DASeneca

OK, so here's he picture... 2013 Scab, 5.0, 140,000 miles. Water pump bearings failed. It was a quiet death, no overheating, no scary noises, just started leaking. Being the ex-dealership SM that I are, and considering the 139,999 trouble-free miles that I've already driven, I replaced all the belt related, wear prone parts on the front of the engine -Water Pump, Idlers, Belts, Hoses, and Thermostat. Started the truck up after the repair, topped off the coolant (yes, with the Motorcraft orange stuff), and all seemed well... until I turned the A/C on. When the compressor is engaged there is a loud whine that follows the engine RPMs. Turn off the air or the defroster and it quits when the A/C compressor disengages. An added bonus is that the cooling fan at the radiator comes on at full high speed and doesn't stop until a minute or so after the compressor disengages, and just to further complicate the picture, after a few hours on the road, I can faintly smell cooking rubber when I walk past the front of the truck. So far, after about 500 miles, I have back-tracked the installation, checked pulley alignment, and checked for abnormal wear on the new belts, and nothing has jumped out at me. I know that the rubber smell tells me that something is definitely wrong, and I'm concerned about the radiator fan coming on when the A/C compressor is engaged because it's never felt the need to do that unless it's over 90 degrees outside. And of course the A/C whine... it really sounds like the clutch bearings have failed, but the whole picture has me perplexed, the noise , the smell, the fan behavior... have I missed something obvious? The truck has been dealer serviced every 5000 miles. Before I turned gray, I was an ASE certified Master Tech, so I'm no dummy under the hood, but this one is escaping me. Could it be that I'm a victim of multiple coincidental failures? Any opinions are welcome...

UncleG

I thought the radiator fan was supposed to come on when the compressor clutch engages.

Jen S

Did you ever find out what was causing your noise? We have a 2013 F150 5.0 with 131,000 trouble free miles....until we replaced the water pump. Same deal, no fanfare on the pump failure, just a little leak. Then after it was replaced we started getting noise that we would describe as happening under labor, such as going up a hill or switching gears. It would remind you of the rattle a catalytic converter makes when the honeycombs break loose. I can tell you that isn't the issue because they were replaced as it started throwing a code for it right after the pump was replaced. But the noise still persists. We've replaced injectors, belts, plugs and wires. We only use non ethanol fuel. Did you work yours out? We're pulling our hair out. We've had it since new and have always maintained it so this is a bit aggravating.

DASeneca

Hi Jen
As it turns out, my noise was definitely the A/C compressor, but there was still an irritating rattle at idle and low speed. When my transmission lead frame stuck (the only other repair I had to do in 198,000 miles, and it was warrantied!), the technician also noticed and repaired the front clamp on top of the converter. To my surprise, all the odd noises stopped! I had spent plenty of time under the truck before, and had never seen this clamp. I too, thought it was the converter coming undone. Rap the converter and exhaust system a few times with a rubber mallet and see if that doesn't duplicate the noise. Also, have you tried running premium fuel in it? It may be spark detonation. You could check the ignition timing to rule that out. The ECU system has a knock sensor, but it can fail without throwing an OBD code. Just a few thoughts... Good Luck!