Heater core plugged - 1998 Toyota Tacoma

Maybe the heater core is plugged or you haven't bled it properly?
If the heater hose returning from the core to the water pump is NOT hot, while the hose going to the heater core from the thermostat area IS hot, then the heater core is plugged probably.
You need to remove the heater hose while cool,from the thermostat area and remove the hose from the water pump area (that's the outlet of the flow thru heater core) AND THEN take a garden hose with p-is-tol grip type sprayer,and blow water back thru the outlet hose out the inlet hose. This will blow any bad plugging material out the way it got in.
Don't apply too much pressure if it is plugged bad. The heater core isn't made to stand 50lbs. water pressure. don-ohio (:^)

Possible plugged heater core. Check heater hoses when engine at operating temperature. Both hoses should be close to the same temperature. If one hot and one warm/cold, suspect a plugged heater core. A backflush will be required to correct the problem if it is plugged

Hi Carlos, Im AL the owner of Big As Auto Repair.

Carlos, several things can cause no heat through the vents. Starting with the one that's mostly found. (1) Heater Core Plugged up. You see, when the heater core is restricted and the hot water is not flowing through the entire core it has little or no heat. (2) Thermostat stuck open. This can cause you to have very little heat because the water is not getting to operating temperature. (3) Low on coolant. If the water in the radiator get's low enough it also can cause little heat when sitting at an idle and get hotter while driving down the road. (4) Heater door not working properly. This is the lest likely but does happen. FIRST thing to check, "coolant level". SECOND thing to check, "coolant flow through the radiator" THIRD thing to check, "heater core plugged". Here's how to check the heater core. Drive your vehicle until its at operating temperature. Then grab one of the heater hoses going into the heater core under the hood. NOW grab the other heater hose coming out of the heater core. NOTE: If you can keep holding one, BUT must let go of the other one because its to hot to hold, then your heater core is plugged. You can try to flush the heater core but sometimes it doesn't help. But, lets try this first before replacing it. Take the heater hoses off the engine side NOT off the heater core itself. Plug one of the hoses up with something to keep the cleaner in the heater core, THEN, find a way to empty the core best done with shop air, then pour a radiator cleaner into the other hose until its full to the top, then plug it with something to keep the cleaner in the heater core. NOTE let it set over night then take the plugs out and flush out in both direction until the water coming out is clean. Sometimes this doesn't works, but its worth a try. Sometimes this cleans the heater core out and it starts leaking but, its worth a try. Carlos, hope this helps and please visit my auto-repair-website at: http://www.bigasautorepair.com/

The heater core may be plugged with rusty mud. The blend door may not be moving to heat position. You can tell if the heater core is plugged by putting your hand on both heater hoses near the firewall after the engine is up to temperature and the heater controls are on and temperature is at 80 degrees. Both hoses should feel the same temperature. If one is way cooler than the other, your heater core is either plugged or the control valve is not letting water into the heater.

Can be a heater core issue:--

Regarding this types of problem,i suggest you to go through this help links.Click the link below to go through the procedure and troubleshoot the problem :----HOW TO REPLACE AN UPPER RADIATOR HOSE

http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-upper-radiator-hose.html

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HOW TO REPLACE A LOWER RADIATOR HOSEhttp://schematicsdiagram.blogspot.com/2011/07/how-to-replace-lower-radiator-hose.html
----------How to Flush Heater Core?http://schematicsdiagram.blogspot.com/2011/12/how-to-flush-heater-core.html
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For heater core replacing procedure. I suggest you to go through this related help links.Its all complete step by step procedure: ----How to replace heater core for All car models?

Click the link below: ---

http://technoanswers.blogspot.com/2011/11/how-to-replace-heater-core-for-all-car.html

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How to Flush Heater Core?

http://schematicsdiagram.blogspot.com/2011/12/how-to-flush-heater-core.html

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How to Remove Heater Core ?

http://howtobyme.blogspot.com/2011/12/how-to-remove-heater-core-on-2008-honda.html
Heater Core Replacement?

http://howtobyme.blogspot.com/2011/12/honda-heater-core-replacement.html

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To replace heater core?http://technoanswers.blogspot.in/2012/02/how-to-replace-heater-core-on.html------

How to replace heater core?http://technoanswers.blogspot.in/2012/02/how-to-replace-heater-core-on_10.html
How to replace heater core on Buick Regal?

http://howtobyme.blogspot.in/2012/02/how-to-replace-heater-core-on-buick.html
----------This will help.Thanks.

