Heater core replacement?

No way to repair it, you can bypass it but this will leave your heater system inoperative.. to bypass heater core just disconnect both heater hoses at firewall and then add a third piece of heater hosing between the two disconnected from firewall. Here are the instructions on how to get the core out in the diagrams below. This guide can help as well

https://www.2carpros.com/articles/replace-heater-core

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Anytime there is an airbag involved it's best to disconnect the battery. You'll have to see about puling the dash, I think you do but most of the time if you loosen it an dpull it back a little way you may have engouh room for the heater core. You can go on the site here and buy a 3 day manual for $10 and look it up and print it soyou would have it step by step availability.

My labor guide calls for 8 hrs with a/c. That means the entire dash has to come out of the truck far enough to get the entire HVAC plenum out from under the dsh. Not a DIY project fo the weak of heart. Need to have the a/c evacuated and then vacuumed down and recharged when done

Remove the HVAC module. See: Heating and Air Conditioning Housing Assembly HVAC Service and Repair
Remove the heater core access cover screws.
Remove the heater core access cover.

Remove the heater core from the HVAC module.
INSTALLATION PROCEDURE

Install the heater core to the HVAC module. NOTE: Refer to Fastener Notice in Service Precautions.

Install the heater core access cover. Tighten Tighten the heater core access cover screws to 1.9 N.M (17 lb in).
Install the HVAC module. Refer to Heater/Vent Module Replacement.

Unfortunately, we don't have that level of detail on any of the procedures or guides. However, from memory they are normally 5/16 socket.

https://www.2carpros.com/articles/replace-heater-core

If you can, get a picture of what you are dealing with and we may be able to identify the size just by looking at it. However, if the ones you are talking about are those "hidden" bolts, unfortunately you may have to do it by feel because hopefully if this was ever done before the correct size bolts were put back in. Thanks

Just following up on this. Is this the bolt that you are talking about? See the attached.

If it is, then I believe these are 8 or 10mm. However, most people drill a hole in the plastic housing in front of the bolt and then they can get an extension in a more direct line. I circled the location people do this and then they will need to use a sealant of some sort to seal the hole.

Adding to what Kenny said about that particular bolt, ice done that job a couple of times. It's a 10mm bolt. I never bothered putting it back in when reassembling because there are plenty of other bolts to hold it all together. But if you really do want to put it back in there, then do as he says with drilling and using a ratchet with a long extension.

Sorry to hear that. That is the worst when you get something like this done and it is rattling. Unfortunately it is hard to recommend what this could be other then how to try to identify it. The best way I have done these is have someone else drive and I would put pressure around the dash to try and narrow the area it is coming from.

Let us know if there is a way you need us to help. Thanks

Could be a piece of the defrost vent went down into the HVAC box. Try running it on high fan speed while switching the modes back and forth. If it stops then you e probably solved the problem and it'll come out of the floor vent when you go around a corner.

It could also be just the nuts on the metal cover that sits below the steering column. I didn't get that completely tightened the first time once and it made quite a racket.

You are welcome. Thanks for the info on that. I am sure that will help others. Please come back to 2CarPros in the future if you need help on other issues. Thanks