Low engine coolant and heater issues

[messyj232]

Hey everyone-
If this is already posted, I apologize.
My heater doesn't work great on a high level. It works fine on a lower fan level (1 or 2) however if I crank it up (level 3 or 4) it does not blow out really hot air.

I noticed that my engine coolant was near the minimum level so I filled it up near maximum hoping that would solve the issue. I thought the heat maybe worked a touch better, but now I am not so sure.
Any advice would be greatly appreciated. I am fairly handy with the truck and have done a bunch of work on it before.

 

[HolyRamBatman]

Welcome to RF.

Does the fan blow harder when turned on high? What did the coolant look like, any gunk floating at the top or in the puke tank?

You could have a t-stat not stuck open not allowing the engine to warm up quickly.

You could also have a blockage in the heater core.

Others will chime in soon.

 

[messyj232]

Welcome to RF.

Does the fan blow harder when turned on high? What did the coolant look like, any gunk floating at the top or in the puke tank?

You could have a t-stat not stuck open not allowing the engine to warm up quickly.

You could also have a blockage in the heater core.

Others will chime in soon.

HolyRamBatman-
Thanks for the quick reply! No it does not seem to blow harder when turned on high heat. Not sure what the coolant looked like, it just looked really low. No gunk floating at the top.
I have 180,000 miles on my truck. I personally have never put engine coolant in it before (not to say that a mechanic didn't).
I usually allow the truck 10 minutes to warmup in the cold before before I drive.

I don't know if this is related but when I start the truck, I feel like the engine or a fan is really loud for about 20 seconds before it quiets down. This is especially true if it hasn't run for more than a day.
Thanks again!!!

 

[HolyRamBatman]

When you turn the fan on high it should blow harder. Kinda obvious. If it doesn't you either have a switch, relay or fan motor going out.

When the fan is on low is the air hot and blowing slow?

And when the fan is on high is the air hot and still blowing slow?

 

[messyj232]

When you turn the fan on high it should blow harder. Kinda obvious. If it doesn't you either have a switch, relay or fan motor going out.

When the fan is on low is the air hot and blowing slow?

And when the fan is on high is the air hot and still blowing slow?

HolyRamBatman-
I misunderstood. Yes, it blows harder on the high level. When it is on low, the air is real hot (like it's supposed to be) and blowing out slowly.
When it's on high, the air is blowing out quickly, but it's not that hot.

 

[HolyRamBatman]

Ok then you have a heat problem and not a fan problem.

2 things come to mind. The heater core is slightly clogged or the blend door is not opening all the way.

Clogged heater core should be relatively easy. Unhook both hoses that run into the firewall and run water into one of the hoses and see what comes out the other hose. Then do the same to the other hose. Don't put a lot of pressure through there but enough to dislodge anything that might be in there.

Be gentle with the hoses so you don't break or crack them.

The blend door is another issue. I have read about it but am not 100% sure on the procedure. There is a thread on it here on RF.


These are the things that come to mind. Hopefully someone else will jump in to confirm or add to.

 

[HolyRamBatman]

The engine or fan that is loud the first 20 seconds, does it sound like you are strangling a cat?

 

[messyj232]

The engine or fan that is loud the first 20 seconds, does it sound like you are strangling a cat?

Haha no. It just sounds REALLY LOUD.

 

[messyj232]

Ok then you have a heat problem and not a fan problem.

2 things come to mind. The heater core is slightly clogged or the blend door is not opening all the way.

Clogged heater core should be relatively easy. Unhook both hoses that run into the firewall and run water into one of the hoses and see what comes out the other hose. Then do the same to the other hose. Don't put a lot of pressure through there but enough to dislodge anything that might be in there.

Be gentle with the hoses so you don't break or crack them.

The blend door is another issue. I have read about it but am not 100% sure on the procedure. There is a thread on it here on RF.


These are the things that come to mind. Hopefully someone else will jump in to confirm or add to.

HolyRamBatman -
Thank you so much! I will look into checking these two issues out over the weekend.

 

[HolyRamBatman]

Your welcome. I hope it helps.

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[Trupiano]

What do your operating temperatures look like? As stated, another option would be your thermostat is stuck open, and so always cycling fluid through your radiator, so it never is able to reach normal operating temperature.

