Another overheating LS thread

Lincoln LS

  1. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    Yes...another overheating thread. I have used this website every now and again for years. I finally became a member because for once I couldn't find the info I need. Please and thank you to anyone that can help. I'll try to keep it as short as possible but here is everything that I believe could possibly be relevant.

    2005 LS V8 AC dies. I am told AC compressor but did not get it done. 2 weeks later car overheats. Shop ran it for an hour and said it was fine, $100. It wasn't. I found that the thermostat cap wasn't on correctly and ended up putting on a new thermostat and cap myself. Still overheating. I took it to a different shop who say they can't find anything wrong but suspect head gasket. They then later say it passed their hydrocarbon test but upon looking in with a camera there is "slight evidence" that coolant had been in the cylinder. I took car back and it's basically sat in the driveway for well over a year. I start it up at least every couple of months and I eventually I noticed it didn't overheat with the heater on. As soon as I turned it off though the car immediately began to overheat. Heat back on, car cool again. I then drove it around quite aggressively for about an hour with the heat on full blast and I could not get it to overheat unless I flipped the heater off.

    What I think is probably NOT the problem and why:
    -Head gasket. Car has no smoke of any color coming out of exhaust. Car also does not lose coolant(at least not in approximately 200 miles).
    -Air in system. This ain't my first rodeo with this girl. I've had air in it before from a little to a lot, I know what it sounds like. I've also gotten good at the bleeding procedure and am pretty positive there is no air and no noticeable leaks.
    -Thermostat, hoses, degas bottle. These are all less than a few years old and again, no leaks.
    -Radiator fans, electric cooling fan. I can hear/feel them.

    What I think IS possibly the problem and why:
    -DCCV. It's basically the only thing pertaining to the cooling system that I haven't replaced. Also maybe the diag for the AC compressor was actually from this. Maybe not. I don't know much about how the DCCV works. I don't know if the sides blow different temperatures either. I never tried and it only blows warm to hot anyway.
    -Water Pump. I replaced it a few years ago but I know the plastic impeller can break and stop spinning with the pulley or whatever. Also the coolant doesn't necessarily seem like it's flowing but I've really only seen it flow when the car has been messed up and had tons of air in it. Basically, the degas bottle doesn't drain to bottom when tstat opens which may or may not be normal, I don't know. I've never looked at that specifically very closely when it's running right.
    -Radiator. A few years ago when nearly everything in the cooling system got replaced my oil cooler was on that list. There was lots of oil in the system until it all got replaced. The radiator was replaced in this same ordeal of repairs about a month later. I was told after all was said and done that there was still some oil in it because they didn't want to ruin their flushing machine and some air because they couldn't get it all bled. The air I believe did cost me a thermostat later on(I'm on #4) from which I've learned the lesson but the oil never caused me a problem. The coolant was slightly murky until the next repair and next batch of coolant but I never saw it after that. However maybe it could've clogged up my radiator fins over time since they're very small. Also could've clogged DCCV
    -2nd water pump? I've seen that these cars have a second auxiliary water pump and I haven't replaced that. I don't see how this would cause my symptoms though.


    To keep my life out of it I'll just say that I currently have no car and need to get this one running. I also don't have money to play guessing games. I have a diesel mechanic cousin who can probably help me diagnose if I know what I'm looking for.

    Things I would like to know:
    1. WTF is wrong with my car? lol
    2. How can I test the DCCV? What temps from what hoses or how?
    3. What temperatures from which hoses on the radiator would indicate a healthy radiator for this car? Or how else can the radiator be tested?
    4. Is there another way to tell if the water pump is bad without taking it off and having to refill coolant and bleed? Will do that if necessary obviously but it would be cool if you could tell it was bad by how freely it spins or something.
    5. WTF is wrong with my car? And if anyone suggests head gasket I'll shove your head in a gasket. Just kidding. But seriously please help me.


    -Big Al
    KC, MO
    2005 Lincoln LS V8 SPORT
     
  2. joegr

    joegr Dedicated LVC Member

    Messages:
    19,521
    Likes Received:
    1,420
    Joined:
    Dec 10, 2005
    Location:
    Gulfport
    Please search again, because all this has been covered over and over again.

    A. I could never "hear" the air in the system.
    B. You have only one engine cooling fan. How can you really know it is working okay if you haven't even seen it enough to know there is just one? Anyway, such failures are indeed rare.
    C. The level in the degas bottle should go up a little when the engine is warmed up, and down a little when it is completely cooled off. It should stay between the hot and cool fill lines. It does not empty. The level does not change when the thermostat opens/closes.

    1. Same as 99% of the other gen 2s when they overheat. You have to replace every single plastic part. You have to use OEM (radiator is the exception). You symptoms are most suggestive of using an aftermarket thermostat, but don't forget the other parts too. Yes, the radiator could be clogged.
    2. Set climate control to 60 or 65. Do you get non-heated air when you first start the car with a cold engine? Does the air start to heat up when the temperature gauge starts rising? Does it get to be very hot coming out once the engine has reached temperature? Yes, then bad DCCV.
    3. Once the thermostat opens, the upper hose should be 190 to 210 F. The bottom hose should be a lot less, depends on your outdoor temperature. This really doesn't tell you much, since you won't know how much flow there is, other than if the lower hose is really cool, it's not flowing.
    4. Not so much. The factory pump is very durable and should go over 200K miles. Aftermarket pumps are not nearly as good.
    5. Same thing(s) as the other overheating LSes. Microcracks in the plastic letting air in, failed thermostats (plastic holding the metal parts cracks), or you used the Dorman/aftermarket thermostat and/or cross over assembly.
     
