Been researching about heater issues. Looking for some ideas from the YJ gurus...
Bought the 95 w/ 2.5 in the summer. engine ran very cool. summer in Florida - that's a good thing.
Well - since it's FL, of course I have no top and only half doors. A little heat would be nice in the evenings on the feet.
OK -- as expected, the PO had no thermostat in the motor. Got the factory replacement 195 and installed. Radiator pretty nasty, but worked before so must flow ok. Flushed it out refilled.
After many attempts to burp out the air, I finally got it all, I think. Jeep now runs up to that 195/200 line which is good. But almost as soon as it does, the T-Stat must open all the way, and it cools right down to 150/160ish. I realize there may still be some air pocket causing this. (Stupid me forgot to 'clock' the T-Stat on installation. Not sure where the burp hole ended up) -- NOTE TO SELF--- READ FORUM FIRST!!!!!
Anyway - The real question, even at operating temperature, BOTH heater hoses are COLD. I've though about a clogged heater core, but wouldn't the hoses still be hot leading into it?
You said the radiator was nasty so its possible that some of that could have settled in the heater core and clogged it. When I flushed mine a while back my radiator was relatively clean but I still flushed a decent amound of crud from the heater core.
Try taking both of the hoses off that lead to the heater core and back flush it. Meaning run the water from the hose going to the intake back through the core to the hose for the front of the motor. The water normally flows from the water pump back through the heater core and then into the intake.
Just the pressure from a garden hose will be enough.
It might loosen up the crud in the core, or you might need to replace the core.
thanks guys. will give it a shot. funny that I slightly smell antifreeze now, but never did before I put a T-stat in it.
Then again - the PO only had water in it I think, so may not have smelled that anyway.
Once again -- if you own a YJ and aren't a member of this forum -- FOOLISH!!!
I did as discussed-- was clogged so bad that water would even go in the hose at first. Just sprayed back at me, even with hand around it.
After sealing gardenhose in there better and keeping at it - sure enough the blockage passed. Nasty crap came out for a while.
Buttoned up, and we have heat!
One little issue remaining - temp goes up to 195ish like it should, but cools back down to 150-160. and repeats! After test ride, came home shut down. Could hear the radiator cap 'weeping'. So I will replace that cap. Could that cause the temp fluctuation?
Definitely replace the cap, the fluctuation is most likely due to an air pocket hitting the gauge sender, probably need a "heat up cool down" cycle or two, topping off each time.
Well -- new cap was needed. stopped the weeping. However, the temp fluctuation didn't stop. I only had limited time, so perhaps as jloshotz suggested, a few cycles may be needed.
Of course now that the system is holding pressure, the old heater hose has started to leak some. Par for the course I assume.
I have a 88 YJ with the 2.5 and also live in Florida. My heat never worked, this year I decided to find out why. I pulled the cover off the fresh air intake and with the help of a shop vac sucked out what would equal to 3 nice squirrel nests. Then I pulled the air regulator box off (passengers side above floor) Cleaned all the crap out of this as well. Next like you I found no thermostat, so got the recommended 195*. Next came the flush, were I disconnected the hose from the thermostat that runs through the manifold. Then disconnected the side that exits the manifold, flushed it until water was clear and flowing smooth. Then I disconnected the return side of the side from the heater core at the thermostat. I placed the intake hose in a gallon jug and lowered it. Filled the return hose with flush and let it set for 30 min. I rigged my air hose to the return hose and started adding pressure. Seemed like it was never going to clear when boom the hose in the jug flew out and spewed nasty stinking rusty crap all over the place. I repeated the flushing 6 or 7 more time adding flush and letting it set before pure clean water cam running out. I drained the water, filled the core with 50/50, put new thermostat in, hooked all hoses back up topped the system off with 50/50 and I have good hot air when it’s cold outside. I think I could drive it without the top and stay warm…But this is Florida. And yes I flushed the radiator, and replaced the pressure cap
Firewalker -- I'm sure the others on here think us Florida guys are idiots talking about HEAT!! LOL!!!
Update - ever seen the pressure relief hose that goes from the Cap to the expansion(overflow) tank be clogged?? I have now. Unreal. Looked like cat crap when it finally came out via severe water pressure.
But -- it seemed to be the last bit of my issue. Drove all over yesterday to kids events, and all was well. I will say this though that when the heat is on full blast, the engine temp still drops some. I guess in reality, it is like adding an extra radiator.
A big plus of fixing this stuff, is the engine runs much smoother at operating temp than it did cold. Removed the hesitation for sure.
Question - are the plugs in the bottom of the radiator replaceable? One has a tiny little drop happening.
dman2721, after reading your post about the temp gauge I noticed my jeep does the same thing. Did not notice it before, must have always done that. When your talking about the plugs, are you referring o the cox valve that drains the radiator? I had my radiator rebuild at a cost of under 40 dollars.
Found a stock pic online -- the plug I am referring to is outlined in RED.
I have a slight drip coming from that one on mine. Wondering if it's something I can pull, and add a sealer to an reinstall.
Found a stock pic online -- the plug I am referring to is outlined in RED. I have a slight drip coming from that one on mine. Wondering if it's something I can pull, and add a sealer to an reinstall.
Those look a lot like where automatic transmission lines would connect to the radiators internal tranny cooler tank section. You may be able to carefully snug it up with a wrench, carefully being the key word if the end cap that it is installed in happens to be plastic. If in doubt, remove and inspect more carefully, or bring to a radiator shop
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