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Discussion Starter · #1 ·
As most of you may already know from my post questioning the monovalve, I have a problem with intermittant heat. I am wondering which direction the coolant is supposed to flow through the monovalve, is it bottom to top? Has anyone ever seen a plugged heater core allow coolant flow intermittantly?
 

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why don't you take the monovalve out of your parts car and try it . not sure which way up/down the coolant flows. seems to me a blocked heater core is pretty rare in these cars but maybe not impossible. i would assume you would get leakage in the cabin and then you would know for sure the heater core is shot.

thought you were going on a long drive tonite....

[:D]
 

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Discussion Starter · #3 ·
I bypassed my monovalve this afternoon and removed the valves from both cars. I then blew through each valve while connecting 12V jumpers to them, both tested good. I drove the car about 150 miles round trip tonight, on a first date by the way, with very little heat on the way to my destination and some heat on the way home. A blocked heater core is common in any car, especially a car that has the ability to shut off flow through the core, but a blocked core doesn't necessarily leak. I am going to flush my system this afternoon, something I should have done a long time ago, if this doesn't take care of the problem I am taking out full coverage on the car and parking on the railroad tracks. Ok, so I couldn't do that to the car but I will be pretty frustrated.
 

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sorry for your debacle.. yikes.. hope you get a second date!!
will be interested to hear the result after you flush the cooling system.
this kind of stuff isn't good anytime but it really bites in the winter...
 

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Discussion Starter · #5 ·
Turbo, the date went well aside from the lack of warmth. The heat in the car, on the other hand has been getting better and better since Saturday. It seems that the long driving and extra flow with bypassed aux pump and monovalve has opened up the heater core a bit. It's still not 100% but the car is, at least, comfortable within a short period of time. I have been pretty busy the last few days between work, school, and spending time with that girl so I have not had time to flush the system, I'm 100% positive, however that a good flush will take care of the problem, after which, I will reinstall monovalve and maybe even the aux pump if I can work it in around that circulation tank heater. Thanks again for all your help, I truely appreciate it.
 

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Stevenpfaff - 2/1/2005 3:39 AM

Turbo, the date went well aside from the lack of warmth. The heat in the car, on the other hand has been getting better and better since Saturday. It seems that the long driving and extra flow with bypassed aux pump and monovalve has opened up the heater core a bit. It's still not 100% but the car is, at least, comfortable within a short period of time. I have been pretty busy the last few days between work, school, and spending time with that girl so I have not had time to flush the system, I'm 100% positive, however that a good flush will take care of the problem, after which, I will reinstall monovalve and maybe even the aux pump if I can work it in around that circulation tank heater. Thanks again for all your help, I truely appreciate it.
no problem , we're all here to learn from each other.

maybe it got an air pocket in it and needed 'burping'
anycase flushing is always good - maybe it needs a citric acid flush/cleaning.
 

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Flow through the monovalve is from the side port to the bottom port.

Pop the top on the valve and check the diaphrams. Mine was working mechanically (opening and closing by solenoid), but there was a tear in the rubber I couldn't see without VERY close inspection that was allowing coolant to fill the core. Mine would cool off at high engine rpm.

Got a rebuild kit and so far it's been working well.
 

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Discussion Starter · #8 ·
My problem was caused by a partially clogged heater core. It seems to me that the coolant would sometimes be able to flow through if the engine was run at high rpm's for a long enough period of time but the clog would get caught again on it's way through. Anyway, it's working fine now, thanks for all your input!
 

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Aww...the fun is over![:(][:D]

Well, enjoy your new warm ride now!

EDIT: Oops, you haven't fixed it yet, have you? Best of luck on the heater core then [;)] Good to know you found the culprit
 

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Discussion Starter · #10 ·
Well, I haven't flushed my system yet, but the heat is working at full capacity now. I will eventually get around to doing a full flush and fill, but since I have good heat, I am concentrating on more important things; for example, the girl that braved that cold ride with me, and my upcoming geography test. Among other things, I just recently picked up a 1984 Honda VFR 500 interceptor for $170. The seller couldn't figure out why he didn't have any electrical power; I put some acid in the DRY battery, sprayed some starting fluid in the carbs, and took it for a ride. I do need to pull the carbs off and have them cleaned, adjust the valves and cam chains, and change the oil so It's ready to sell next month, so that will consume a good deal of my time. That should score me a quick $500 profit though!
 
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