I have the non-thermostatic-coil clutch on my fan. I tuned the engine up the other day, and this afternoon it seemed like way too low of an idle. Threw the dwell tach on it and it was at 600 rpm Then I used the timing light and it was at least 16* advance initial, maybe closer to 18, I don't know, it was well off the scale...what the??? Thought maybe that the advance weights were stuck...no dice, but I did notice that a module wire for my HEI was loose. Took care of that and tuned it again, all was well, but... When I revved it to about 1200 rpm a few times, the last time, the engine made a zinging type of noise from the front....thoughts of spun bearing chilled my spine for a second. I shut the engine off and walked back to the front of the car, and I noticed the fan was spinning rapidly, and took maybe 30 seconds to stop. Now, I've had the engine since '92 and I don't recall that ever happening before. I went inside to get a glass of water, and came back out. I spun the fan by hand, it went around maybe a dozen times!ou: I started it back up to check the coolant temp while the engine was running. It was dead on t-stat temp. I shut it off again, and the fan stopped in maybe 5 seconds:shock: I spun it by hand, and it rotated once. Started it a third time and the zinging noise went away when I revved it....but when I shut it off and immediately started it up again, the noise was back. Now, this has got to be the clutch, right? Right, but I've never had one that worked and then didn't work, and I never had a bad one (I've had three let go) that didn't make the car overheat in traffic...well, I'm not overheating in traffic and this one really seems bad. I'm replacing it, gonna use the old cardboard in front of the radiator trick, but this is a screwy thing, to my mind. Anyone else have a fan clutch act like this? I see zero evidence of leakage on the clutch, by the way.
Chris, Sounds like the fan clutch is on it's way out. If you spin the fan by hand, it should go maybe one revolution and stop. I have the NAPA 271301 and it won't even go 1/3 of a revolution.
That clutch is wiped out. I had the same problem on a Trans Am I had. Also check for small amounts of oil on the clutch.
