The dreaded "No Heat"

[LibertyMan02]

Ok, I thought I could get by since I have heated seats, but at 16 deg. during the day, I can't deal with it much longer. When I bought the jeep used, I checked AC and heat and both worked flawless. SO I drove it for a little while when one day, the heat was lagging badly. By the time I had driven it 30 min, it was finally hot. Then when the timing chain guides broke, I went through that mess with a fresh coolant flush and new coolant. Thermostat was good still. Very cruddy coolant and full of rust due to the spring rusting out on one of the rad hoses. PO claimed he replaced the Rad and water pump. Pump was in good shape. Did a complete flush and got a tone of crud out. Also did a revers flush on the heater core and got decent flow out of it. Deep cleaned the reservoir. The old coolant seemed very rich on water and was barely sticky when it poured over my hand. Engine ran and still does, in the norm zone. Now, the heat won't even blow no matter how long you run it. Since I also lost 1 and 2 fan speeds(strangely at the same time all the other stuff happened), It gave me some ideas. What happens is this: With the engine at running temp, I'll turn the heat on and, for 3 seconds, it will blow nice and hot, then fade to barely lukewarm, mostly cold. Turn it off, and back on, and the same happens. Also, when I turn it to the defective fan speed so the blower doesn't work, turn it back to a running setting, it does the same thing. After the flush, I've had this annoying rushing water sound coming from the dash. Never did that before. Never smell coolant when inside. Fixed all hose connections so no leaks there. Nothing coming from the condenser drain. have to top off the coolant every now and then. Sometimes, the coolant level goes down when hot, then when cold, returns to normal. Oil was changed when the flush was done. No coolant there. Blend door seems to work as it should. Big writeup, but at least Y'all know what I've got. LOL Little help??

 

[CzarKJ]

ok sounds like you have a few issues going on that make it seem like one. The missing speeds could be blower motor resistor. Losing coolant? Gotta find the leak! Try the top left of the rad (battery side) first. Then lower hose and under the overflow tank. Though it seems you checked them all maybe hot something is expanding and opening just enough.

 

[LibertyMan02]

I have gone over all like some 5 times, both hot and cold. New info just discovered. May or may not be related. Recently, the check engine light has been coming on. My bro had a program and was able to get the code. Looked it up just now and its, Engine cold too long! Weird.

 

[ltd02]

Are you sure the T-stat is okay?

I had crappy heat when my Rad cap wasn't sealing too.

The gurgling you describe sounds like you may have some air in there. Might be slowly working its way out which is why you have to add coolant every now and then.

Just some things I've had happen to me. These systems are usually self "burping"

 

[CzarKJ]

Are you sure the T-stat is okay?

I had crappy heat when my Rad cap wasn't sealing too.

The gurgling you describe sounds like you may have some air in there. Might be slowly working its way out which is why you have to add coolant every now and then.

Just some things I've had happen to me. These systems are usually self "burping"

Good point actually! Was just thinking the T-stat may be upside down? Bleed hole on top?

 

[LibertyMan02]

My Dad has worked on cars for years and things like checking a TS is old hat to him. When pulled, it was closed with a cold engine, so heat should be hot if it was the thermo. Made sure it was in the right way as I heard it was easy to get it wrong. Pretty sure my rad cap is good as the system does pressurize. Ask how I know. LOL

 

[renegade 04]

If it is losing coolant try feeling the bottom of the upper radiator hose where it meets the engine block because that is where mine was leaking from.

 

[ltd02]

You are using HOAT coolant right? Mine usually feels slippery not sticky. Still leaning toward some air in there and/or the heater core is not flowing well enough.

 

[belvedere]

When pulled, it was closed with a cold engine, so heat should be hot if it was the thermo.

That doesn't mean that it opens at the proper temp. If it opens too soon, there won't be much heat. If I was going to all that work, it sure would have gotten a new OEM 'stat.

That said, I agree with the guy who said it sounds like air in the system.

 

[LibertyTC]

Question 1= Is it a Mopar thermostat in there that comes with a bled hole on Top ?
Q2= Did you use the bleed hex screw to get the air out after it was hot?
(rushing sound or gurgling is probably trapped air in system)
Q3 with a complete water flush, you absolutely must use 100% full strength HOAT.
Not a 50-50 premixed, and so using an antifreeze tester, what is the current coolant reading -40 -50 or..??

 

[jeepontruckin]

I recently went theough hell with my coling system also. Put in 2 different thermostats. Ii did the boiling water test on the 2nd one 1st to make sure it was operating. My cooling system would absolutely not circulate on its own after a flush no matter how i tried to bleed it. I ended up removing the upper hose and filling the block up with coolant through a funnel as well as the radiator. Then did the bleeding process. Thats what worked for me.

