Heater core

[ColoradoSilverado]

Can anyone tell me where exactly the heater core is located? (2000 Silverado).
Is it like in the center behind the dash? I'm loosing coolant at a very slow rate, my heater doesn't get very warm anymore and I can sometimes smell coolant in the cab. Just wondering if I can stick my hand in there from underneath the dash and maybe feel if there's moisture...

Thanks in advance!

[j cAT]

DON'T JUST PUT STOP LEAK IN IT. CLEAN THE CORE FIRST.

I would disconnect the heater core hoses at the engine and flush out the heater core until it flows with no restrictions in both directions. then blow out the heater core with some air to remove any coolant. using a pressure gage ,,,place about 15 psi of air into the hose and see if it holds pressure. then you will know if its leaking.

If it is leaking then I would use some of bars stop leak . I would premix firt in some dexcool and install into the top radiator hose. close up the system purge as per instruction and see if the leak stops in a few drive cycles.

If the leak continues this will require the complete dash removal. some screws are very hard to get at. not a fun job.

heater core is next to the glove box on the driverside of it. removal of the air filters you should be able to see a portion of it.

[ColoradoSilverado]

Thanks jCat, I will dive into that after X-mas, wasn't even thinking about of putting stop leak in it, I'd rather replace it.

[j cAT]

lets see if you say that , after you change out the heater core.

thats even IF the core is the leaker.

my guess the leak is the water pump gasket area. the core is still a good posibility..

re torque water pump bolts and put a little stop leak in it after you clean out and test the heater core..

[gremlin96]

stop leak is like putting bubble gum in a motor. something no person in there right mind would do.

flush out the motor and core. block off the core, pressure test it. 5 lbs should be good. to much and you will have problems. most systems have a cap that will blow at 15 lbs in the radator. but on the newer trucks i have not found such a critter. a hour or two if you do not lose pressuer on the heator core its should be good. if its good your going to need to start checking all the hoses, and gaskets for signs of leaks.

buy a new heator core, you do not know what the used one has had in it.

[j cAT]

Originally Posted by gremlin96

stop leak is like putting bubble gum in a motor. something no person in there right mind would do.

flush out the motor and core. block off the core, pressure test it. 5 lbs should be good. to much and you will have problems. most systems have a cap that will blow at 15 lbs in the radator. but on the newer trucks i have not found such a critter. a hour or two if you do not lose pressuer on the heator core its should be good. if its good your going to need to start checking all the hoses, and gaskets for signs of leaks.

buy a new heator core, you do not know what the used one has had in it.

well with 30 plus years of using these STOP LEAK products in clean coolant systems that have been -properly maintained I find your comment not to my real life findings. usage of the correct product in the proper way does work and will save much on down time and costs.

also these engine run at 15psi pressure. this is to keep the coolant from boiling. In high elevations you best be sure that you have no leaks and can get 15psi or it will boil over/heat etc.

with the coolant/water removed the air pressure test will quickly show if the core has a leak which I doubt. more than likely its the water pump gaskets that are very hard to find until it gets bigger.

[gremlin96]

stop leak is a short cut in a can. is what a old race car driver and auto parts store owner calls it. it was the second generation to run that store. his dad started it back when there was model A's running around.

do you know how to stop a leak on a model a cars radiator. its very simple. you reach in your lunch bucket, get a few spoons of pepper and put it in the radiator. fill it up and drive on. fill as needed. it pepper will clog up that hole if its a small one. you still have the hole but it will be a very slow leak.

too do a system pressure test, unless your testing the cap. there is no need to have a high psi. if it holds it will hold for a very long time and there is no leak in the system.

my first question is what caused the loss of any fluid. a bad seam, weld, metal degradation, bad hose, gasket. then repair or replace failed parts.

[MikeD268]

Just had to deal with this CS.... http://www.automotiveforums.com/vbul....php?t=1084751

I was slowly losing coolant for a few weeks. Got the occasional whiff of it in the cab and the heat wasn't great. Decided to flush the system and in the process of installing the flush kit, one of the heater hoses literally fell off of the firewall connection. I'm guessing that Dex-cool and high temp fluctuations aren't overly kind to plastic. As yours is the same age as mine, just be prepared for that if you haven't replaced those quick connects in the last few years. I lucked out in having the flush kit handy as the flush tee was long enough to make up the difference that the quick connect added in to the hose length.

May not be a bad idea to have a few extra parts on hand just in case...

[ColoradoSilverado]

Thanks for all the replies, I haven't looked at it yet, it's been cold here. Might look at it tomorrow or Tuesday, have to check the water pump too (254,000 miles on it).

[danielsatur]

If there's an external vent for the HVAC, it's probably drawing the smell from an external leak, there should be some evidence of leakage inside of the cab for a bad heater core.

Profile:
Condition - Excellent, if current pix
Age-12years/ Mileage-245k/ Dex-cool?

Was the coolant auxiliary tank contaminated ?
How many times was the coolant changed during life of truck?

It's probably best to replace all the rubber hose's, water pump, thermostat, coolant aux tank, and coolant with Prestone Extended life.

The water pump, any plastic, and rubber hoses are going to bad, because of age + mileage, lets see another 245K miles without any coolant problems.

If you still have any problems with a coolant shortage try Metallic block seal, blue devil sealant, or www.steelseal.com

[j cAT]

before replacing anything find the leak that would be step one.

you can create more problems by replacing parts first.