Overheat/high temp issue
04-14-2014, 04:13 PM
#1
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Thread Starter
Join Date: May 2013
Posts: 294
Overheat/high temp issue
I was driving yesterday at 65 mph in a ~50mph brutal headwind in 30° temps and blowing sleet. After an hour I noticed my temp gauge was nearly pegged. WTF. It's never been over halfway in the year that I've owned it. Even in the middle of summer. I though maybe in an extremely odd chance that my condenser was blocked with sleet/ice blocking air flow.
I cracked a window and turned my heat on high to pull some heat out of the system. After 30 seconds or so the temp gauge dropped and steadied in the normal zone. I shut the heat off and it raised back up a minute later. I repeated this cycle a couple of times to verify.
I got home and checked the coolant system. No ice on condenser. Overflow bottle was fine. No leaks anywhere or smells of exhaust in the bottle from a blown head gasket.
( had that happen to anothe car of mine)
I squeezed the upper hose and it was freaking hot but noticed there was no pressure in it. I slowly opened the rad cap to confirm there was no pressure. So, I know my rad cap is bad. The coolant level is still fine. I checked the coolant ratio when I got the car a year ago and it's fine too.
Is it possible my temp sensor/sender is bad?
I cracked a window and turned my heat on high to pull some heat out of the system. After 30 seconds or so the temp gauge dropped and steadied in the normal zone. I shut the heat off and it raised back up a minute later. I repeated this cycle a couple of times to verify.
I got home and checked the coolant system. No ice on condenser. Overflow bottle was fine. No leaks anywhere or smells of exhaust in the bottle from a blown head gasket.
( had that happen to anothe car of mine)
I squeezed the upper hose and it was freaking hot but noticed there was no pressure in it. I slowly opened the rad cap to confirm there was no pressure. So, I know my rad cap is bad. The coolant level is still fine. I checked the coolant ratio when I got the car a year ago and it's fine too.
Is it possible my temp sensor/sender is bad?
04-14-2014, 05:36 PM
#6
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Thread Starter
Join Date: May 2013
Posts: 294
The lower one wasn't because that's the one coming out of the radiator and it was cold yesterday.
someone on another forum said this
then posted this when I asked why the gauge was fake.
someone on another forum said this
the no-pressure thing is weird. it doesnt take much to cool that engine. I wonder if your impeller failed.
the temp gauge is fake in that car btw.
the temp gauge is fake in that car btw.
below one temp, say, 130 degrees, it points at cold.
EVERYTHING from 130 to (i'm just making up the number) 250 degrees causes the needle to point at exactly the same place in the normal range.
above 250 degrees it points directly at hot.
They slow the movement down so it seems like its really telling you something, but its really a three position idiot light.
EVERYTHING from 130 to (i'm just making up the number) 250 degrees causes the needle to point at exactly the same place in the normal range.
above 250 degrees it points directly at hot.
They slow the movement down so it seems like its really telling you something, but its really a three position idiot light.
Last edited by NmexMAX; 04-15-2014 at 06:45 AM.
04-15-2014, 03:04 AM
#7
The way the temperature gauge works depends on what year your car is.
The 3.0 engine in the 2000 & 2001 had 2 temperature sensors. The main temperature sensor is called the ECTS for Engine Coolant Temperature Sensor and is used by the ECU. The other temperature sensor is solely for the gauge in the dash. As far as the engine running, it doesn't matter if this sensor is good, bad or laying on the garage floor. While the accuracy of this sensor can be questioned, it is a linear sensor and is not a "three position idiot light" as quoted above.
In the 3.5 engine in the 2002 & 2003, there is only one temperature sensor. It is the ECTS, same as the 3.0 engine. The temperature gauge in the dash now gets its signal from the ECU.
As to the original post that started this thread, I have a question. Does the engine temperature run normal now that you are not driving into a storm?
Driving into a headwind made the engine work that much harder, like you were going 95 mph. If the engine isn't overheating any longer, I suspect that you may have had a partial freeze over of the a/c condenser coil that sits in front of the radiator. By the time you looked under the hood to check it out, it had melted.
The radiator cap maintaining pressure is important, but more so in summer than winter. The purpose of pressurizing the cooling system is to increase the boiling point of the coolant. 14 pounds of pressure increases the boiling point to approx 250º F. But if everything in the car is working properly, the water pump is pumping its heart out, the radiator isn't plugged at all, the thermostat opening up and the coolant level is full, you don't need a pressurized cooling system. In fact, if you ever develop a coolant leak and you need to drive the car, loosen the radiator cap so that there will be no pressure to spray the water out.
