Greetings! My name is Steve, and I own a 2004 Cadillac DeVille base model, four door sedan. The engine is a 4.6L V8 32 Valve Northstar Engine. I love this car! I've owned this car since 2005 when it had 20,000 miles on it. Today the car has 133,500 miles on it. It's been a great car for me and my family of four. Since 2016 the car has had a small coolant leak. I had the car pressure tested back in 2016, and the leak was so insignificant the mechanic told me just to drive and enjoy the car. I've had to add about a half pint of coolant every 3 to 4 months. I recently took the car to the auto shop to have the leak "re-evaluated". The mechanic said I have a problem, the car lost 8 pounds of pressure over 24 hours. The mechanic cannot determine the source of the leak and wants to do exploratory surgery and look at both the intake manifold and head at a cost of approximately $750.00.

It has been suggested to me I instruct the mechanic to proceed with replacing the seals on the intake manifold, and that the leak may reveal itself. If a leak is found in the manifold, there may be no reason to look any further in the head. I don't want to be penny smart and pound foolish, and not look at the head if there's good reason to do so. I mean the oil is clean and pure, no signs of water. There is no excessive white smoke or anything coming out of the exhaust either. The car does give off a sweet coolant odor when parked after driving say 30 minutes down the road.

So the question is do we proceed with replacing the seals on the intake manifold, and see if the leak reveals itself, or just let the mechanic do his thing and look at both the intake manifold and head? Your suggestions, recommendations please? Thanks, Steve.