Page 2 of 2 FirstFirst 12
Results 21 to 31 of 31

Thread: Heater core no coolant circulation, but not plugged

  1. #21
    Administrator llamavan's Avatar
    My Van(s):
    1985 5-sp cargo (Trustyvan) . . . . 1989 5-sp 4WD DLX (Skylervan)
    Join Date
    Jun 2010
    Location
    PNW
    Posts
    1,773
    Rep Power
    10

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Well, look at it this way ... what's the cost of aftermarket headgasket PLUS OEM headgasket PLUS doing the job twice?

    Just go OEM. It will save you waaaaay more money than you're fussing over right now.

    Gwen
    1985 5-speed window cargo van set up for llama haulin'; 345K ("Trustyvan")
    1989 4WD 5-speed DLX; 410K and an odd sense of humor ("Skylervan")

  2. #22
    Van Enthusiast
    My Van(s):
    87 4x4
    Join Date
    Jan 2012
    Location
    Reno, NV
    Posts
    264
    Rep Power
    1

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    My felpro failed after 2 years.

  3. #23
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,095
    Rep Power
    10

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Quote Originally Posted by llamavan View Post
    Well, look at it this way ... what's the cost of aftermarket headgasket PLUS OEM headgasket PLUS doing the job twice?

    Just go OEM. It will save you waaaaay more money than you're fussing over right now.

    Gwen

  4. #24
    Van Fan Filippo's Avatar
    My Van(s):
    1989 Toyota Van Crg 2WD
    Join Date
    May 2015
    Location
    North Augusta, South Carolina, USA
    Posts
    24
    Rep Power
    1

    Smile Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Update: it wasnt the head gasket. I tested it and no products of combustion in my coolant. I borrowed a pressure tester and found a pin hole in the hose from the heater core. As the engine heated it moved coolant into the resevoir, as it cooled it drew air in from the hole instead of coolant from the resevoir. Air pockets gathered in the core and didnt allow proper circulation. Problem solved....i hope. The head gaskets must be tough to not habe failed under these conditions.

  5. #25
    Forum Newbie
    My Van(s):
    1986 LE 2 wd 1988 4x4
    Join Date
    Apr 2016
    Location
    Del Norte, Colorado
    Posts
    10
    Rep Power
    1

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Quote Originally Posted by Filippo View Post
    I am having the same issue. Van runs fine for awhile then the heater in the front stops blowing hot and the van overheats. I have replaced the water pump, new belt with correct tension, replaced and later removed the thermostat. Disconnected rear heating route, checked the flow valve in the heater hoses, flushed the engine and hoses and heater core, replaced the radiator, replaced the fan clutch, and added a 2nd aftermarket fan. I removed the air conditioning fan and condenser to allow more air flow to the engine. I dont see any external leaks. I ordered a block leak tester to check the head gasket but i dont see oil in the water or any white smoke. Im running out of ideas of what it could possibly be. Any ideas or suggestions?
    Okay now, 2 things.
    How does the radiator look on the outside front? If the face is blocked by those fluffy balls from cottonwood trees you'ld never see it, happened to me so I blew high pressure air through to clear it. Simple stuff but ya have to look.
    But if there's a clue after it's after "awhile", Meaning obvious it's blowing or leaking or burning out the coolant lowering the fluid level to the point the heater core goes dry, thus no heat inside and then the engine gets hot.

    I just want to see someone pull the heater core. I had a mouse plug the plenum up with carpet fiber and I'll be danged if I can figure out how to get it cleared without pulling the entire dash apart again.

