signs of a bad water pump

Discussion in 'The Big Chill' started by thapachuco, May 17, 2012.

  1. thapachuco

    thapachuco Well-Known Member

    my fan blades can free spin by hand easily when the car is off. Is this a blown water pump?

    The fan spins when the car is on. But my temp creeps up to 210 then i shut the car off, i thought it was the timing. There is a very slight rattle sound in the engine and it shakes more than normal. Bad pump?

    Can a blown water pump damage other parts? I got the car rebuilt in 2008. Put maybe 5000 miles on it, probably less.

    1967 with a 340 engine.

  2. SteeveeDee

    SteeveeDee Orange Acres

    I'm assuming you have a clutch-type fan. If it spins freely when the engine is off, the clutch is possibly bad. Is the car overheating? If not, the clutch is OK. Also, it is normal for the temp to go up after the car is shut off.
  3. DaWildcat

    DaWildcat Platinum Level Contributor

    Like Steve said, your car has a thermostatic clutch connecting the fan to the water pump. When the clutch is exposed to hot air, it engages (not completely mind you, there's no true "lock up"), causing the fan to turn as the pump turns. When cold, the clutch is disengaged, so the fan can freewheel even though the pump is turning. The amount of engagement the clutch provides depends on the engine's operating temperature at the time, determined by the temp of the air coming through the radiator.

    With the engine off and hot after a drive, you should still be able to turn the fan by hand but you should feel considerable resistance, and it should not "freewheel". If it does, the clutch is no longer functioning correctly.

  4. Briz

    Briz Platinum Level Contributor

    And to add to the above, If you have a fixed blade fan and its free wheeling you have more serious problems than a water pump.:eek2: Really though, if your water pump was bad you would know. It would either leak from the weap hole or the berrings would have come out of the front. as long as its spining its moving water.
  5. thapachuco

    thapachuco Well-Known Member

    crap, well...

    from what i remember before my rebuild the fan never used to move. It took a lot of strength to turn the fan by hand.

    There is a small rattling noise and i thought it was possible the bearing in the water pump. There is no leaking.

    Another thing i noticed was that the lower radiator hose was hot, the upper was not, the back heater hose was not hot from engine but the one leading into the pump was hot.

    maybe i just have a bad thermostat...since 5 de mayo, i noticed the temp going past 190 and it never used to do that. always stayed at 180

    what options do i have to trouble shoot here?

    thanks guys!

    ---------- Post added at 08:59 AM ---------- Previous post was at 08:57 AM ----------

    what more serious problems? Like the timing chain?

    I put the timing light on my car last night and the line on the harmonic balancer was on the other side of the engine, no where near the tab with the degree marks. This was both noted with the mechanical advance plugged/removed and hooked up to the distributor.

    ---------- Post added at 09:01 AM ---------- Previous post was at 08:59 AM ----------

    if i sit in traffic or am on the street driving around, the temp creeps up. I already know the signs of overheating, been there one too many times. so i turn it off before it gets too hot. But it's a steady rise.

    ---------- Post added at 09:09 AM ---------- Previous post was at 09:01 AM ----------

    one more thing. The engine shakes more than slightly. I attempted to give the carb a tune up since i had'nt in a while.

    My vacuum gauge was jumping around 15, i was never able to get it to the 20(apporved) mark on the gauge.

    Is there a standard vacuum pressure that is supposed to be maintained in the 340?
  6. thapachuco

    thapachuco Well-Known Member

    update: Got a new thermostat in the car. Fired it up and once it hit operating temp where the thermostat is supposed to open, the temp shot up to 210*

    what the hell!?!?

    the radiator was completely cold and it actually began to over flow. I left the cap off to burp the system and i just began to puke.

    any tips, getting desperate here... Going to try and replace the water pump tomorrow.

    what is the bolt order and are there any torque specs?