  3. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    Thank you. I've looked on this site for a long time and found nothing that matched my exact symptoms. I say I can't hear air in the system anymore because in the past when I've had known air in the lines I've usually heard it bubbling and flowing once I turned the car off. This was before I learned the specific bleeding procedure for this engine and when I did less work on it myself. I guess there could still be some in there. But whenever everything worked and there was just air in the lines, it ran fine for nearly a year until the thermostat blew a hole again. Since it's most recent thermostat though, there has been no change in the fluid level and I do not hear air bubbles or see them bubbling in the degas. The degas does exactly as you say so that is good. I thought there were 2 fans because I always read about the electric cooling fans on the gen 2 vs the hydraulic fans on the gen 1. I thought this was a 2nd fan because of the jet engine like noise the fans make when the engine gets hot, thought that was a separate fan making that noise. I don't think every part I've used was the OEM part but about 20k miles ago I had a shop replace the thermostat, the inlet pipe behind it, the water pump, every hose including the one in the intake manifold or wherever and the hard plastic tpipe in front, the radiator and the oil cooler. I replaced all of that because it all started exploding one by one. I've never replaced the DCCV valve though. My car has 177k but the water pump and the rest was replaced at 150k. I may have made a mistake and cheaped out on the water pump and I've seen a video of the water pump on this car having the impeller become unresponsive to its pulley. I don't see why my car would stop overheating with the heater turned on if the water pump was bad though. I do believe the air heats up as the car does which is normal but I'll see if it does it like you say at 60-65 degrees. If the car stops overheating with the heater on, does that mean it's only getting cooled by what flows through the heater core and therefore a clogged radiator? Or is this something that the DCCV could cause?
     
  4. joegr

    joegr Dedicated LVC Member

    Messages:
    19,521
    Likes Received:
    1,420
    Joined:
    Dec 10, 2005
    Location:
    Gulfport
    The heater cores bypass the thermostat, so your symptoms would support it being a clogged radiator or a failed/failing thermostat. Several here have had such problems with the aftermarket thermostats. They are popular because they are cheaper and include all the parts already assembled in the housing, unlike the Ford parts. Post a picture of (with the engine cover off), and we can tell if it is Ford or aftermarket. You could also test for it being the thermostat by temporarily removing the metal thermostat parts and seeing if the overheating stops and the engine runs too cold.

    Note too that the heater has its own water pump, so it also partly (not entirely) bypasses the water pump.
     
  5. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    I'm pretty sure it has an OEM thermostat or at least a functioning one. I had a Dorman thermostat be defective on me right out of the box, it never opened. So
    Test the radiator temperature on each end. 180-210 going in but what about coming out? Should it drop 20 degrees or 100 degrees or how much exactly?
    Test water pump by taking it off and make sure its functioning properly.
    So for the DCCV I would test that by seeing if the air goes from cold to hot as the engine temperature rises if its set to cold? Is this a solid indicator and could my diagnosis of toasted AC compressor play into this test?
     
  6. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    I re-read what you said above and understand what you mean about radiator temperatures not really indicating flow. It might help a bit though if I measure them with the heater on and off, overheating and not overheating. Maybe. What would be the best way to diagnose a clogged radiator?
     
  7. joegr

    joegr Dedicated LVC Member

    Messages:
    19,521
    Likes Received:
    1,420
    Joined:
    Dec 10, 2005
    Location:
    Gulfport
    Some sort of external flow test rig.
     
  8. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    And if the air goes from cold to hot when set to cold, how can I further be sure it's the DCCV? I kind of know where it's at. Is there any way to tell by measuring temperatures from it's hoses? I hate to sound like a dummy but it looks like it has one hose coming in and two going out, the 2 going out being one above the other or possibly next to each other. What should the temperature of these hoses be? Or is the test you spoke of good enough for me to go ahead and change it out?
     
  9. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    Sorry it actually appears that there's possibly 4-6 connections and I really don't know what each one is. How can I 100% diagnose this though? You've been amazing so far, thank you
     
  10. joegr

    joegr Dedicated LVC Member

    Messages:
    19,521
    Likes Received:
    1,420
    Joined:
    Dec 10, 2005
    Location:
    Gulfport
    If you have a 2005 LS V8, then the DCCV is this one.
    hqdefault.jpg
    There is one in port, and two out ports (one for the driver's side heater core, and one for the passenger side).

    There are no temperatures to measure. Both valves should be closed if you aren't asking for heat. If you are getting heat, then one or both are open or at least partly open. There can be electrical problems that cause this, such as the valve being disconnected or a wire cut or shorted. There are full tests to verify this.

    2006 Lincoln LS Workshop Manual
     
  11. Big Al 241

    Big Al 241 New LVC Member

    Messages:
    7
    Likes Received:
    0
    Joined:
    Sep 22, 2019
    Location:
    KCMO
    Thank you much Joe. I believe I know what to look for now. I will check back in with the final fix.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.