On the way to work this morning I couldn't see out the windshield. So I pulled over, popped the hood and opened my heater core valve. Im excited as I like the colder months around here so flipping the valve means it's getting close!

However, much to my surprise I found the heater blowing cool air on the windshield all the way to work and every time the sun hit the windshield I was 97% blind to where I was on the road other than looking out the windows that were rolled down. My first thought is it's air from when I put this engine in earlier this year. I never bled the cooling system, I flushed it with 40-50 gallons of distilled water after flushing with a water hose for a decent amount of time. I then reinstalled the 1 block plug that I was able to get out and filled up with ELC. The distilled water coming out the block while flushing wasn't 100% clean but it was soo close and I was out of distilled water so I ran with it. But that was all I did. I didn't bleed Anything.

Anywho, if that is The case, i will bleed it when I get home. Surely its not as easy as popping off a hose?

If that's not the case, what Else can stop my heater from working?

So, In other news, I swapped my IDM with my spare that came off the parts truck that my engine came out off. It seemed to me this engine was less clackety while it's home was in the parts truck. So I thought of course I've got single shot injectors which doesn't help. But I was just curious so I swapped the IDM. I would swear the engine is considerably less clackety and sounds better at idle. I had my good friend ride with me and he said the same thing. Are we crazy or is it possible that the IDM is possibly original and was causing some odd noise?

How did everybody fair with hurricane Helene?

 

Did the blend door motor go out?

I imagine a weak IDM could cause some cackle.

 

If the heater valves were closed when you did the work it's possible that uts just trapped air, a few up to temp runs should bleed the heater core out, unless the coolant got stagnant and clogged the heater core then a heater core flush is needed.

 

With the engine up to temp you should be able to carefully feel the hoses at the firewall. If they both aren't hot then there isn't any flow through the core and it's either air locked or plugged. If both are hot then possibly a blend door thing or maybe the AC compressor isn't cycling to dry the air. I remember my old Toyota's couldn't do crap for foggy windshield no matter how hot the air blowing from the vent because no AC to dry the air.

 

I second the blend door motor as the culprit.

 

Ill check it out! Thanks!

Interesting. New question. Could a weak IDM cause early Injector failure? Wondering if it may have played a part in my injector failure that took my original engines #2 cylinder. Although it doesn't seem likely to me that be the case. Just a thought.

 

Heater valve was closed during my engine swap. This was my first time needing heat here in LA (lower Alabama) with our 120+ degrees summers. And it's definitely not cold, just cool enough to fog the windshield in the mornings. The coolant shouldn't be stagnant I wouldnt think. It's rotella ELC. I did my engine swap in March.

 

I will have a new blend door tomorrow. Easy enough to change and worth a shot. I did try to feel the hoses after warming the truck up to see if they were warm but, being as they are in an engine bay, they were both pretty warm. While I was inspecting the blend door thingamajigger, the dash felt hot. Like something was radiating heat. Where is the heater core located on these trucks? It may have been the heat from the heater core that I was feeling which would be more evidence that the blend door is the problem. I guess we will see tomorrow! So, I've had a humming noise around 40 mph while accelerating for probably a couple months. Only did it at specific speed and only if you were accelerating. If you were cruising you couldn't hear it. Didn't think too much of it but it's been driving me nuts so I checked my transmission fluid which was good although it was 1 quart over filled when I filled it last so it is a little low compared to what it was filled to but it's still at the fill plug. Once that checked good I decided to check the rear axle fluid to find that I could not reach it with my pinky finger. It was one quart low. There was also a 1/4" thick pile of metal on the fill plug magnet. Good thing I have a limited slip rear axle ready to go under it. Speaking of the limited slip rear axle, I was thinking about resealing it and replacing the hub bearings and whatnot. Is there possibly a kit for the hub bearings and seals? I will also do a fluid change and if there's any seals for the axle that are easy enough to replace I would like to do those as well. Good news is he had new leaf springs installed shortly before selling the truck. Perfect! I've got good brake calipers on my axle that I will swap over and I already have some severe duty pads for the front and rear of the truck that I will also put on. But, until I have time to do that, for now I'm going to pull the plate off the back of the current axle and clean up all the metal shavings and put some new fluid in it and run it for a week and drain it again.

 

The heater core is in the HVAC box pretty much directly behind the glove box. Well, technically it's forward of the glove box, but you know what I mean, lol

 

You ordered a blend door or blend door motor? The motor sits on top of the HVAC plenum where the heater core is. Pikachu has you pointed in the right direction for its location.

 

The motor I think is all I ordered. Unfortunately I didn't make it there to pick it up today. Just got home. I'm exhausted and it's been a long day LOL

So if the blend door sits right on top of the heater core then I would have to say that's probably more evidence that the blend door motor is probably bad. That was the box that I was touching and it was hot hot after a drive home from work.

 

Blend door motor installed. Heat has been restored! Thanks everyone for your help!

 

So that's how that works. I always wondered why my mom's SUV would clear the windshield seemingly instantly while my truck took a little bit even though the heater in my truck blows around the temp of lava.

 

Sometimes I will run the AC on cool with the intake set to pull air from the cabin in a vehicle that has windows fogged up. Once the windows are clear, switch to heat so that we stay comfortable.

 

Good to know, I'll have to try it out! Thanks!