  7. SteeveeDee

    SteeveeDee Orange Acres

    Slow down, cowboy! Don't go throwing parts at it until it's fixed. That's just a wallet flattener .You probably have air in the system after the t-stat replacement. After it cools off, check it again, and add as necessary. Leave the cap off and run it until it looks like it's gonna burp, and shut it off. Wait for it to cool, and check again.

    Note: some guys drill a couple of small (~1/16") holes in the thermostat to allow it to bleed out the air while changing coolant.
  8. thapachuco

    thapachuco Well-Known Member

    What are your thoughts about the hose temps and the radiator being completely cold all the while my temp gauge reading 210*?

    i'll try burping it again.
  9. thapachuco

    thapachuco Well-Known Member

    Final Update.

    Took my car down to a local radiator shop. The coolant was a brown color, def not the standard bright green coolant color. Luckily, it wasn't a blown head gasket. My aftermarket radiator has begun to wear and dissolve. It's aluminum. Apparetnly this is what theyre known for. Now i need to find a OEM buick radiator with 4 cores.
  10. DaWildcat

    DaWildcat Platinum Level Contributor

    Huh???? The only way that can happen is if you let it; i.e. leaving tired or dead antifreeze in the system or running water with no anti-corrosion additive. That's also the negligence that kills front covers, water pumps and thermostat housings.

    I've had my Howe aluminum radiator in place for over fifteen years and it looks as good on the inside as it did when it was new!

  11. thapachuco

    thapachuco Well-Known Member

    well, after my rebuild about 5 years ago. From what i remember i hadn't changed the coolant the whole time.

    Maybe after this flush, if i stay more aware of the coolant then i shouldnt happen again?

    There we're hot and cold spots on the radiator before the flush, is that indicative of a blocked core?

    how ofter should i flush / change the coolant?

    so fat its been steady at 180*
  12. DaWildcat

    DaWildcat Platinum Level Contributor

    I have trouble reading your writing. "so fat"?

    Five years without checking the coolant, no surprise that you may be having issues with corrosion. Do you know how to check the coolant? If so, we'll go from there.

  13. thapachuco

    thapachuco Well-Known Member

    Sorry dude, was typing in a rush.

    Yea, i think it has been that long. Stupid mistake on my end.

    Please school me as to how i can regularly test the coolant.

    So FAR it's been running at 180* no more spikes to 210* +
  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Test it? Change it every 2 years, and you will stay out of trouble. The only reason to test it is to check freeze protection. A 50/50 mix should be good to -34* if I remember correctly. Anti freeze doesn't transfer heat as well as water, so never use concentrations above 70%. In fact, if you don't need freeze protection because of where you live, you can use less anti freeze, more water, and a bottle of Red Line water wetter, or similar additive. The engine will run cooler with less anti freeze.
  15. DaWildcat

    DaWildcat Platinum Level Contributor

    Horsehockey. Yes, TEST IT. Not just for freeze point, but for electrolysis. Don't worry, the electrolysis test isn't rocket science and has been around forever! It should be in every wizard's book of tricks.

  16. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes sir!:laugh: You are absolutely correct of course. I'm going to test mine today. BTW, I think the Pachuco was way past this. What is a pachuco anyway?
  17. DaWildcat

    DaWildcat Platinum Level Contributor

    What's funnier is that I was thinking the same thing; I haven't tested mine since last fall. Now I have to remember which neighbor borrowed my multimeter last week. :laugh:

  18. Smartin

    Smartin Staff Member

  19. thapachuco

    thapachuco Well-Known Member

    Interesting. I usually run the 50/50 mix. Im more concerned about the engine rusting out and or mixing with the aluminum particles in the radiator. But assuming i flush the system every two years, I suppose i'll be ok.

    ---------- Post added at 03:14 PM ---------- Previous post was at 03:14 PM ----------

    Im definitely going to try this.

    ---------- Post added at 03:15 PM ---------- Previous post was at 03:14 PM ----------

    Haha, dig on the wikipedia definition posted by Smartin

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