 

[draperjojo]

Your fan speeds not working are probably the resistor block behind the glove box, as was mentioned earlier. You will likely go through several because they are light duty, but there is one from Chrysler that fits one of the cars that is a heavier duty version, and a drop in fit. Search for it in the forums, it's an easy change out.

When I install new thermostats, I drill a hole in the top of the tstat with the smallest drill bit I have, to bleed off the air AND I also use that bleed off screw. The tiny hole allows the air to bleed off while maintaining the coolant in the engine until it heats up the tstat and opens the circuit to the radiator.

 

[LibertyMan02]

Yes, the thermo has a little hole in it. I have no clue what the coolant is. me and my dad have used it in all our families cars, as well as the heavy machinery in my dads business. We mixed it our selves as 50/50. It's pink in color. I have no clue what HOAT is. it was my only driver and we were already a month on the job. It's what he told me to put in it! LOL It's sticky/slimy like most coolant is. I can always drain it and flush again in a weekend if I have too. Just not at 16 deg! I heard about the resistor. On my list. Just read about the bleed screw and will try all this stuff mentioned.

 

[uss2defiant]

The bleeder hole on the T-stat needs to be on the top when installed.

hybrid organic acid technology (HOAT)

 

[LibertyMan02]

It was. Made sure I got it right. A quick review in my factory shop manual, it says this, "(2) .Fill system using a 50/50 mixture of ethyleneglycol
antifreeze and low mineral content water.Fill
pressure bottle to service line.and install cap." It does no specify.

 

[ltd02]

In the fluids section of your FSM you will find more information. HOAT coolant is ethylene glycol based. The HOAT are special additives.

The use of aluminum cylinder blocks, cylinder heads, and water pumps requires special corrosion protection. Mopar Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MS-9769), or the equivalent ethylene glycol base coolant with organic corrosion inhibitors (called HOAT, for Hybrid Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% Ethylene Glycol and 50% distilled water to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.
CAUTION: Mopar Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MS-9769) may not be mixed with any other type of antifreeze. Mixing of coolants other than specified (non-HOAT or other HOAT), may result in engine damage that may not be covered under the new vehicle warranty, and decreased corrosion protection.

 

[LibertyTC]

Yes, the thermo has a little hole in it. I have no clue what the coolant is. me and my dad have used it in all our families cars, as well as the heavy machinery in my dads business. We mixed it our selves as 50/50. It's pink in color. I have no clue what HOAT is. it was my only driver and we were already a month on the job. It's what he told me to put in it! LOL It's sticky/slimy like most coolant is. I can always drain it and flush again in a weekend if I have too. Just not at 16 deg! I heard about the resistor. On my list. Just read about the bleed screw and will try all this stuff mentioned.

You absolutely have the wrong coolant in there =EEK !
Your waterpump has a plastic impeller and wont like the current antifreeze either.
You can drain/flush it all over again with water and use the Chrysler 100 % strength Hoat antifreeze, or use Zerek G05 only Link: Valvoline.com > Products > Zerex > Antifreeze Zerex > Zerex G-05
Or take it to the dealer and have them do the flush for you. They have the proper machine that removes all the old while installing the new HOAT.
I think I paid the dealer $129 for this and it should be done every 5 years or sooner.

 

[TwoBobsKJ]

It was. Made sure I got it right. A quick review in my factory shop manual, it says this, "(2) .Fill system using a 50/50 mixture of ethyleneglycol
antifreeze and low mineral content water.Fill
pressure bottle to service line.and install cap." It does no specify.

It does require HOAT coolant and the stuff you put in will sludge up as it corrodes the water pump impeller and other parts. Believe me, I also fought the folks on here who said use only HOAT and nothing else. Had my system flushed by a local shop that used "universal" antifreeze and soon after I had a radiator leak and a bad water pump. I tucked my tail between my legs, wrote a post telling everyone on here they were right, then got the system flushed and HOAT put in.

Bite the bullet and have the system flushed (yes, even go to the dealer. Their price is usually pretty good.) so you have the proper antifreeze in there. If you want to do it yourself you can find Zerex at NAPA or O'Reilly's. Buy the concentrate and mix it with distilled water.

Bob

 

[uss2defiant]

firestone has the correct coolant as well.

 

[LibertyMan02]

H'mm, Ok. Of course I am so tight on funds it ain't funny. Gonna have to save and hope for the best till I can get money to do the job. Will still check the things mentioned and see if it will work. EDIT Found it in the manual. Gonna have to get this fixed I guess. Aside from that, any other ideas on the no heat problem?