FWIW, the Maxima cooling system regulates the coolant temperature in the range of 180º to 203º. The thermostat keeps the temperature up at the 180 mark and the cooling fans keep it down below the 203 mark. If you monitor the temperature while you are driving, you will see the coolant temperature climb to the 200 mark and then cool down to the 180 mark over and over again. 203º is where the cooling fans turn on and run until the temperature goes down to 180, where they shut off.
The 3.0 engine in the 2000 & 2001 had 2 temperature sensors. The main temperature sensor is called the ECTS for Engine Coolant Temperature Sensor and is used by the ECU. The other temperature sensor is solely for the gauge in the dash. As far as the engine running, it doesn't matter if this sensor is good, bad or laying on the garage floor. While the accuracy of this sensor can be questioned, it is a linear sensor and is not a "three position idiot light" as quoted above.
In the 3.5 engine in the 2002 & 2003, there is only one temperature sensor. It is the ECTS, same as the 3.0 engine. The temperature gauge in the dash now gets its signal from the ECU.
As to the original post that started this thread, I have a question. Does the engine temperature run normal now that you are not driving into a storm?
Driving into a headwind made the engine work that much harder, like you were going 95 mph. If the engine isn't overheating any longer, I suspect that you may have had a partial freeze over of the a/c condenser coil that sits in front of the radiator. By the time you looked under the hood to check it out, it had melted.
The radiator cap maintaining pressure is important, but more so in summer than winter. The purpose of pressurizing the cooling system is to increase the boiling point of the coolant. 14 pounds of pressure increases the boiling point to approx 250º F. But if everything in the car is working properly, the water pump is pumping its heart out, the radiator isn't plugged at all, the thermostat opening up and the coolant level is full, you don't need a pressurized cooling system. In fact, if you ever develop a coolant leak and you need to drive the car, loosen the radiator cap so that there will be no pressure to spray the water out.
FWIW, the Maxima cooling system regulates the coolant temperature in the range of 180º to 203º. The thermostat keeps the temperature up at the 180 mark and the cooling fans keep it down below the 203 mark. If you monitor the temperature while you are driving, you will see the coolant temperature climb to the 200 mark and then cool down to the 180 mark over and over again. 203º is where the cooling fans turn on and run until the temperature goes down to 180, where they shut off.
04-15-2014, 07:17 AM
#8
Senior Member
Join Date: Nov 2005
Location: Austin
Posts: 1,155
Both hoses should be hot to touch! One is not going to be significantly colder to touch because it is the output hose. If you have intermittent overheating with one hose not being hot I would be betting on a thermostat. Those are maintenance items anyways and should be replaced. Replace using a good quality one. Preferably OEM.
04-15-2014, 11:11 AM
#10
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Thread Starter
Join Date: May 2013
Posts: 294
Just took it for a spin again. I noticed as soon as the engine even starts to heat up, but not quite to operating temp, the fans kick on.....and never shut off. It was 30° here this morning and running down thehighway at 60, the fans shouldn't have to be on. There is more than adequate airflow through the radiator.
When the temp gauge pegged again, I pulled over right away and put my dads IR temp gun on stuff and nothing seems to be abnormally hot. Right where the top hose comes out of the block it read 220°. The top of the radiator was 170-ish. The lower hose was still ice cold. This was after 30+ minutes of driving.
Bad temp sensor/sender?
Just took it for a spin again. I noticed as soon as the engine even starts to heat up, but not quite to operating temp, the fans kick on.....and never shut off. It was 30° here this morning and running down thehighway at 60, the fans shouldn't have to be on. There is more than adequate airflow through the radiator.
When the temp gauge pegged again, I pulled over right away and put my dads IR temp gun on stuff and nothing seems to be abnormally hot. Right where the top hose comes out of the block it read 220°. The top of the radiator was 170-ish. The lower hose was still ice cold. This was after 30+ minutes of driving.
Bad temp sensor/sender?
When the temp gauge pegged again, I pulled over right away and put my dads IR temp gun on stuff and nothing seems to be abnormally hot. Right where the top hose comes out of the block it read 220°. The top of the radiator was 170-ish. The lower hose was still ice cold. This was after 30+ minutes of driving.
Bad temp sensor/sender?
Just took it for a spin again. I noticed as soon as the engine even starts to heat up, but not quite to operating temp, the fans kick on.....and never shut off. It was 30° here this morning and running down thehighway at 60, the fans shouldn't have to be on. There is more than adequate airflow through the radiator.
When the temp gauge pegged again, I pulled over right away and put my dads IR temp gun on stuff and nothing seems to be abnormally hot. Right where the top hose comes out of the block it read 220°. The top of the radiator was 170-ish. The lower hose was still ice cold. This was after 30+ minutes of driving.
Bad temp sensor/sender?
Last edited by NmexMAX; 04-15-2014 at 11:25 AM.
