I have a 2005 Buick Lesabre with the 3.8l engine. It has about 170,000 miles on it. The heater core isn't putting out heat. It has hot coolant going to it. My local mechanic said to put some Mr. Clean in & drive around for a couple of weeks to allow it to eat away the clog. Is this safe for the rest of the engine? Once it clears the clog would I do a complete flush & refill? Thanks for any advice.
No it's not safe for the rest of the engine he's crazy. If a power flush by removing the heater hoses and flushing it doesn't work you'll need a new heater car
Thank you, Scotty. I didn't think it sounded like a good idea. I'll give the power flush a try.
Best way is to reverse flush (flush it from the outlet side). I had this problem on my old Jeep and reverse-flushing the heater core fixed it very quickly. Didn't use any special equipment, just a garden hose.