OK START WITH COLD CAR FIND HEATER HOSES (CENTER REAR OF ENG BAY) PINCH OFF HEATER HOSES WITH NIDDLE NOSE VICE GRIPS, REMOVE HEATER HOSE'S FROM HEATER CORE TUBES ( BOTH HOSES) INSTALL WATER HOSE TO ONE SIDE OF HEATER CORE , TURN WATTER ON AND LET IT FLOW 1 MIN. SHOULD DOO THE JOB, IF NOT YOU HAVE OTHER ISSUES.OH REASIMBLE EVERY THING BACK AS IT WAS BEFORE YOU STARTED, TAKE CARE WHEN REMOVING HEATER HOSES FROM HEATER CORE MAY BREAK HEATER CORE IF YOU ARE TOO RUFF,.......

Check that the heater core is not plugged by feeling the 2 heater hoses going into the firewall. If they both get hot, then the heater core is not at fault.

If they are cool, then the heater core is plugged then the heater core will have to be replaced.

in the cab, but procedures are different depending on whether or not you have A/C. See below

1980-81 Comfort Vent Heaters, Without Air Conditioning

1. Disconnect the heater hoses from the heater core tubes and plug the hoses with suitable 5 / 8 inch; (16mm) plugs.
2. Remove the glove compartment liner.
3. Remove two (2) spring clips attaching the heater core cover to the plenum along the top edge of the heater core cover.
4. Remove eight (8) screws attaching the heater core cover to the plenum and remove the cover.
5. Remove the heater core from the plenum taking care not to spill coolant from the core.

To install:

1. Install the heater core in the plenum.
2. Install the heater core cover (eight (8) screws and two (2) spring clips along the top edge of the cover).
3. Install the glove compartment liner.
4. Connect the heater hoses to the heater core. Tighten the hose clamps.
5. Add coolant to raise the coolant level to specification.
6. Check the system for proper operation and for coolant leaks.

1980-81 Standard & High Output Heaters, Without Air Conditioning

1. Disconnect the temperature cable from the temperature blend door and the mounting bracket on top of the heater case.
2. Disconnect the wires from the blower motor resistor and the blower motor.
3. Disconnect the heater hoses from the heater core and plug the hoses with suitable 5 / 8 inch; (16mm) plugs.
4. Working under the instrument panel, remove two (2) nuts retaining the left end of the heater case and the right end of the plenum to the dash panel.
5. In the engine compartment, remove one (1) screw attaching the top center of the heater case to the dash panel.
6. Remove two (2) screws attaching the right end of the heater case to the dash panel, and remove the heater case from the vehicle.
7. Remove nine (9) screws and one (1) bolt and nut attaching the heater housing plate to the heater case, and remove the heater housing plate.
8. Remove three (3) screws attaching the heater core frame to the heater case and remove the frame.
9. Remove the heater core and seal from the heater case.

To install:

1. Position the heater core and seal in the heater case.
2. Install the heater core frame (3 screws).
3. Position the heater housing plate on the heater case and install the nine (9) screws and one (1) bolt and nut.
4. Position the heater case to the dash panel and install the three (3) attaching screws.
5. Working in the passenger compartment, install two (2) nuts to retain the heater case and plenum right end to the dash panel.
6. Connect the heater hoses to the heater core. Tighten the hose clamps.
7. Connect the wires to the blower motor resistor assembly.
8. Connect the blower motor wires.
9. Position (slide) the self-adjusting clip on the temperature cable to a position approximately one 1 inch; (25.4mm) from the cable end loop.
10. Snap the temperature cable on the cable mounting bracket of the heater case. Then, position the self-adjusting clip on the door crank arm.
11. Adjust the temperature cable.
12. Check the system for proper operation.

Hi my name is Allen!

First let us check to see if it is the heater core, follow the test procedures below.

1-Check the coolant level, if its full move to the next procedure, if its low fill it and recheck the heater operation.

2-Bring the engine to operating temperature, check the heater core by grabing one of the hoses and see if it is extremely hot, if it is, move to the next hose, if it is luke warm and not extremely hot you have a heater core plugged up. If both hoses or cold or warm you may need a thermostat because it may be stuck open.

3-If the heater system has a heater control valve installed in one of the heater hoses you will need to bypass the valve to see if it is plugged, if it doesn't have a valve forget about this procedure.

4-If you find that the heater core is plugged, you can put a can of coolant system cleaner in the radiator and drive it for a week and then take off the heater hoses, both of them NOTE: make sure the system is cool so you don't get burn't! Then you will need to back flush with a garden hose from one side of the hose outlet to the other through the heater core itself.

NOTE: if this doesn't help you will need to replace the heater core!

For further assistance reach me at FixYa!

SOUNDS AS THOUGH THE HEATER CORE IS PLUGGED. TRY BACK FLUSHING IT AGAIN. IF YOU STILL GET NO FLOW IT IS MORE THAN LIKELY PLUGGED AND WILL NEED TO BE REPLACED. THE TUBES ARE VERY SMALL AND PLUG EASILY WITH RUST.