Could my rear auxiliary heater core have a blockage?

There could be a few possible causes for the rear heater not blowing hot air in your 2003 Chevrolet ASTRO van. Here are a few things you could check:

1. Make sure that the rear heater control valve is fully open. This valve is located near the heater core and controls the flow of coolant to the rear heater.
2. Check the coolant level in the radiator. If the coolant level is low, the heater may not be able to produce hot air.
3. Check for any leaks in the coolant system. If the system is leaking, it may not have enough coolant to produce hot air.
4. Check the thermostat. If the thermostat is stuck closed, it may not be allowing enough coolant to flow through the system to produce hot air.

If these steps do not help, it is possible that there is a problem with the heater core itself, or with other components of the heating system. It may be necessary to have a mechanic diagnose and repair the issue.

Rear heater core or line running to the rear heater core

If you have a coolant leak at the rear of the engine, there are not too many choices that it could be. Either the turbo itself, the coolant hose to the turbo, or possibly a hose going to the heater core.

Rear heater core or hoses going to or from it must be leaking? You have to take the cover off the rear heater assembly to fix it on most vehicles. don-ohio (:^)

U must connect the coolant in hose to the coolant out hose with a u type metal hose by passing the heater core all together

Hi Lerverne,here' a link on your rear heater core. Repair Guides Auxiliary Heating Air Conditioning Heater Core AutoZone com Here's a link to a new rear heater core. Spectra Premium Heater Core

There is a set of two steel pipes that carry coolant/antifreeze to the rear mounted heater core for heater operation. These steel pipes/tubes rust out, and you end up with a coolant leak. Mitsubishi has superceded the steel tubes with aluminum tube set. Not an easy job to replace the two pipes since they are routed over and around a few items under the vehicle before attaching to the heater core at the r/r of the vehicle.

Hi, this is the heater core for your rear heater. If it's leaking from inside the box, it's likely the core is bad. Please let me know if you would like instructions for replacing the rear heater core. A new core is $92 at autozone, but I would shop around. Make sure you specify the rear or auxiliary when ordering a new new core, as the front core is different.

If the vehicle has a rear passenger heater, it may be that the coolant is leaking from the heater core or one of the hoses connecting the heater with the engine cooling system so you would need to get under the vehicle and visually check. This may also be a leaking heater core under the dashboard and the coolant is flowing over or under the carpet and pooling in the rear footwell.
Check for damp or wet spots in the carpet from the front to the rear of the vehicle with your hand and carefully check around the area where the heater core is mounted, this is usually undr the centre of the dash or behind the glove box. If this is found to be the area of the leak then the heater core will need to be removed and replaced or repaired. Removing the heater core is quite a daunting job as nearly all of the dashboard and fascia have to be removed along with all the electrical items mounted in this area. You may be able to bypass the heater core by connecting the two heater hoses under the bonnet together with a small length of pipe and then check to see if the coolant returns to the footwell. If it does not then the core is faulty. if it does then the issue may be in the rear heater (if fitted) and should be bypassed and checked in the same way.

Fuel gauge problem is the sender card inside the tank very common problem.Horn could be contact problem inside steering wheel,heater could be coolant level or heater core blockage other things will need to be diag.