If you suspect that transmission fluid has been mistakenly used for engine oil, it is important to have the oil changed as soon as possible to avoid potential engine damage. Here are some signs that may indicate that transmission fluid has been used in the engine:
1. Color: Transmission fluid is typically red or amber in color, while engine oil is usually brown or black. If the engine oil has turned black after only three days, it could be an indication of transmission fluid contamination.
2. Consistency: Transmission fluid is typically thinner and has a lower viscosity than engine oil. If the engine oil feels thinner than usual, it could be a sign of transmission fluid contamination.
3. Smell: Transmission fluid has a distinct smell that is different from engine oil. If the engine oil has a strange or unfamiliar smell, it could be an indication of transmission fluid contamination.
4. Performance: If the engine is running rough or making unusual noises, it could be a sign of transmission fluid contamination. Transmission fluid is not designed to withstand the high temperatures and pressures of an engine, and its use can lead to engine damage.
If you suspect that transmission fluid has been used in the engine, it is important to have the oil changed as soon as possible. You should also consider having the transmission fluid flushed and replaced to ensure that all traces of engine oil are removed.