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1989 Firebird...overheating?

kkollwitzkkollwitz Posts: 274
edited March 2014 in Pontiac
after some congested in-town driving (temp below 220), I could not start the car after turning it off for a couple of minutes. Turning the key would not engage the starter, but would start the electric fan, which would run as long as I kept the key turned. I raised the hood, waited five minutes or so, tried again, started normally. In 12 1/2 years, I've never had this happen before. What's the story?


  • andre1969andre1969 Posts: 24,476
    Is your car still on its original starter? If so, the starter may be beginning to go bad. Sometimes, they'll get, for lack of a better word, "bad spots" on them. Sometimes they'll start, sometimes they'll grind, sometimes they'll do nothing.

    When the car finally started, what was the temperature gauge reading? If the car was really overheated, 5 minutes wouldn't have been enough to cool it down. It could be that something, like a problem with the exhaust, is causing the starter to get hot. I have this problem with my '67 Catalina. On hot days, it'll start fine the first time. But if it's been running awhile and I turn it off, when I go to turn it back on, it'll just make a grumble, and then nothing. But then if I turn the key again, it fires right up.
  • it's the original starter...so maybe the fan always starts with the starter if it's hot enough, but I never could tell because it's so much quieter than the engine turning over. The temp when I turned the car off was around 210, very typical, although it was unusually humid today, which may've affected the starter.
  • you have a heat soak problem. Might want to check all the conections at the Battery and the starter for corrosion or frayed wires. Make sure the the starters heat shield is in place.

    When hot, these starters need a lot of juice to get them turning. The starter is probably okay but that solenoid (on the side of the GM starter) could be on the way out.
  • Thanks, I'll check....what exactly is a "heat soak problem"?
  • andre1969andre1969 Posts: 24,476
    ...now that I think back on it, my old '69 Bonneville used to eat solenoids on a regular basis. The starter would be fine, but the solenoid would just burn up.

    As for "heat soak", isn't that when you turn your car off, and the heat from the engine dissipates from the engine block, heating up external things in the engine bay? Once the car isn't moving and the fan is off, there's nothing to blow off that heat, so it just slowly radiates from the engine, heating everything up.
  • specifically, in our posters case, extreme heating of the starter/solenoid.
    Due to the starters location on the GM 305/350 engines, the solenoid is exposed to extreme engine temperature. This causes a reduction in current and an increase in resistance through the unit and weakens the magnetic field. This usually happens after driving around a hot summer day, shutting the engine off and then try to start the car after 20 or so minutes. Allowing the car to cool off will usually do the trick and she will start again.

    Now sometimes installing a new battery with the highest CCA you can fit and get, will give you a temporary fix. (CCA= COLD Cranking Amps) Like I said earlier, those puppies (Starters) need a lot of amps to get'em moving when they are hot.

    A Remote solenoid kit can also fix the problem. Most parts stores sell them. It removes the solenoid function at the starter and replaces it with a "remote" one that you mount up higher in the engine bay. This eliminates the possibilty of direct engine heat impeeding the soleniods efficency.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    Yep, could be a bad spot on the armature of the starter. But of course, check all connections going to the starter first, beginning with your battery (as stated, starters need LOTS of amperage to crank) and working down to the starter motor connections.
  • I've had an '89 Firebird since it was new and have ALWAYS had problems with it running hot, or at least what I believe to be hot. It's the 305 cid throttle body engine and as long as I'm moving with the A/C running, the temp. runs around 175. If I sit still for very long (a few minutes) you can watch the temp. guage go up. If it idles for ten minutes or more, it boils over, guaranteed!
    I'm not sure if there's a device that kicks the cooling fan on at a certain temp., but if so it doesn't seem to kick on until about 220 degrees. I've thought about just wiring the fan to run all the time, but usually just keep the a/c on which keeps the fan on.
    Anyway, anybody else having the same problem??? Any ideas that might fix it??? Are all Firebirds stricken with this disease??? Thanks.
  • 0patience0patience Oregon CoastPosts: 1,712
    Here are some common causes of overheating on newer vehicles, especially ones with electric fans.

    Insufficient coolant mix.
    Bad radiator cap.
    Stuck thermostat.
    One or both fans not operating properly.
    And on some vehicles, there is a high and low fan operation, sometimes the high doesn't work properly.

    The first 2 should be the first checks.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaPosts: 64,482
    Yes, a bad radiator cap means you have no pressure on the coolant. Pressure raises the boiling point.
  • hjw1hjw1 Posts: 17
    We bought a 1988 Firebird new and put 120,000 miles on it. We currently own a 1992 Firebird purchased new that has 74,000 miles on it. Both with 305 engines. Both excellent cars.

    However, I've always been uncomfortable with the fact that the electric fan (when not operating the A/C) doesn't come on till something like 220-230 degrees F. With a 50/50 mixture of coolant and a properly operating radiator cap, we've never boiled out coolant, but the car does have a propensity to ping a little under these circumstances.

    The only time we came close to overheating was after a major storm in 1998. We had significant rainfall and hail that tore leaves from the trees that plugged storm sewers. Intersections were flooded between my workplace and our home. Against my better judgement, I drove the 1992 Firebird though some awfully deep water that was full of leaves and elm seeds. Over the next few days after the storm, I noticed that the Firebird was running warmer than usual. What happened was that leaves and elm seeds got packed between the A/C condenser coil and the radiator. When I cleaned out the debris the problem was solved.
  • Sitting still in traffic or idling will cause coolent temps to rise. They suck air from under the nose. That is why it is important the birds air deflector is not missing or damaged. Of course this is not what is causing your over-heating problem.
    There are cooling mods you can try. One of the best is to have both fans kick on at a lower temp. Several F-body sites have sections devoted on this "How To" modification.
    Another is to replace the rad core or side tanks with larger capicity ones. It is 12 years old and is probably running less than 100% in the cooling department.

    But, all in all, getting those fans on sooner will make a big difference.
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