Weird AC/Heat Problem

[max93]

Hello When I first got the LS a few months ago the heat didn't work. At that time, I did the HVAC self test and received a code. I can't remember and didn't pay it much mind because I wasn't worried about the heat. Fast forward, I turned the A/C on and it works well...until it overheats. I found this thread (http://www.lincolnvscadillac.com/forum/showthread.php?41319-01-LS-Overheating-(only-when-A-C-is-on-)) and took the cap off and ran it with the heat on. The heat blew hot (when it didn't work before) and I let it run for about 30 minutes. The fluid level stayed the same. I tried the AC to see what it would do with the cap off and it worked with no problem...never overheated. When I put the cap back on the heat didn't work well and the AC overheated. I googled and searched a lot of links on here and wasn't able to find the exact thing duplicated.

I read that the fan should kick in to a higher mode when the AC is on, but I can't SEE the fan. I have looked and I can't find it. I did the self test with the defrost and off again and all lights came on (which from I read on here indicated no error?).

Is there a fuse or relay that may be causing this? All fluid levels are good to go.

Any help or advice is appreciated. Thanks!

 

[joegr]

What do you mean by "AC overheated?" I assume that you mean the engine overheats?
What year is your LS and is it the V6 or the V8? These details make a difference.

No offense, but if you can't find the engine cooling fan, then you're not going to be the one solving this issue.
I'm going to guess (as your symptoms support it) that you have the typical cooling system plastic parts failing issue.

 

[max93]

What do you mean by "AC overheated?" I assume that you mean the engine overheats?
What year is your LS and is it the V6 or the V8? These details make a difference.

No offense, but if you can't find the engine cooling fan, then you're not going to be the one solving this issue.
I'm going to guess (as your symptoms support it) that you have the typical cooling system plastic parts failing issue.

No offense taken! I already know I am not qualified. It is an 02 V6. Yes, the engine overheats. If there are known things that can be done (fuses, relays...stuff like that) I can do I will. I can gather parts and things like that for when my mechanic comes back in to town. He is already growling at me because of the fan...he isn't the nicest man but he knows his stuff...I just want to be prepared.

By plastic parts, you mean the degas tank?

 

[fudge12]

Degas bottle, cap, all coolant hoses and such. Basically any plastic coolant components that are outside the engine.

Do you hear coolant boiling when the car is at normal temp/overheating? If you do, it's almost certain you have failed cooling components. The degas bottle is the first suspect.

 

[joegr]

No. there are no fuses or relays for you to check for this problem. You having the gen I V6, does make some difference. Now, the hydraulic cooling fan is a good suspect for your problems too.

 

[max93]

By "fan" they're referring to the engine cooling fan. You'll know when it's on as you'll hear it when it kicks on. What year and engine do you have? The v6 you'll have to stand and bend over from the driver side of the engine bay and look between plastic intake. You'll get a good look of the fan from there.

Is your coolant boiling with the cap on? Close it, run the a/c and bring it up to normal temp and listen for any boiling sounds.

It is an 02 V6. The coolant does boil with the cap on. I figured that was the fan, I just wasn't seeing it. The shop that did the basic diagnostics said that it was coming on, but they put their hand in the front of the car by the grill.

 

[joegr]

It is an 02 V6. The coolant does boil with the cap on. I figured that was the fan, I just wasn't seeing it. The shop that did the basic diagnostics said that it was coming on, but they put their hand in the front of the car by the grill.

Start the car cold, with the AC off. Listen and feel the airflow at the grill.
Now, turn the AC on. The fan should get noticeably louder and the airflow should be greater. If not, then the hydraulic fan system has a problem. Maybe the actuator, or maybe something else. It can be a difficult system to troubleshoot. The dealer's solutions were to just replace it all, at thousands of dollars. Check the hydraulic fan reservoir. See what condition the fluid is in. If it is milky, someone may have added water to it instead of ATF.

 

[max93]

No. there are no fuses or relays for you to check for this problem. You having the gen I V6, does make some difference. Now, the hydraulic cooling fan is a good suspect for your problems too.

