Oops...now heaters not working!

[Texican65]

Hi guys,

My ‘89 Ranger had a small radiator fin leak...so I dumped in a bottle of “K-seal” coolant leak repair. Fixed the leak...but now my heater is putting out luke warm heat.

What’s the most likely culprit to be clogged up...thermostat, heater core, mixing valve, control valve?

Or could it be something else?

Thanks,

Dow

 

[Texican65]

Or...

When I went to dump this stuff in the radiator, there was no room for it, so I let the truck warm up with the cap off, when it warmed up...and the T-stat opened, it belched some coolant out. I added the “sealer” and also some more coolant. Could there be air in the system somehow fouling things up?

 

[MikeG]

Probably 'sealed' up the heater core.

 

[Texican65]

Probably 'sealed' up the heater core.

Thanks Mike. I was worried that might be the case. Can the heater core be flushed or cleaned out with something...or just order a new one?

 

[RonD]

After engine is cooled down remove the heater hoses at the firewall, you won't lose too much coolant

Use a garden hose to flush out the core, in BOTH DIRECTIONS

You will be able to tell if its clogged up by the flow thru it, you can mix some CLR or Vinegar in warm water and pour it into the heater core
Wait 20min and flush again
Repeat as you see fit

A new heater core is not expensive and not hard to change in your year

Just for future reference you should swap heater hoses around at the firewall every 2 years or so, this will help to keep it cleaner by Back flushing it while driving
Heater cores have no direction of flow, there is no assigned IN and OUT, YOU assign the direction when you hook up the hoses

 

[Texican65]

After engine is cooled down remove the heater hoses at the firewall, you won't loose too much coolant

Use a garden hose to flush out the core, in BOTH DIRECTIONS

You will be able to tell if its clogged up by the flow thru it, you can mix some CLR or Vinegar in warm water and pour it into the heater core
Wait 20min and flush again
Repeat as you see fit

A new heater core is not expensive and not hard to change in your year

Just for future reference you should swap heater hose around at the firewall every 2 years or so, this will help to keep it cleaner by Back flushing it while driving
Heater cores have no direction of flow, there is no assigned IN and OUT, YOU assign the direction when you hook up the hoses

WOW! Now that is some GOOD info! Thanks very much Ron. I’ll try all of that directly! I had no idea about the core being “non directional”.

Dow

 

[Texican65]

Well...I gave the core the ol’ garden hose flush. I didn’t notice it being clogged on either end...both pipes had a steady gush of water.

Maybe I’ll just drain and flush the whole system, install a new core and thermostat and keep my fingers crossed. $40 for a new core...and as stated before...seems pretty easy.

 

[Texican65]

What’s the proper T-stat? And are different brands of cores better than others?

thanks,

Dow

 

[mnewman]

I believe stock is 192 or 195. Everyone on here says heat kills these engines so I just dropped a 180 in my B2. I think 185 might have been a better choice but I was in a hurry and that is what was available.

 

[franklin2]

How brown was the water coming out of the heater core? My 2.9 had chronic rust problems, and it would clog the heater core on a regular basis. I finally got it cleaned out and then the freeze plugs in the block started leaking. I could not even drain the radiator because it was plugged with sediment on the bottom. I hope yours is not a bad as mine was.

 

[Texican65]

Well...update for anybody that may care.

I flushed the cooling system, replaced the heater core $27...and replaced the thermostat, and SHAZAAM! She’s cranking out heat better than she has in 10 years. Very happy about it, and, it was super easy to change out the core.
Next time though, I’ll probably take the radiator off and have it brazed instead of dumping that stop leak crud in there...that was hard to get out.

I replaced the T-stat with a 192F...that’s what has been in there for as long as I’ve had the truck...many years. I’ve read differing opinions. Some say run cooler, others say run stock 192...that’s what the oil needs to lubricate properly...and since these 2.9’s are sticklers about oil...that’s what I went with...hopefully it works out... 232,650 miles now and still going.
Thanks again everybody,
Dow

 

[RonD]

Good work

Thanks for the update

Coolant(green) lasts for 2 years, remember to swap around heater hoses at the firewall to reverse flow direction when you change the coolant, that will help keep heater core cleaner

The 190-195degF thermostats help with MPG and yes the higher temp helps keep the oil cleaner, burns off water and fuel contaminants easier with that extra 10degF of heat
That's from an SAE(Society of Automotive Engineering) study back in the 1970s, thats when most auto makers started to switch from 180degF to 190+degF thermostats

 

[Eddo Rogue]

I did a whole thermostat chat, after finding so many differing opinions. Mine seems fine with the 195. Sometimes I switch to a 180 in the summer.

 

[franklin2]

Well...update for anybody that may care.

I flushed the cooling system, replaced the heater core $27...and replaced the thermostat, and SHAZAAM! She’s cranking out heat better than she has in 10 years. Very happy about it, and, it was super easy to change out the core.
Next time though, I’ll probably take the radiator off and have it brazed instead of dumping that stop leak crud in there...that was hard to get out.

I replaced the T-stat with a 192F...that’s what has been in there for as long as I’ve had the truck...many years. I’ve read differing opinions. Some say run cooler, others say run stock 192...that’s what the oil needs to lubricate properly...and since these 2.9’s are sticklers about oil...that’s what I went with...hopefully it works out... 232,650 miles now and still going.
Thanks again everybody,
Dow

On most radiators it's not worth getting them fixed. New ones are pretty cheap. Shop labor rates are very high.