Coolant flush, new thermostat would probably be a good idea anyway. Then i would address possible problems with the heater core or heating/cooling vent doors.

I know where I work, on the diesels they were removing the thermostat... needless to say, it would never blow hot air, only semi warm : (



EDIT:

This will help you with a possible blend door problem. All kinds of info.

http://www.heatertreater.net/Ram 02-08 Listing.html

And they have parts to fix!

 

[messyj232]

What do your operating temperatures look like? As stated, another option would be your thermostat is stuck open, and so always cycling fluid through your radiator, so it never is able to reach normal operating temperature.

Coolant flush, new thermostat would probably be a good idea anyway. Then i would address possible problems with the heater core or heating/cooling vent doors.

I know where I work, on the diesels they were removing the thermostat... needless to say, it would never blow hot air, only semi warm : (



EDIT:

This will help you with a possible blend door problem. All kinds of info.

Dodge Ram 2002, 2003, 2004, 2005, 2006, 2007, 2008, blend door auto AC heat replacement part

And they have parts to fix!

Trupiano-
I'm not sure about operating temperatures, but what I do know is when I have the heater cranked all the way up it only blows out lukewarm air. On lower settings it is hot air, though.
Could that be a thermostat issue?

 

[Trupiano]

No, if it was the tstat you'd never get hot air. Blend door, heater core, or possibly the rheostat knob needs to be replaced. Only things I can think that it could be.

El Phono

 

[Trupiano]

Would be a good idea to feel the two lines running into/out of the firewall. They're the heater core in and out lines, and after the truck is warm/hot, they should be about the same temperature. Good way to op-check the heater core, and see if it could possibly be the problem.

 

[messyj232]

Would be a good idea to feel the two lines running into/out of the firewall. They're the heater core in and out lines, and after the truck is warm/hot, they should be about the same temperature. Good way to op-check the heater core, and see if it could possibly be the problem.

Trupiano-
Thanks so much!
I may just cave and take it to my mechanic though... Bah humbug

 

[HolyRamBatman]

Gotta try first. Do the easy stuff and see what you get.

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[Wchnu]

Any update in this. I have a $5 bet on the heater core plugged.


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[Joshua]

Hi, I'm having a slightly similar issue and the comments here are very helpful, I will be looking into them over the weekend when I get home since I travel for a livin.
However I do have another issue/question that I believe to be related. Then again maybe not. I've had someone tell me it may be an Evap issue due to vacuum hose leak somewhere. Anyways it's like this, when I turn my fan on high it blows good speed and everything but when I switch it to hit from cold sometimes it will not do anything. I'll have to keep messing with it back and forth on and off until I hear a loud flop under the dash. Rare instances have happened where this yielded nothing but most times I know that it's swapped over to heat now. Mine still isn't getting as hot as I think it should. And if I'm not mistaken it does this whether you go from hot to cold or cold to hot. Something else interesting is that I can sometimes just turn the fan down or off for a sec and I'll hear that flop noise when I'm trying to make it change, it's a little quieter but I imagine it's because the fan isn't on high. And check this, I have come up to a light and stopped and heard it as soon as I stopped. Then I gotta take off and get to speed and mess with it again til it switches back. If you're parked and just idling, then heat will just about not switch on at all and I think the ac barely works. I can hear two more noticeable noises that I need help identifying. One kick on and off it literally sounds like a little fan somewhere that's noisy or maybe the blades rubbing somewhere and last but not least, a whooshing or rushing of air through maybe some small tubing(I picture ac) it comes and goes as well. Can hear none of these of course when the fan is all the way off. Something tells me vacuum hose somewhere for the Evap but I'm just figuring all this stuff out as I go. I have no idea where all the hoses for the Evap are located. Guess an Evap hose route diagram Google wouldn't hurt huh?

Any ideas on what that could be?


2003 Ram 1500 4.7 magnum 4x2
196k miles but well taken care of.


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[Joshua]

Oh yeah and I forgot to mention I hit a sudden bump I the road the other morning at about 50mph and the flop noise occurred and all of a sudden blowing cold. I was so mad..


2003 Ram 1500 4.7 magnum 4x2
196k miles but well taken care of.


Sent from my iPhone using Tapatalk