Thank you for that. I found the relay diagram and was going to swap the ones relating to AC but now I will not. I based that on this (I am not sure if it does or not, but 2000 to 2002 Lincoln LS has a hydraulic pump driven fan, and there is a relay, under the hood in the fuse/relay box on the driver's side, just behind the battery. The lid of the box has the diagram of the fuses/relays. In this look at the part labeled C107 and c 105...from a google search)

I have heard that the fan is an issue in these cars.

 

[max93]

Start the car cold, with the AC off. Listen and feel the airflow at the grill.
Now, turn the AC on. The fan should get noticeably louder and the airflow should be greater. If not, then the hydraulic fan system has a problem. Maybe the actuator, or maybe something else. It can be a difficult system to troubleshoot. The dealer's solutions were to just replace it all, at thousands of dollars. Check the hydraulic fan reservoir. See what condition the fluid is in. If it is milky, someone may have added water to it instead of ATF.

This I can do! The fluid is not milky, I checked it yesterday. I am going to try this at lunch time. I appreciate your help!

 

[LS4me]

Thank you for that. I found the relay diagram and was going to swap the ones relating to AC but now I will not. I based that on this (I am not sure if it does or not, but 2000 to 2002 Lincoln LS has a hydraulic pump driven fan, and there is a relay, under the hood in the fuse/relay box on the driver's side, just behind the battery. The lid of the box has the diagram of the fuses/relays. In this look at the part labeled C107 and c 105...from a google search)
I have heard that the fan is an issue in these cars.

PSSSSSSSTTTTT...... The battery is in the trunk, down by the spare tire......

 

[max93]

PSSSSSSSTTTTT...... The battery is in the trunk, down by the spare tire......

I found that the same time I noticed I could fit about 6 bodies in the trunk if need be LOL

 

[max93]

Start the car cold, with the AC off. Listen and feel the airflow at the grill.
Now, turn the AC on. The fan should get noticeably louder and the airflow should be greater. If not, then the hydraulic fan system has a problem. Maybe the actuator, or maybe something else. It can be a difficult system to troubleshoot. The dealer's solutions were to just replace it all, at thousands of dollars. Check the hydraulic fan reservoir. See what condition the fluid is in. If it is milky, someone may have added water to it instead of ATF.

I did this. I didn't feel any airflow when I started the car and didn't notice a difference when I turned on the AC. That's puzzling because the shop told me the fan was working but I cannot see it spin or feel it. Thank you for your help!

 

[max93]

Degas bottle, cap, all coolant hoses and such. Basically any plastic coolant components that are outside the engine.

Do you hear coolant boiling when the car is at normal temp/overheating? If you do, it's almost certain you have failed cooling components. The degas bottle is the first suspect.

I missed this reply. Thank you for that! I will start pricing them! To answer your question, no, I do not hear the boiling sound at normal temperature. Only when it overheats, and that has only happened when I ran the a/c.

 

[joegr]

I think that your fan isn't working correctly, and maybe not at all. That was probably the origin of your problems, but the overheating may have been the last straw for the degas bottle and maybe a few other parts.

 

[max93]

I think that your fan isn't working correctly, and maybe not at all. That was probably the origin of your problems, but the overheating may have been the last straw for the degas bottle and maybe a few other parts.

Thank you. When I ran the car with the degas bottle cap off, shouldn't some of the fluid been sucked inside? The amount of fluid never changed. I was able to fix my central a/c unit at home, but couldn't find the fan in the car. Today is not my day!! lol Appreciate your help!

 

[joegr]

Thank you. When I ran the car with the degas bottle cap off, shouldn't some of the fluid been sucked inside? The amount of fluid never changed. ...

No. Actually, it should rise slightly (cap on or off) as the engine heats up, and then lower slightly as it cools back down. There's no real circulation in the degas bottle. It's there to buffer the amount of coolant as it expands and contracts due to temperature, and to remove gas (air and steam) from the coolant.

Loosening the cap is a trick that I have used before to be able to keep going while I was waiting for the parts to arrive. It keeps the system for pressurizing, so it reduces the rate of any leaks and also greatly reduces the amount of air that gets sucked into the cooling system through those leaks when the engine cools down.

