1999 TL overheating, not thermo
06-13-2009, 03:56 PM
#1
10th Gear
Thread Starter
1999 TL overheating, not thermo
Hey everybody,
I've got a 1999 TL that just started overheating. I replaced the thermostat today and it's still overheating. It does fine on the interstate, but in the city it will quickly get very hot, but I always stop before it gets too hot.
I started it up and paid attention to the fans after the thermostat replacement. The passenger side only comes on with the AC, which is how it is supposed to behave as I understand it.
The driver's side fan DOES NOT come on, even after I let the car get hot. I pulled the fan out and it spins freely, so the motor isn't locked up, but I don't know if it still works or not. Anybody know the voltage that the fan takes? I could just test that.
I also did some research and saw that the coolant temp sensor often goes, so I'm looking into replacing that. Anybody know what size socket you need to get that sensor out?
Thanks in advance for the help!
I've got a 1999 TL that just started overheating. I replaced the thermostat today and it's still overheating. It does fine on the interstate, but in the city it will quickly get very hot, but I always stop before it gets too hot.
I started it up and paid attention to the fans after the thermostat replacement. The passenger side only comes on with the AC, which is how it is supposed to behave as I understand it.
The driver's side fan DOES NOT come on, even after I let the car get hot. I pulled the fan out and it spins freely, so the motor isn't locked up, but I don't know if it still works or not. Anybody know the voltage that the fan takes? I could just test that.
I also did some research and saw that the coolant temp sensor often goes, so I'm looking into replacing that. Anybody know what size socket you need to get that sensor out?
Thanks in advance for the help!
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Jimiredd (07-23-2013)
06-13-2009, 04:51 PM
#3
check for power at the fan connection
replace fan temp sensor- you are correct
Be sure to bleed/burp the radiator after you did the thermostat
If there is any air in the system it will get stuck and fool the temp sensor!
Heater must be set to hot and there is a special procedure- not like normal cars-
the TL has a trick procedure- found in owner book
Since you are a new owner here is the free owner book with DIYs for all the basic stuff and the normal info on car systems
click your year then model - pdf file- download or read online
https://techinfo.honda.com/rjanisis/...01_OMANUAL.asp
That driver side fan had better come on as soon as the temp climbs to the middle!
Normal temp is a few ticks below middle
Do NOT run the ac while you have this problem- extra load will cause engine damage= blown head gasket
How many miles- was the water pump replaced at 105k miles?
How does the radiator look inside- and the coolant- good color or weak color
Did you use a honda thermostat from dealer?--
but check the air burping
If you buy a new sensor --hopefully its the same size socket/wrench--but sometimes not
replace fan temp sensor- you are correct
Be sure to bleed/burp the radiator after you did the thermostat
If there is any air in the system it will get stuck and fool the temp sensor!
Heater must be set to hot and there is a special procedure- not like normal cars-
the TL has a trick procedure- found in owner book
Since you are a new owner here is the free owner book with DIYs for all the basic stuff and the normal info on car systems
click your year then model - pdf file- download or read online
https://techinfo.honda.com/rjanisis/...01_OMANUAL.asp
That driver side fan had better come on as soon as the temp climbs to the middle!
Normal temp is a few ticks below middle
Do NOT run the ac while you have this problem- extra load will cause engine damage= blown head gasket
How many miles- was the water pump replaced at 105k miles?
How does the radiator look inside- and the coolant- good color or weak color
Did you use a honda thermostat from dealer?--
but check the air burping
If you buy a new sensor --hopefully its the same size socket/wrench--but sometimes not
06-13-2009, 05:03 PM
#4
10th Gear
Thread Starter
Alright, well I went and bought the sensor (and the freakin huge socket that it takes) but before putting it in and making it non-returnable, I decided to test the fan.
I even used the connection and plugged it right into the AC fan, which works. The driver's side fan, when plugged into the passenger side harness still does not come on with AC, like the original fan does. So now I'm thinking I'm out a fan motor, so I'm off to buy one of those (and return this sensor!).
And for anybody who is curious, the sensor that turns the fan on is on the thermostat housing and requires a 24mm deep socket as far as I can tell.
I did bleed the system, but thanks for that web page/manual. Looks like it will be quite useful. I ran the car with the heat on full blast as soon as I saw the gauge rising, I am only turning the AC on right now to make sure the fans are/are not working.
Car is at 128k miles, but I've only had it for the past 4k. Acura dealership I bought it from assured me it had all of its maintenance and was up to date. May look into that. The only thing I know for certain is a new transmission, but I think that was d/t a recall?
I even used the connection and plugged it right into the AC fan, which works. The driver's side fan, when plugged into the passenger side harness still does not come on with AC, like the original fan does. So now I'm thinking I'm out a fan motor, so I'm off to buy one of those (and return this sensor!).
And for anybody who is curious, the sensor that turns the fan on is on the thermostat housing and requires a 24mm deep socket as far as I can tell.
I did bleed the system, but thanks for that web page/manual. Looks like it will be quite useful. I ran the car with the heat on full blast as soon as I saw the gauge rising, I am only turning the AC on right now to make sure the fans are/are not working.
Car is at 128k miles, but I've only had it for the past 4k. Acura dealership I bought it from assured me it had all of its maintenance and was up to date. May look into that. The only thing I know for certain is a new transmission, but I think that was d/t a recall?
