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Monday, September 22, 2014

Engine Running Hot

I know, most of you are thinking thermostat, I replaced that twice. I figured out that the electric cooling motor wasn't coming on. I finally took it to the shop and they thought that it was the radiator cap going bad and not reading the correct pressure for the fan to kick on. They put a new cap on and for awhile (about a week) it seemed to work fine, now the engine is running hot again and the fan is not kicking in again, Anyone know anything else I can try before I put it back in the shop? BTW it is a 86 Chevrolet Camaro with a 2.8 v6. Thanks in advance


  1. is the coolant level low?

  2. Is there an electric sensor on your radiator cap?

    I never heard of a radiator cap preventing an electric radiator
    cooling fan from turning on.

    You could hotwire the fan to a switch, or better yet, find an
    electrical circuit you could add it to that's only on when the car is
    running to test whether it's the sensor/switch that turns on the fan
    or not. If all goes well, it's probably a thermal sensor somewhere
    that's not turning on the fan.

    This assumes that you aren't losing coolant or low on coolant for some
    reason, as was just mentioned.

  3. have you tried to flush the system out and replace antifreeze yet. it may be necessary. How many miles on it?...

  4. If the cooling system is low on water it can’t turn the fan on because the sensor is activated by the hot water. Most cars if you turn the A/C on it forces the fans to run.

    See if there’s water in the oil, and take the cap off the radiator and look for bubbles while the engine is running. .

  5. My number one rule is do not start replacing things until you find out what’s wrong with.

  6. Sometimes replacing something is a process of elimination...

  7. That's one way of fixing something, but it can be expensive at times.

    A better way is to eliminate what you can through testing and simple
    logic, then, when all else fails, replace the most likely culprit.

    Most items can be tested to determine if they are working properly or
    not. Some cannot, and even factory shop manuals will sometimes, after
    you have done a series of tests and ruled out some potential problems,
    have you replace item X with a known good item X.

    It's a shame that modern cars have got to the point where sometimes
    substitution is the only way to determine if something is bad or not.

    On the other hand, modern cars do have many things going for them, and
    they even run self-tests on many things for us and point us in the
    right direction, if not specifically to the exact problem, by using
    these tests.

    You can get a great OBD II tester for under $25 that works with any
    Android device, and it's more specific than my $125 Equus tester! Of
    course an OBD II code checker won't help you fix everything, and the
    whole system was set up around the newer emissions systems, so
    something like an intermittent light in the dash won't show up in the
    testing results.

  8. there is plenty of coolant in the radiator, and no oil in there either, doesn't seem to be a blown head gasket.

  9. No there is no sencor on the cap.

  10. yes I did flush the radiator but it was last summer.

  11. O yes, it has 183,000 miles on it