Just replaced the engine in daughter in laws 2001 3.4 Aztec. Radiator fans running when A/C on and gauge reads normal. Shut the air off and it runs hot,gauge very close to red line before fans run. Why do the fans come on so late and only run a short time? What can I do to make the fans run sooner?
why was the engine replaced? was this a symptom prior to engine replacement ? about how many miles are on the new engine?
Original engine needed head gaskets and had a bottom end knock. The bone yard engine has 85,000 miles on it and runs smooth as silk. I have no idea if the first engine ran hot or not. All is ok until sitting at 1 or 2 long stop lights with the air shut off then the gauge goes up close to the overheat red line.
I think that the fan on those is controlled by the engine management computer. If so, there is nothing you can easily do to kick it in sooner.
Do check the oil for signs of anti-freeze contamination. The intake manifold gaskets on that series of engines fails with alarming regularity. The most sensitive easy way to check is with a $25 used oil analysis at your next oil change interval.
John
"justme" wrote in news:xKadnbzMA_2M4kfZnZ2dnUVZ snipped-for-privacy@comcast.com:
Is there some sort of coolant sensor that needs replacing perhaps? Or an electronic module of sorts that triggers the fans? I'd get a Chilton's or Haynes at Autozone and trace it out.
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