|Posted on Monday, December 04, 2017 - 06:57 pm: ||
Some time ago, I posted about my 1999 Ford Ranger running too cold, and poor to no heat.
I found the problem. It had begun after I changed the thermostat because it was sticking.
I changed the thermostat 3 times. When I had it at a repair shop for some front end work, the mechanic said I had installed the wrong thermostat. (One from Autozone, one OEM motorcraft, and a Stant from NAPA). He installed a 4th one. didn't fix it. Changed the sensor, didn't fix it. Tested gauge, gauge is fine. I also installed a new radiator while I had it apart. The engine never ran hot, lost coolant or showed any problem other than the described symptoms.
Another repair stop, while replacing a water pump, changed it again, didn't fix it. Wanted to keep the truck to investigate. Took it home and told myself I would live with it.
Now cold weather is coming. I order a new thermostat housing and thermostat, thinking the plastic housing may be warped. Installed it with yet another thermostat. didn't fix it. Someone else suggested the fan clutch was sticking. Replaced it, didn't fix it.
I had followed the manual every time I worked on it, and figured the repair shops had too, and it still wasn't fixed.
I checked the operation of all the actuators, doors, etc in the dash, all good, including the infamous blend door.
Then it hit me. The sensor wasn't sensing because coolant was not going past it. The heat wasn't working because coolant wasn't going thru the core. That developed into: I think It has an air lock, but how after so many times following the book on burping the system?
I fabricated and installed bleed ports on both heater hoses and the upper radiator hose with schrader valves in them, took three old refrigeration gauge hoses, hooked them to the bleeds, submerged the ends in water so it could not suck air back in.
Cranked it, and operated the new heater control valve I also replaced because the old one was old (examination showed there wasn't anything wrong with the old one). The heater valve has four hoses. It either bypasses the heater core, or allows water thru it. I kept at it until no more bubbles came out of any of the hoses.
After I finished bleeding the system, I walked around and checked the gauge. Now it was running at normal temp. Turned on the heater and now the heat works!
All from air in the system. How in the world they purged the air when they built it, I haven't a clue. Now the heat works great, but there is that faint smell of glycol that says the heater core is seeping.
A new core and a fun day of "remove the dash assembly, and I will have that sucker licked!
|Posted on Monday, December 04, 2017 - 07:52 pm: ||
I wouldn't lick it if I were you. Glycol may smell like maple syrup, but it doesn't taste very good.
And it'll sure keep you regular.
|Posted on Monday, December 04, 2017 - 09:25 pm: ||
Or dump a bottle of Bars Leaks in the radiator and Bob’s your Uncle. The hell with ripping the dash out!
BTW- What engine is it? We had a 70-something Pinto with a 2.3L 4 cylinder and a similar issue. We later sold the car to my brother-in-law. He finally figured out that the issue was that the thermostat wasn’t “clamped” between the housing and the engine like on most vehicles. The thermostat needed to be pushed up into the neck to work correctly. Apparently the water pressure held it in position. Once that was done, it worked fine. Even the original factory thermostat was installed incorrectly.
|Posted on Tuesday, December 05, 2017 - 12:08 am: ||
Sounds like my 95 Z-28.
Heater hoses have bleeder valves and it helps to have a rubber chicken when bleeding.
Royal PITA but works fine after all the proper incantations.
|Posted on Tuesday, December 05, 2017 - 12:46 am: ||
The engine is a 2.5, and at 205,000 miles still does not use a quart of oil between changes. The funny thing is I have owned 5 different Jeep XJs and THEY are supposed to be hard to bleed air from the system. Never had a problem with any of them.
The 2.5 uses a thermostat with "legs" that hold it in position. They even have adhesive to hold them in place in the housing when you put it together. You peel n stick it in place, handy. And the housing is sealed with an o-ring so nothing gets out of place.
It also has had an engine code from some sort of EGR thingy that no one has fixed. I bought a Bluetooth dongle that reads code and has real time sensor info I am going to use to figure it out.
I am feeling up to working on it lately after a long time of health problems. Good therapy, too.
|Posted on Tuesday, December 05, 2017 - 09:58 am: ||
Damn that's a hell of a workout for sure!
My dad told me that the Renault "LeCar" cooling system had high spots and
the only way you could burp them out was to jack the front of the car up like 30 degrees.
He was an auto body guy in the '70s.
French = garbage
Saab = great deal of respect
American economy cars = "were they even trying?"
He still has these prejudices to this day.
It's pretty funny.
|Posted on Sunday, December 10, 2017 - 11:37 am: ||
From what I have seen the factory fills them under pressure. The rest of us pour in using gravity.
Many times on a variety of vehicles, I have jacked and burped cooling systems.
Sometimes the heater core isolates itself from the circulation and burping process altogether with its air bubble that is protected by the length of the heater hoses. The pressure to get coolant through the core is stopped by both hoses being pressurized at the same time.
Start the engine, poor the coolant in the uppermost heater core hose at it's furthest point from the core, before filling the radiator. Poor your coolant in through this hose held above the highest point. When the coolant flows out the port for the heater hose stuff the hose on quickly and immediately finish filling the radiator. Run it through several cycles of thermostat openings with the radiator cap off.
|Posted on Sunday, December 10, 2017 - 12:26 pm: ||
I thought the factory method was to pull a vacuum on the system while it's empty, then let the vacuum pull in the coolant. At least I've seen it done that way in shops. Not quite the stuff most shade tree mechanics can easily duplicate, but if you have a vacuum pump, it's not exactly rocket surgery. Shade tree method for many cars is to jack up the front as high as possible, and squeeze hoses to burp out air. I may not work well for all cars though.
|Posted on Sunday, December 10, 2017 - 01:16 pm: ||
My buddy's Ford Ranger needed a water pump so he brought it over and we changed it. THANKS FORD FOR FORCING US TO REMOVE THE AC COMPRESSOR JUST TO GET TO THE LAST BOLT YOU ENGINEERING GENIUSES!! We finally got it back together and we too had a hell of a time getting the air out. We thought maybe we had a cracked head since air seemingly kept getting in the system. He ended up pouring in some STOP LEAK and kept driving it and adding coolant. After it sat for a week he drove it again and it's been fine ever since. So I don't know if if the STOP LEAK worked for if we finally got the air out. His problem was over heating or was it just steam hitting the sensor? It was the V6 engine so a different animal.
|Posted on Sunday, December 10, 2017 - 03:34 pm: ||
..sifo...ding ding ding....what we use to do to refill cooling systems after doing any work on them....gets pretty much all air cavities out when a vacuum is applied to a cooling system.Works great....just have to let it cycle after the initial run after one is done to make sure all is working scopacetic...gauge needle where it should be,heating operations working right and i would slightly overfill the overflow bottle/tank(if applicable) so when the cooling system stabilizes... the level will sort itself out....then when cooled down...recheck the proper level and top of if necessary.....those devices that attach to the cooling system use air from a air compressor at shops...or if one has one at home...bingo..makes life so so much easier ...something i'm eventually going to have to invest in for when it comes time to do a drain and fill on both me and my wife's vehicles...thermostats are low in the blocks/engine as opposed to many that are up near the top..even more critical to do it that way....can have some negative effects if one doesn't get rid of all air cavities/pockets.....LT