Coolant system problems... can't seem to diagnose cause

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
Hey everyone, hoping I can gets some help here.

I have a 2005 Ram 5.7L Hemi.

About 3 weeks ago, I found a small leak in my radiator. Not sure how long it had been going on but it wasn't obvious. As a quick fix until I had time to work on it, I used some Bar's Stop Leak and monitored it for a couple days. The leak did not improve and in fact, got significantly worse. Not sure if the Stop Leak had something to do with that.

I ended up draining and flushing the system, replaced the radiator with a new one and bled the system using the half full funnel and burp procedure. Since replacing the radiator, my heat has not returned to normal levels on the drivers side and I smell a faint hint of coolant. Non on the windshield running defrost and no leaks on the floor boards, even three weeks later. Fluid levels also appear to be stable.

I assumed the heater core must have a clog so today I tried a flush using a garden hose. I ran water in both directions and the fluid was exceptionally clear. No junk at all. I put everything back together and burped the system again, this time for over an hour revving the hell out of it throughout. The heat actually got hotter on the passenger side but still no effect on the drivers side. Still no signs of a leak anywhere.

Not sure what else to try aside from ripping out the heater core, which I really don't want to do. I'd think if it was bad or had a leak, I'd be seeing signs of it, i.e. on the windshield or passenger floor boards, but nothing.

Is it possible to have a clog in the heater core that even when flushing, shows no signs of junk or dirty coolant?
 

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
Are you saying only one side of the heater core is getting hot, or are you only getting hot air from one side of the dash?

If it’s hot air only on one side, I’d be looking at the ducting, or blend controls.


Sent from my iPhone using Tapatalk
 
OP
OP
C

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
Are you saying only one side of the heater core is getting hot, or are you only getting hot air from one side of the dash?

If it’s hot air only on one side, I’d be looking at the ducting, or blend controls.


Sent from my iPhone using Tapatalk

Hot air on the passenger side of the dash only. And to clarify, the driver side air from the dash gets "a little" warm but no where near what the passenger side does or what it used to get. And it really starts to cool down at idle or if I crank up the flow.

I've considers the blend controls but the smell of coolant and that none of this started until I used the Bar's Stop Leak and replaced the radiator has me thinking it's something in the cooling system.
 

muddy12

Senior Member
Joined
Jul 26, 2016
Posts
1,030
Reaction score
800
Location
Indiana
Ram Year
2012
Engine
5.7 Hemi
have you checked the temps of the heater hoses?
Once the engine is warm, both heater core hoses should be close to the same temp. If the outlet is considerably cooler, something is blocking the flow of coolant.

Quote: "Is it possible to have a clog in the heater core that even when flushing, shows no signs of junk or dirty coolant?"

yes, it is possible to have a partly blocked heater core. The heater core is basically a small radiator, and it is possible for only some of the tubes to become blocked.

I'm assuming you have AC? If so, when you were checking for leaks, did you check under the truck? Specifically the condensation drain tube? Heater core "could" be leaking into the duct work, and the coolant is making it's way out via the condensation drain and not leaking into the cab.
 

JohnnyMac

There are no stupid questions, just stupid people.
Military
Joined
Mar 31, 2018
Posts
2,558
Reaction score
2,920
Location
SouthWest Washington
Ram Year
2018 1500 Laramie
Engine
3.0 EcoBurner
The heater core may have already been a little plugged and the Bars Leak may have finished plugging it up, or the flush you did could have broke some gunk loose that got jammed in the heater core. You're probably gonna have to pull it and check.
 
OP
OP
C

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
have you checked the temps of the heater hoses?
Once the engine is warm, both heater core hoses should be close to the same temp. If the outlet is considerably cooler, something is blocking the flow of coolant.

Quote: "Is it possible to have a clog in the heater core that even when flushing, shows no signs of junk or dirty coolant?"

yes, it is possible to have a partly blocked heater core. The heater core is basically a small radiator, and it is possible for only some of the tubes to become blocked.

I'm assuming you have AC? If so, when you were checking for leaks, did you check under the truck? Specifically the condensation drain tube? Heater core "could" be leaking into the duct work, and the coolant is making it's way out via the condensation drain and not leaking into the cab.

Both hoses are warm. Could a partially clogged heater core lead to the antifreeze smell in the cab? Or would only a leak cause that?

I'll also check the condensation drain. I haven't checked that yet but I'm not seeing any noticeable fluid stains under the truck.

The truck overall has done really well for me, 205k miles over 13 years, but seems to be failing in a number of places all at once now. In the last 2 months I've had the... fuel pump, oil pressure sensor, and radiator fail. I also think one of the pulleys has a bad bearing. The engine is making a strange sound like something that spins is slightly off center, although I can't pinpoint which one.
 
OP
OP
C

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
The heater core may have already been a little plugged and the Bars Leak may have finished plugging it up, or the flush you did could have broke some gunk loose that got jammed in the heater core. You're probably gonna have to pull it and check.

Dang... that's what I'm hoping to avoid. What do you think about flushing it with white vinegar and letting that sit for a day or so? I guess at this point, it's worth a shot before pulling out the dash.
 

JohnnyMac

There are no stupid questions, just stupid people.
Military
Joined
Mar 31, 2018
Posts
2,558
Reaction score
2,920
Location
SouthWest Washington
Ram Year
2018 1500 Laramie
Engine
3.0 EcoBurner
Dang... that's what I'm hoping to avoid. What do you think about flushing it with white vinegar and letting that sit for a day or so? I guess at this point, it's worth a shot before pulling out the dash.

Well, that would certainly be an easy thing to do prior to pulling it, but I kinda spaced the fact you are smelling coolant. Might be that it's plugged up/corroded and with all the stuff done to it since you had the leak in the radiator, it may have a pin hole due to that corrosion and although small, the fan is blowing the coolant smell into the cab. Hard to see an easy out here, you're probably in for a bit of work.
 
OP
OP
C

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
I hate to say it but I think you're right JohnnyMac about it having a small pin hole leak. I noticed the last couple days that when I start it up after it's been sitting overnight or while I'm at work, I can smell it strong. After it's been running awhile, it generally goes away. It's like it has a small leak that builds up when sitting for awhile and gets burned / blown off after running for some time.
 

Arth

Senior Member
Military
Joined
Jan 15, 2013
Posts
958
Reaction score
735
Ram Year
2022 Ram 3500 Crew Cab Limited 4x4
Engine
6.7 HO Cummins Turbo Diesel
Do you have dual zone AC?

Sounds exactly like a blend door issue. Had this exact problem on my Avalanche. GM uses 4 blend doors to control the air conditioning. If the blend door controlling the driver side temp has failed then I suspect that's the issue.
 
OP
OP
C

copperking81

Junior Member
Joined
Dec 9, 2018
Posts
6
Reaction score
1
Location
Virginia
Ram Year
2005
Engine
5.7 Hemi
No, it's not dual zone. Could a blend door problem lead to the antifreeze smell in the cab? I wouldn't think so but not sure.
 

Arth

Senior Member
Military
Joined
Jan 15, 2013
Posts
958
Reaction score
735
Ram Year
2022 Ram 3500 Crew Cab Limited 4x4
Engine
6.7 HO Cummins Turbo Diesel
No, it's not dual zone. Could a blend door problem lead to the antifreeze smell in the cab? I wouldn't think so but not sure.

No I don't think so either. Just with what you were describing sounded identical to what I had delt with in another vehicle minus the coolant smell.

The Avalanche had a coolant odor too but it was more pronounced around the engine bay. Turns out my radiator cap was failing.
 
Top