it to crack or become brittle.
Other (less likely) possibilities:
* Cracked or damaged engine block: While less likely, a significant crack in the engine block near the intake manifold could allow transmission fluid to seep into the intake. This is a much more serious and expensive problem.
* Improper PCV system: A severely malfunctioning Positive Crankcase Ventilation (PCV) system *could* potentially contribute to the issue, but this is secondary and wouldn't be the primary cause of transmission fluid in the intake.
Important Note: Driving the car with transmission fluid in the intake is extremely dangerous. The fluid can damage the engine's cylinders, piston rings, and catalytic converter. It's crucial to get this issue resolved immediately.
What to do:
* Stop driving the car immediately.
* Have a mechanic inspect the vehicle. A visual inspection will likely reveal the failed intake manifold gasket, particularly if there's evidence of fluid leakage.
* Expect a repair involving replacing the intake manifold gasket. This will likely require a professional mechanic, as it involves removing the intake manifold. The mechanic should also determine why the gasket failed and address the root cause to avoid future issues. Consider replacing other seals and gaskets in the area while you're at it.
Ignoring this problem will lead to extensive and costly engine damage. Professional repair is strongly recommended.