Last edited by ndjs; 06-13-2009 at 05:06 PM.
06-13-2009, 05:14 PM
#5
10th Gear
Thread Starter
This should be an edit: as far as bleeding it, I kinda ballparked the times. From the instructions here: https://techinfo.honda.com/rjanisis/...999O00201A.pdf, you have to have the radiator fans come on, and since mine aren't working, I guessed.
06-13-2009, 08:14 PM
#6
10th Gear
Thread Starter
And now it gets weird...
Fans been replaced. It definitely was not working and definitely does now. It comes on when the AC is on and when the car is hot, but only when the key is not in the ignition. Key in ignition = fans off. No matter the temp. The car will burn itself up if there's a key there. I turn it off and pull the key out and the fan immediately turns on.
Anybody have any idea? I'm headed back to the store to try the sensor again. If this doesn't work, I am completely out of ideas.
Fans been replaced. It definitely was not working and definitely does now. It comes on when the AC is on and when the car is hot, but only when the key is not in the ignition. Key in ignition = fans off. No matter the temp. The car will burn itself up if there's a key there. I turn it off and pull the key out and the fan immediately turns on.
Anybody have any idea? I'm headed back to the store to try the sensor again. If this doesn't work, I am completely out of ideas.
06-13-2009, 08:51 PM
#7
10th Gear
Thread Starter
Sensor is now replaced. Same problem. I am completely spent. $200+ and almost a whole day spent working on this and I am at a total loss. Anybody with any idea, please help. And I also replaced the radiator cap.
Last edited by ndjs; 06-13-2009 at 08:55 PM.
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06-13-2009, 09:53 PM
#8
could be the ignition switch
those had a recall to replace, and then they failed again 2-3-4 times at owners expense- about 50 bucks and easy DIY
find out exactly about the trans- 1-800-382-2238x5 register as new owner and ask for history
odd for a 99 to get a warranty trans--4 speed or 5?
those had a recall to replace, and then they failed again 2-3-4 times at owners expense- about 50 bucks and easy DIY
find out exactly about the trans- 1-800-382-2238x5 register as new owner and ask for history
odd for a 99 to get a warranty trans--4 speed or 5?
06-13-2009, 09:53 PM
#9
the fan temp sensor is on the lower radiator corner on later cars
06-14-2009, 12:31 PM
#11
10th Gear
Thread Starter
My overheating problem just started a couple of days ago and has happened every time I started the car since.
Last edited by ndjs; 06-14-2009 at 12:35 PM.
06-14-2009, 12:43 PM
#12
10th Gear
Thread Starter
Alright, let me try to condense all this into one post so anybody new to the thread doesn't have to read all the above.
The car overheats, but not on the interstate.
1. Replaced the thermostat. No change.
2. Checked the driver's side fan, motor is dead. Replace the motor. Fan now functions, but only when the AC fan is running. If the car is hot when I remove the key from the ignition, the fans will come on and eventually go off, but they will NOT come on if I have the key in the ignition.
3. Replaced the coolant temp sensor (on the thermostat housing). Now the driver's side fan only comes on with the AC. Does not come on when the car is hot anymore, key in or out.
4. Replaced the radiator cap, even though nothing appears wrong with the one I had.
5. Bled the coolant system (again).
So, anybody with any ideas, I'm glad to listen. I'm totally out of ideas at this point.
As far as it possibly being an ignition switch, I don't know how that would affect the coolant system? Especially now that the fans aren't coming on without the AC at all, regardless of the key.
The car overheats, but not on the interstate.
1. Replaced the thermostat. No change.
2. Checked the driver's side fan, motor is dead. Replace the motor. Fan now functions, but only when the AC fan is running. If the car is hot when I remove the key from the ignition, the fans will come on and eventually go off, but they will NOT come on if I have the key in the ignition.
3. Replaced the coolant temp sensor (on the thermostat housing). Now the driver's side fan only comes on with the AC. Does not come on when the car is hot anymore, key in or out.
4. Replaced the radiator cap, even though nothing appears wrong with the one I had.
5. Bled the coolant system (again).
So, anybody with any ideas, I'm glad to listen. I'm totally out of ideas at this point.
As far as it possibly being an ignition switch, I don't know how that would affect the coolant system? Especially now that the fans aren't coming on without the AC at all, regardless of the key.
06-14-2009, 05:56 PM
#14
UB6IB9
06-14-2009, 09:32 PM
#15
ndjs
ignition switch powers many things- power must run thru it and the switch goes bad inside- common failure on 99
Most people experience total engine shutdown while turning a corner when its ignition, the car just shuts off!
You said when the key is in or out affects what happens with the fans??- which leads me to want to inspect the ignition switch
You checked or replaced everything else!!
ignition switch powers many things- power must run thru it and the switch goes bad inside- common failure on 99
Most people experience total engine shutdown while turning a corner when its ignition, the car just shuts off!
You said when the key is in or out affects what happens with the fans??- which leads me to want to inspect the ignition switch
You checked or replaced everything else!!
06-15-2009, 08:32 AM
#17
Drifting
06-15-2009, 11:20 AM
#18
phee- the fans come ON when he removes the key!!--how is that NOT ignition switch related?
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