  6. #26
    Van Fan Filippo's Avatar
    My Van(s):
    1989 Toyota Van Crg 2WD
    Join Date
    May 2015
    Location
    North Augusta, South Carolina, USA
    Posts
    24
    Rep Power
    1

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Even though i had no signs of head gasket leakage, i finally went ahead and changed it out. That was the problem. Hot gases from combustion were crossing into the coolant, super heating and pressurizing it. It forced the coolant into the reservoir and eventually the level would drop low enough to not have an adequate amount to reach the heater core

  7. #27
    Van Enthusiast
    My Van(s):
    1990 Hiace Super Custom 4WD diesel
    Join Date
    Sep 2016
    Location
    SoCal
    Posts
    233
    Rep Power
    1

    Re: Heater core no coolant circulation, but not plugged...water pump dying?

    Quote Originally Posted by NWVanner View Post
    Wondering if the rear heater has anything to do with it. Does it work?
    I recently replaced the thermostat and flushed the system but still didn't have good rear heat.
    Tapping on the metal line around the flow switch, 1 sprung a leak.
    I had to cut the rotted corner off. There was a lot of debris trapped in that low corner that wasn't touched in the flush. I re flushed from the back and fixed the tube.
    Good heat in the rear and stays 181* all day.



    If there was any oil in that frothy green coolant, it would be an obvious head gasket. The color is indicative of an issue.

    I use the Toyota red coolant in all my Toyotas.
    Ill never felpro HG again! Anywhere else I would.

  8. #28
    Van Fan
    My Van(s):
    85 TV 2wd M/T 87 4x4 LE A/T
    Join Date
    Jul 2013
    Location
    seattle
    Posts
    92
    Rep Power
    1

    Temp gauge redline... air blowing cool

    Hey guys<br><br>just left the house 1 mile drive and my temp gauge is almost at the ceiling! I turn the air to maximum heat and it was coming into the cab cool.. which I've never experienced. Is this a thermostat symptom?<br><br>thanks for any advice

    i was 24oz low on cooolant. Things seem to be good now anyone know how to delete this post?
    Last edited by ingmire; 07-20-2018 at 11:34 PM.

  9. #29
    Van Fan Grappler's Avatar
    My Van(s):
    1987 Cargo: 'LOLVAN'
    Join Date
    Feb 2017
    Location
    Los Angeles
    Posts
    26
    Rep Power
    1

    Re: Temp gauge redline... air blowing cool

    First thing I'd check once everything's not hot is your coolant level, not just in the overflow tank but under the actual pressure cap. A lot of times, this symptom is indicative of air or exhaust gas circulating instead of coolant.

    Once you ensure it's all the way filled up, you can more easily determine if it's a leaky hose (see: hose of death threads) a radiator leak, or exhaust gas seeping into the system from a gasket break and expelling the coolant (that would be apparent if there's bubbles in your overflow tank after running)

    Note: I realize this sounds like potential doomsaying, but I will say the first time this happened to me it was a bad radiator cap, so it can just as easily be something simple!

  10. #30
    Van Enthusiast bushcat's Avatar
    My Van(s):
    '85 Toyota 2WD Cargo Van 5 Speed ------------------ '89 Toyota 4WD LE Auto
    Join Date
    Dec 2017
    Location
    Benicia, CA
    Posts
    110
    Rep Power
    1

    Re: Heater core no coolant circulation, but not plugged

    If the rear heater core is clogged, could that affect heat in the front? I removed the controls for the back and I've flushed the front heater core and I still get pretty weak heat. I know they are weak in general but mine seems especially weak. It's warm but if I was in snowy conditions, I'm not sure it would defrost in an hour.

  11. #31
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,095
    Rep Power
    10

    Re: Heater core no coolant circulation, but not plugged

    Rear being clogged wouldn't effect the front unless the clog was in the common return line (unlikely). If your heater is not blowing hot, the 1st thing to check is the coolant temperature. It should be ~180 F or so. If the coolant isn't getting hot then the heater won't get hot either. If that's the case then replace the engine T-stat. If the coolant is hot, then get under the front of the van to make sure the cable controlled heater hose valve is open. If it is, then check the duct doors to make sure they're opening/closing correctly. If all that checks out then the next most likely issue is a clogged heater core. Tim

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •