I am having an intermittent coolant leak. A few days will go by and then a small puddle under the engine. My 85 car has 135,000 miles. Replaced the thermostat last year. Any thoughts on what may be causing this? Is it OK to drive the car long distance w/o running into any trouble? Thanks for your input.

Way too little info to give any specific answer.

Short answer is: Your engine is aluminum. Aluminum engines do not like to overheat. Overheating = expensive. Leaking water can lead to overheating. Long trips can lead to leaking significant amounts of water. Feeling lucky?

As to the leak. Where is the water?

Front of engine? Under transmission? Under radiator? To the side?

Possible culprits are: Radiator, water pump, heater core, and all hoses. You've also got a heat exchanger under the windshield where the wipers park.

Clean the engine, and identify where the water is coming from.

Jim

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14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles

Thanks Jim for your input. The engine is not overheating at least for now. The leak is in the middle front of engine. Why the intermittent nature? It is baffling.