Interesting intro ;-) Head gaskets don't fail too often on these engines, despite the iron block/aluminum head, although all bets are off on a high mileage turbo car such as Bruce's. If it were me, at that mileage I'd just pick up a used engine or take the opportunity to do a 1.8 swap. Your test sounds like a good one for the head gasket. It might be worth looking under a Miata hood to see that the water pump is not driven by the timing belt before condemning a stack of people... I have seen an impeller spin on the shaft only once in the past 30 years of wrench turning, on an Audi Fox. It's conceivable on a Miata, but not where I'd look first.
Bill Cardell TurboDog's Dad Flyin' Miata 1-800-359-6967 (sales) 970-464-5600 (tech support) www.flyinmiata.com www.fmwestfield.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of bill zimmerman Sent: Monday, April 11, 2011 9:07 PM To: 'Ross Kuhns'; 'Bruce Labitt' Cc: 'MiataPower' Subject: RE: Diagnosing Bad Water Pump, or Heater Core or? OK, you admit to getting it PFH (pretty effin hot) and now all it will do is overheat. Aluminum head, iron block, surefire recipe for head gasket failure, but all the dreamers want to put a pump on it and roll. Broken shaft in water pump? With the timing belt still running in place, be sure and get pictures of that. Try filling it with water when it's stone cold and put a pressure test on the cooling system (you can borrow a tester from AutoZone). Leave it under pressure for about 30 minutes and see if there is any drop in pressure, indicating a leak. No pressure drop, start it and try to warm it up, not cooking hot, but well off the cold side of the dial, and run a compression test while hot. I have seen overheated gaskets that would only start to leak as engine temps started to rise. If you do the timing belt, water pump deal without doing this and it still overheats, you will be very pissed at yourself for a long, long time. I haven't been on this list for a long time but I have pulled wrenches for a lot of my life and the more I read here, the more I am convinced that many of you should not be allowed to own wrenches. Best of luck and I really hope that the dream comes true and you don't have a head gasket problem. BZ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ross Kuhns Sent: Monday, April 11, 2011 10:25 PM To: Bruce Labitt Cc: MiataPower Subject: Re: Diagnosing Bad Water Pump, or Heater Core or? Well, if the pump shaft broke or something, I still think you should just pull the belt and see if it spins very freely, or grinds or does some damned 'wrong' thing. Didn't you have the timing belt done recently? did they do the water pump too? should be under warranty 'if' it is the pump... Ross On Apr 11, 2011, at 9:13 PM, Bruce Labitt wrote: > On 4/11/2011 9:00 PM, Donni wrote: >> Sounds water pump-y..... >> >> > > Grumble. So it would seem. Anything else I *should* be fixing while > I'm in there? > 1) water pump > 2) timing belt / seals > 3) ? > > Bruce > >> On Apr 11, 2011, at 7:33 PM, Bruce >> Labitt<[email protected]> wrote: >> >>> On 4/11/2011 7:05 PM, Larry Alster wrote: >>>> For the freeze plug to be your problem you would have to be losing fluid >>>> from the system. Are you?? >>>> >>> No, I have no visible leak. I am unaware of any leak. My first indication of trouble was an overheat this spring. I let it idle to warm up. While I was doing something else I noticed the rad cap geysering. I shut it down rather quickly. When it cooled down, I refilled the radiator. Fired it up again and it overheats. >>> >>> Tried running without the cap. Did not see evidence of obvious flow >>> in radiator. No obvious bubbles like a bad head gasket leak to coolant. >>> >>> Bruce >>>> >>>> Larry Alster >>>> >>>> 91 Miata White Knight >>>> 92 Miata Silver Bullet >>>> 92 Miata Honey B >>>> 04 MSM MX-5 Whooosh >>>> 06 WRX STi Subie >>>> >>>> >>>> -----Original Message----- >>>> From: [email protected] >>>> [mailto:[email protected]] On Behalf Of Bruce >>>> Labitt >>>> Sent: Monday, April 11, 2011 7:04 PM >>>> To: MiataPower >>>> Subject: Re: Diagnosing Bad Water Pump, or Heater Core or? >>>> >>>> On 4/11/2011 12:16 PM, Donni Howell wrote: >>>>> I may have missed it among all the replies, but I didn't see any >>>>> mention of core plugs (freeze plug/expansion plug or whatever you >>>>> choose to call them). I had a '96 that would overheat all the >>>>> time. I chased the problem for almost a year. Replaced radiator, >>>>> cap, had recently replaced water pump. Nothing worked and I had >>>>> given up. I lost some coolant but never found a leak. >>>>> >>>>> One day while doing some suspension work on the left side of the >>>>> car, I noticed a rusty streak on the side of the block - under the >>>>> exhaust manifold. I followed that up to a hole in the block where >>>>> a core plug used to live. It was a hidden leak that must have >>>>> burned off any trace of water while driving, so I never saw any >>>>> water on the ground. I replaced it with one from Mazda (2 from >>>>> NAPA wouldn't fit for some reason) and problem solved. >>>>> >>>> Nahh, did not even think about freeze plugs. Did you replace them >>>> with the engine in the car? >>>> >>>>> On Sun, Apr 10, 2011 at 9:58 PM, bill zimmerman >>>>> <[email protected]<mailto:[email protected]>> wrote: >>>>> >>>>> Now we're at the root of the problem, why did it >>>>> overheat, not because of >>>>> the heater core. It may have had a bad radiator, >>>>> leaking and you didn't >>>>> notice it, or it might be a bad water pump, also >>>>> leaking and you didn't >>>>> notice it, either way, low on coolant and overheating. >>>>> Very good chance you >>>>> have a warped head and leaking head gasket at this >>>>> point, check for water in >>>>> the oil, oil residue in the radiator, and do a >>>>> compression check. Go forward >>>>> from there, from the way you describe it I'm pretty >>>>> sure you are going to >>>>> find a head gasket problem. BZ >>>>> >>>>> -----Original Message----- >>>>> From: [email protected] >>>>> <mailto:[email protected]> >>>>> [mailto:[email protected] >>>>> <mailto:[email protected]>] On Behalf >>>>> Of Bruce Labitt >>>>> Sent: Sunday, April 10, 2011 7:59 PM >>>>> To: [email protected] >>>>> <mailto:[email protected]> >>>>> Subject: Re: Diagnosing Bad Water Pump, or Heater Core or? >>>>> >>>>> On 4/10/2011 7:42 PM, bill zimmerman wrote: >>>>> > Late coming in on this and have not read other posts >>>>> but if your problem >>>>> > came after any cooling system work, hose >>>>> replacement, etc, make sure you >>>>> > don't have an air lock in the system, which >>>>> frequently will result in no >>>>> > heat from the heater while everything else functions >>>>> normally. Would not >>>>> > suspect a water pump problem if the motor is not >>>>> overheating or signs of >>>>> > leakage around the pump. BZ >>>>> > >>>>> >>>>> Original problem - overheat - radiator cap let go - >>>>> coolant >>>>> everywhere. Replaced cap, added water - trouble ever >>>>> since. Engine overheats. >>>>> >>>>> Could be air lock. How do you get rid of it? I used a >>>>> coolant funnel attached to radiator cap. Attempted to >>>>> squeeze hoses... Car is not level right now. Front >>>>> end is >>>>> on jackstands. Problem? >>>>> >>>>> > -----Original Message----- >>>>> > From: [email protected] >>>>> <mailto:[email protected]> >>>>> > [mailto:[email protected] >>>>> <mailto:[email protected]>] On Behalf >>>>> Of Bruce Labitt >>>>> > Sent: Sunday, April 10, 2011 7:22 PM >>>>> > To: [email protected] >>>>> <mailto:[email protected]> >>>>> > Subject: Re: Diagnosing Bad Water Pump, or Heater >>>>> Core or? >>>>> > >>>>> > On 4/10/2011 5:25 PM, Ross Kuhns wrote: >>>>> >> If the hoses are only a year old, they should come off; >>>>> >> take a pair of slotted type pliers/grips and you can >>>>> >> usually work them back and forth a touch as you pull - >>>>> >> tool is set perpendicular to the pipe/hose. Of course >>>>> >> don't squeeze too hard, those pipes are soft. If >>>>> you try >>>>> >> to confirm flow thru the core, make sure not to use too >>>>> >> much psi, system doesn't run under too much >>>>> pressure (what >>>>> >> 13psi?). >>>>> >> >>>>> >> Ross >>>>> >> >>>>> >> >>>>> >> >>>>> >> On Apr 10, 2011, at 4:34 PM, Ken Bogart wrote: >>>>> >> >>>>> >>> I would flush the heater core to verify flow. If its >>>>> >>> blocked and needs replacement, a temporary bypass will >>>>> >>> certainly work to keep you on the road. >>>>> >>> >>>>> >>> >>>>> >>> Ken Bogart >>>>> >>> ----------------------------------------------------- >>>>> >>> 96 Montego Blue FFS Coldside (His) >>>>> >>> 97 Black& Tan (Hers) >>>>> >>> 90 Crystal White (sons) >>>>> >>> ------------------------------------------------------ >>>>> >>> http://www.miatacare.com<http://www.miatacare.com/> >>>>> >>> http://www.cincimiata.com<http://www.cincimiata.com/> >>>>> >>> >>>>> http://www.bcchallenger.org<http://www.bcchallenger.org/> >>>>> >>> MiataMail.com<http://MiataMail.com> list owner >>>>> >>> >>>>> >>> >>>>> >>> On Sun, Apr 10, 2011 at 2:32 PM, Bruce Labitt >>>>> >>> <[email protected] >>>>> <mailto:[email protected]> >>>>> >>> <mailto:[email protected] >>>>> <mailto:[email protected]>>> wrote: >>>>> >>> >>>>> >>> I'm trying to diagnose if I have either a bad >>>>> water >>>>> >>> pump, or just a clogged heater core. The >>>>> hose at the >>>>> >>> output of the heater core has been spliced to >>>>> insert >>>>> >>> a GM temperature sensor in the line. [Other >>>>> than the >>>>> >>> temp sensor splice, the cooling system is stock.] >>>>> >>> The GM sensor is reading correctly - it >>>>> reads cold >>>>> >>> and the heater line *is* cold. However, at >>>>> the back >>>>> >>> of the head, the sensor which goes to the >>>>> dash