Q: Oil is a light brown don't know if it's water or coolant

If it is water alone, that would just simply be due to too many short trips perhaps combined with a stuck open thermostat. The solution is to change the oil more frequently. Engine coolant would be a problem though. Do you have to frequently replenish the coolant level? If not, then you might not have a coolant leak. There are tests for anti-freeze in the coolant including blotter type tests that you can perform at home. If you do have a leak, the lower intake manifold is just one possible source. Cracks in the head or block can cause these leaks, too. To rule a leak in or out, and pinpoint the source, the recommended service is a coolant leak diagnostic. If you request that service, a certified Mechanic, dispatched by YourMechanic right to your location, will get this promptly resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.