04-15-2014, 06:42 PM
#12
Senior Member
Join Date: Jun 2001
Location: Colorado Springs
Posts: 497
How old is the thermostat? Has it been replaced by an aftermarket one? I ask because I replaced my stock thermostat a while back with an aftermarket (Beck/Arnley) thermostat and the cooling fans on the radiator run a LOT more than they used to. Ie, new thermostat is crap and causing my engine to run hotter than it should. If the thermostat gets stuck though, it can cause the behavior you're talking about.
04-16-2014, 09:46 AM
#14
The thermostat is on the passenger side of the engine, where the lower radiator hose attaches. Make sure you use a Nissan thermostat or you will be posting again with more problems.
replace thermostat on 5.5
replace thermostat on 5.5
04-16-2014, 09:52 AM
#15
Senior Member
Join Date: Dec 2008
Location: NYC
Posts: 1,779
The thermostat is on the passenger side of the engine, where the lower radiator hose attaches. Make sure you use a Nissan thermostat or you will be posting again with more problems.
replace thermostat on 5.5
replace thermostat on 5.5
04-16-2014, 12:19 PM
#17
You need to edit your link: http://forums.maxima.org/5th-generat...-write-up.html
Turned out I had a space as the first character and the internet doesn't like spaces in a URL.
04-26-2014, 11:33 PM
#18
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Thread Starter
Join Date: May 2013
Posts: 294
I put a new thermostat, coolant temp sensor and rad cap on. I got the rad cap because the system wouldn't keep pressure, a CTS because I didn't know if it was the gauge or thermostat and a thermostat because I didn't feel there was enough heat in the lower hose so it was either stuck shut or partially there.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
04-26-2014, 11:43 PM
#19
I put a new thermostat, coolant temp sensor and rad cap on. I got the rad cap because the system wouldn't keep pressure, a CTS because I didn't know if it was the gauge or thermostat and a thermostat because I didn't feel there was enough heat in the lower hose so it was either stuck shut or partially there.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
04-27-2014, 12:16 AM
#20
I put a new thermostat, coolant temp sensor and rad cap on. I got the rad cap because the system wouldn't keep pressure, a CTS because I didn't know if it was the gauge or thermostat and a thermostat because I didn't feel there was enough heat in the lower hose so it was either stuck shut or partially there.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
What a pain in the ****ing **** it is to do that thermostat. i hope to never do it again. I've worked on many many cars and done worse projects, but simple item like that shouldn't be difficult. Whoever the engineers are that design **** should have to work on it after it's completed so they know the pain of what should be a simple task.
If I didn't have the exact right length extension, I'd have never got that bottom bolt out. Also, who puts an alternator right under a place where coolant is going to be expelled during the replacing of the thermostat. ****ing stupid.
04-27-2014, 03:35 AM
#23
Don't know if it was the ECTS because even though you tested the fans and they work, the allegedly failing ECTS could simply fail to turn them on.
The fact that your lower radiator hose was cold to the touch when the top one was hot leans towards the thermostat being the culprit.
That being said, I would have replaced both just as you did anyway. very small price to pay to help prevent a warped cylinder head.
The fact that your lower radiator hose was cold to the touch when the top one was hot leans towards the thermostat being the culprit.
That being said, I would have replaced both just as you did anyway. very small price to pay to help prevent a warped cylinder head.
11-03-2014, 08:01 AM
#24
Junior Member
Join Date: Apr 2013
Location: CT
Posts: 21
Same problem here I think....
So finally found this thread....I noticed my cars temp gauge (2000 max se- standard) was climbing into a not to safe zone this past Saturday, kicked my heat all the way up, temp goes roughly to normal operating range. Park the car watch my sons soccer game then go home, no issues hangs in the normal range although still had to heat blasting.
Get home let the car cool down for a few hours checked coolant in radiator and res both at optimal levels.
Yesterday had a 160-190 mile round trip to make for a paintball tournament and made it about 4-5 miles from my house when i noticed the gauge climbing again kicked on the heat all the way and temp dropped down to roughly normal range, because i didn't have time to go back and swap cars i drove out there and back like this (gauge never went past 3/4.) Checked system today still at optimal levels.
Was running late for work this morning, same issues, same temporary solution. I have not had a chance to check inlet and outlet hoses yet, nor fan operation. I did have a few seconds to check the fuses for the fans all are good. I should have enough time in about an hour to check hoses and fans.
This seem like thermostat to you guys?
Get home let the car cool down for a few hours checked coolant in radiator and res both at optimal levels.
Yesterday had a 160-190 mile round trip to make for a paintball tournament and made it about 4-5 miles from my house when i noticed the gauge climbing again kicked on the heat all the way and temp dropped down to roughly normal range, because i didn't have time to go back and swap cars i drove out there and back like this (gauge never went past 3/4.) Checked system today still at optimal levels.