reads >>>>> >>> very hot (after the engine has warmed up, of >>>>> course). >>>>> >>> It is as if there is no flow out the back of >>>>> the head. >>>>> >>> >>>>> >>> Things I've tried: >>>>> >>> 0. Removed thermostat, put housing back. Still >>>>> >>> overheats. Have new tstat, but have not >>>>> installed. >>>>> >>> 1. Remove GM sensor splice, and inspect the >>>>> inline >>>>> >>> housing. Can see daylight through the hose >>>>> >>> connections. Conclusion: temp sensor housing >>>>> is not >>>>> >>> clogged and not impeding coolant flow. >>>>> >>> 2. Added classic coolant flush tee in place >>>>> of the >>>>> >>> inline temp sensor. Flushed 12 gallons thru >>>>> system. >>>>> >>> Pretty ugly looking coolant, if I must say >>>>> so. It >>>>> >>> still does not quite look like clean water, >>>>> but it is >>>>> >>> far more water like than before. >>>>> >>> 3. Put back GM temp sensor. >>>>> >>> 4. Refilled with water. Installed a burp >>>>> bucket on >>>>> >>> radiator, ran engine. Filled bucket 1/3 way. >>>>> Bottom >>>>> >>> rad hose does not seem like it is full of >>>>> coolant. >>>>> >>> Feels like it is not uniformly hot. Tried >>>>> squeezing >>>>> >>> hoses, etc to burp. Not much happened with >>>>> respect >>>>> >>> to coolant level. Engine heated up - back of head >>>>> >>> sensor showed quite warm - heater core loop quite >>>>> >>> cool to the touch. >>>>> >>> >>>>> >>> What I'm going to do next: >>>>> >>> 1. Bypass heater core. Is there an 'easy' >>>>> way to >>>>> >>> get these hoses off? I cut them when I >>>>> replaced them >>>>> >>> last summer. Are they 'welded' on by now? >>>>> >>> 2. Maybe, flush core, if above works. >>>>> >>> >>>>> >>> Anything else? >>>>> >>> >>>>> >>> _______________________________________________ >>>>> >>> Miatapower mailing list >>>>> >>> [email protected] >>>>> <mailto:[email protected]> >>>>> >>> <mailto:[email protected] >>>>> <mailto:[email protected]>> >>>>> >>> >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> >>> >>>>> >>> >>>>> >>> _______________________________________________ >>>>> >>> Miatapower mailing list >>>>> >>> [email protected] >>>>> <mailto:[email protected]><mailto:[email protected] >>>>> <mailto:[email protected]>> >>>>> >>> >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> > Well, I didn't quite do things in order. I flushed the >>>>> > heater core. (Pulled heater hoses, attached garden hose >>>>> > with anti-backflow to one side, attached 6 foot hose to >>>>> > bucket on the other side.) Nasty, but eventually >>>>> ran sort >>>>> > of clear. So it is NOT the heater core. Loads of >>>>> water ran >>>>> > through it - it does not appear to be a restriction. No >>>>> > water in the cabin, either - thank goodness. >>>>> > >>>>> > Then I back flushed the head. In the water neck in >>>>> the back >>>>> > of the head - out the other pipe to the heater core. >>>>> > >>>>> > Hooked everything up again. Filled through burping >>>>> funnel. >>>>> > No apparent flow through the core. However, the >>>>> thermostat >>>>> > is NOT installed. >>>>> > >>>>> > Is the thermostat required for the heater core to >>>>> get water >>>>> > flow? >>>>> > >>>>> > I have a standard new Stant thermostat. Do I need >>>>> to drill >>>>> > out the 'jiggler'? Hole size? Hole is up, correct? >>>>> > >>>>> > Is there a good test for a water pump? Looks like I'm >>>>> > running out of ideas. Carried off 50 gallons of >>>>> 'water'. >>>>> > What a fruitless day. >>>>> > >>>>> > Got insight? >>>>> > >>>>> > Thanks >>>>> > _______________________________________________ >>>>> > Miatapower mailing list >>>>> > [email protected] >>>>> <mailto:[email protected]> >>>>> > >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> > >>>>> > >>>>> >>>>> _______________________________________________ >>>>> Miatapower mailing list >>>>> [email protected] >>>>> <mailto:[email protected]> >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> >>>>> _______________________________________________ >>>>> Miatapower mailing list >>>>> [email protected] >>>>> <mailto:[email protected]> >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> "It is rightly acknowledged that people of faith have no monopoly >>>>> of virtue..." >>>>> -Queen Elizabeth II >>>>> >>>>> >>>>> _______________________________________________ >>>>> Miatapower mailing list >>>>> [email protected] >>>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>> _______________________________________________ >>>> Miatapower mailing list >>>> [email protected] >>>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >>>> >>>> >>>> >>> _______________________________________________ >>> Miatapower mailing list >>> [email protected] >>> http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower >> > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower > _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
