RAM TECHS--08 HEAT NOT HOT

08 hemi--everything seems to work just not blowing hot--sort of very luke warm on the heat after extended driving and warm up Any ideas what to check? Thanks

Have you checked the temp at the in and out heater hoses? What does the engine temp gauge read? If they are all good then the issue could be the blend door not working right.

Has the coolant system ever been serviced? If the system was opened at anytime for parts replacement, there might be an air pocket. Maybe there is blockage in the heater core if the system has never been flushed.

As stumpy said, check the temp of the hoses in and out. If they're consistent, check the blend door. If not, check for air or blockage.

Reverse flush your heater core.

My 2013 300 has required all 3 blend doors to be replaced. They can allow a mix of hot/cool air. Does one side blow hotter than the other?

Not uncommon for those blending door motors to break. Inexpensive part. They all look the same but there can be minor differences/part numbers between the cars, SUV's and Rams, mostly due to the housing mounting holes locations.

I have an 03 1500. Does not have split control heater. My blend doors are fully functioning, have no issue with air directing to defrosters or floor. I drilled a hole in the heater box to check door. I drained some antifreeze out and ran with cleaner added to water for two weeks. I then flushed heater core, got a bit of rust out of it, ran garden hose to both sides multiple times until nice and clear. Drained by lower radiator hose and added new antifreeze. Let truck warm up to temp and had hot air blasting through heater/defrosters. Test drive down the road and then a gurguling sound from dash, and heat goes away, barely warm on lowest blower setting. These get air locked? Cap no good? I’m back to where I was before, but I had it working on the first part of test drive, doesn’t plug up that fast

And I hooked up hoses reversed to heater

Gurgling in the dash is an indication of low coolant and also why you lost heat.
Did you check the level after your test drive? Not familiar with the Ram cooling systems so I don't know if there's a trick to getting the air out. You may have to pull the heater hoses and fill the core that way.


Tim

I had to add some. Probably will pull hose and see how much coolant comes out, that may tell me if it is air locked. May try a new rad cap to make sure system gets some pressure.

You could try parking with the front end higher than the rear and let nature do it's thing.

I did that as soon as I put it back together, before the test drive and initial warm up. Going to try again this weekend, warm weather in Sunday. I’ll put the hose to heater core to make sure it’s full of water and park it uphill

I would pull both. Fill through one and the other will allow any air to be pushed out.


Tim

Here’s the update! I removed air filter box and I have two inline hose connections on the hoses there. I had reversed hoses last time. Today I put the 5/8 garden hose repair fitting on my garden hose nozzle, they are threaded! I can control the water that way. I pinched the hoses off with clamps on the engine side on the fittings. Then I took connectors apart. I put the nozzle in one hose and put the water through it. First comes antifreeze, then a lot of rusty looking water, then clean water. Went back and forth flushing both ways, then connected hoses and warmed engine. I now have heat as it should be. It is working fine, drove a few times today and working great! So, between the cleaner, swapping hose connections, and a couple flushes, it’s done!