Was running late for work this morning, same issues, same temporary solution. I have not had a chance to check inlet and outlet hoses yet, nor fan operation. I did have a few seconds to check the fuses for the fans all are good. I should have enough time in about an hour to check hoses and fans.
This seem like thermostat to you guys?
12-04-2014, 04:31 PM
#26
Newbie - Just Registered
Join Date: Dec 2014
Posts: 9
Just a little advice on changing the thermostat, try going with a real thin ratchet it works great to remove and replace it. I got in the same boat with my thick kobalt. Couldn't get 2 bolts so I ran to the parts store and grabbed a thin cheap 1/4 in. Drive and it worked perfectly
02-09-2018, 07:53 PM
#28
Newbie - Just Registered
Join Date: Jan 2018
Posts: 2
Amazing intel
The way the temperature gauge works depends on what year your car is.
The 3.0 engine in the 2000 & 2001 had 2 temperature sensors. The main temperature sensor is called the ECTS for Engine Coolant Temperature Sensor and is used by the ECU. The other temperature sensor is solely for the gauge in the dash. As far as the engine running, it doesn't matter if this sensor is good, bad or laying on the garage floor. While the accuracy of this sensor can be questioned, it is a linear sensor and is not a "three position idiot light" as quoted above.
In the 3.5 engine in the 2002 & 2003, there is only one temperature sensor. It is the ECTS, same as the 3.0 engine. The temperature gauge in the dash now gets its signal from the ECU.
As to the original post that started this thread, I have a question. Does the engine temperature run normal now that you are not driving into a storm?
Driving into a headwind made the engine work that much harder, like you were going 95 mph. If the engine isn't overheating any longer, I suspect that you may have had a partial freeze over of the a/c condenser coil that sits in front of the radiator. By the time you looked under the hood to check it out, it had melted.
The radiator cap maintaining pressure is important, but more so in summer than winter. The purpose of pressurizing the cooling system is to increase the boiling point of the coolant. 14 pounds of pressure increases the boiling point to approx 250º F. But if everything in the car is working properly, the water pump is pumping its heart out, the radiator isn't plugged at all, the thermostat opening up and the coolant level is full, you don't need a pressurized cooling system. In fact, if you ever develop a coolant leak and you need to drive the car, loosen the radiator cap so that there will be no pressure to spray the water out.
FWIW, the Maxima cooling system regulates the coolant temperature in the range of 180º to 203º. The thermostat keeps the temperature up at the 180 mark and the cooling fans keep it down below the 203 mark. If you monitor the temperature while you are driving, you will see the coolant temperature climb to the 200 mark and then cool down to the 180 mark over and over again. 203º is where the cooling fans turn on and run until the temperature goes down to 180, where they shut off.
The 3.0 engine in the 2000 & 2001 had 2 temperature sensors. The main temperature sensor is called the ECTS for Engine Coolant Temperature Sensor and is used by the ECU. The other temperature sensor is solely for the gauge in the dash. As far as the engine running, it doesn't matter if this sensor is good, bad or laying on the garage floor. While the accuracy of this sensor can be questioned, it is a linear sensor and is not a "three position idiot light" as quoted above.
In the 3.5 engine in the 2002 & 2003, there is only one temperature sensor. It is the ECTS, same as the 3.0 engine. The temperature gauge in the dash now gets its signal from the ECU.
As to the original post that started this thread, I have a question. Does the engine temperature run normal now that you are not driving into a storm?
Driving into a headwind made the engine work that much harder, like you were going 95 mph. If the engine isn't overheating any longer, I suspect that you may have had a partial freeze over of the a/c condenser coil that sits in front of the radiator. By the time you looked under the hood to check it out, it had melted.
The radiator cap maintaining pressure is important, but more so in summer than winter. The purpose of pressurizing the cooling system is to increase the boiling point of the coolant. 14 pounds of pressure increases the boiling point to approx 250º F. But if everything in the car is working properly, the water pump is pumping its heart out, the radiator isn't plugged at all, the thermostat opening up and the coolant level is full, you don't need a pressurized cooling system. In fact, if you ever develop a coolant leak and you need to drive the car, loosen the radiator cap so that there will be no pressure to spray the water out.
FWIW, the Maxima cooling system regulates the coolant temperature in the range of 180º to 203º. The thermostat keeps the temperature up at the 180 mark and the cooling fans keep it down below the 203 mark. If you monitor the temperature while you are driving, you will see the coolant temperature climb to the 200 mark and then cool down to the 180 mark over and over again. 203º is where the cooling fans turn on and run until the temperature goes down to 180, where they shut off.
Last edited by KokosCamarad; 02-09-2018 at 08:16 PM.
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