 

[max93]

No. Actually, it should rise slightly (cap on or off) as the engine heats up, and then lower slightly as it cools back down. There's no real circulation in the degas bottle. It's there to buffer the amount of coolant as it expands and contracts due to temperature, and to remove gas (air and steam) from the coolant.

Loosening the cap is a trick that I have used before to be able to keep going while I was waiting for the parts to arrive. It keeps the system for pressurizing, so it reduces the rate of any leaks and also greatly reduces the amount of air that gets sucked into the cooling system through those leaks when the engine cools down.

Interesting. I may try that since we are having some 90+ degree days in MD right now. Between your help with the tie rod toe lateral link...(why can't they be called one thing!), and this...I have an idea of what I need to get now. Thank you again!

 

[milehighmikey]

Not sure about the V8, but the V6 seems to pass water through the degas bottle constantly, and it is fed by the lines that circulate water through the throttle body.

I had this same problem and it turned out to be the solenoid valve on the fan's hydraulic pump. A simple fix that has lasted the past 4 years for me with no problem. My fan was turning, but nowhere near what is needed to cool the condenser and radiator's load. I found out the hard way, after changing my radiator needlessly.

 

[max93]

Not sure about the V8, but the V6 seems to pass water through the degas bottle constantly, and it is fed by the lines that circulate water through the throttle body.

I had this same problem and it turned out to be the solenoid valve on the fan's hydraulic pump. A simple fix that has lasted the past 4 years for me with no problem. My fan was turning, but nowhere near what is needed to cool the condenser and radiator's load. I found out the hard way, after changing my radiator needlessly.

Thanks!! I did see that the fan is indeed turning. I will make note of that and perhaps he can change that out first.

 

[joegr]

The solenoid valve is on the fan motor, not the pump.
Yes, there is some circulation from the engine vent line to the degas, but it's not like all the coolant circulates through the degas, unlike the fan reservoir and the power steering reservoir.

 

[max93]

Ok, I'm back. I haven't really fooled with the a/c or had my mechanic look at it yet. I took the chance and turned my a/c on and drove it and it didn't overheat. I drove further and it still didn't overheat. Later, I turned the heat on and it blew hot air. Could the thermostat been stuck open and 'unstuck'? Is this completely weird? This car is just so puzzling to me!

 

[joegr]

Almost anything is possible, but that is very unlikely.

 

[max93]

Almost anything is possible, but that is very unlikely.

That is what I was thinking but the whole thing doesn't make sense. No heat, and the ac causes engine overheating and then I have heat and no overheating with the ac on. LOL Thank you!

 

[Penelope Garcia]

Name change (logged in with FB when I had an emergency last night and couldn't remember my password)! Mechanic finally looked at this and wants to replace the fan sensor? We shall see.

 

[Penelope Garcia]

Ok, I'm back. I haven't really fooled with the a/c or had my mechanic look at it yet. I took the chance and turned my a/c on and drove it and it didn't overheat. I drove further and it still didn't overheat. Later, I turned the heat on and it blew hot air. Could the thermostat been stuck open and 'unstuck'? Is this completely weird? This car is just so puzzling to me!

Being that hard head that I am, I have ordered various parts, but haven't had them put on yet. I was looking for all of the plastic cooling parts, and the only plastic part that I see is the degas reservoir? That being said, I just broke down and ordered a fan pump assembly. When we get to swapping out the parts, we have a thermostat, water pump, some fan pump sensor, and the fan/motor.

My question is about the bleeding the air out the system.

The first time that I did it, I didn't have the car on an incline. I ran the heat on full blast and watched the coolant level (cap off) and the fluid level never changed at all. Not even when I shut the car off.

I gave it another shot yesterday. This time I parked it on an incline. While the heat was on full blast I squeezed the upper radiator hose multiple times like someone suggested. We did this for about 20 minutes or so. The fluid level never changed (up and down a bit with the squeezes) but nothing significant. This time, when I cut the car off (didn't put the cap on before I did it), the coolant bubbled up and out of the reservoir. When it cooled down I added more coolant because it was low at that point.

Is that what is supposed to happen when you bleed the air?

Thanks!!