Nissan Murano Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Bought a used 2010 nissan murano with 130k miles. Had her for 2 weeks with no issues. Took her for a drive over 45 miles today and she started to overheat. It was all highway. When I noticed it overheating I slowed down considerably and she cooled a little. I tried turning off the AC and it didn't help much. Messed with the ac a couple times and it dropped the temp for a few seconds than the temp kicked back up. When I came to a complete stop the temp went back to normal and stayed normal. I checked the overflow container and the coolant was backed up and full into the container. After I shut the vehicle off the coolant slowly drained from the container. What the heck is going on? Please help.
 

·
Registered
Joined
·
1,613 Posts
Bought a used 2010 nissan murano with 130k miles. Had her for 2 weeks with no issues. Took her for a drive over 45 miles today and she started to overheat. It was all highway. When I noticed it overheating I slowed down considerably and she cooled a little. I tried turning off the AC and it didn't help much. Messed with the ac a couple times and it dropped the temp for a few seconds than the temp kicked back up. When I came to a complete stop the temp went back to normal and stayed normal. I checked the overflow container and the coolant was backed up and full into the container. After I shut the vehicle off the coolant slowly drained from the container. What the heck is going on? Please help.
Since the overheating is happening when the car is at highway speed and you say the temperature stayed within a normal range when the engine is just idling at a stop, my first thought is that there could be a restriction in the cooling system somewhere. A car moving at highway speed shouldn't be overheating as there should be plenty of air flowing through the radiator, even if the cooling fans are off. On a side note, make sure there are no leaves or debris in the grille obstructing air flow through the radiator.

Do you still have contact with the previous owner? If so, ask them if they've used a radiator stop leak or similar product in the cooling system as those can clog the passages in the radiator and reduce flow. Otherwise, you may want to drain the radiator from the lower radiator hose and watch how the fluid comes out--if it's not gushing then that would suggest some restriction in the radiator itself. What's in the coolant that drained out may also give you a clue.

As with any time an overheating event happens, you should cover the other bases as well (e.g. make sure the cooling system doesn't have any leaks, check the operation of the radiator fans, etc.).
 
  • Like
Reactions: Pilgrim

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
No contact with the previous owner. I also have found no leaks. Only from when the fluid backed up into the filling reservoir. It's odd because I have gone 20 to 30 miles before with no issues and have driven it around the city for over an hour. Onlynjad an issue my last road trip at over 30 miles. Thank you
 

·
Administrator
Joined
·
9,099 Posts
At 11 years old around 130K miles, radiator problems are possible.

Since the temp is OK when engine is fully hot and you are driving at low speed, the symptoms tend to rule out thermostat and water pump.

Might be good to replace radiator hoses too, in case one is collapsing.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Thanks. Radiator and hoses would be alot cheaper than the pump. Hope it turns out to be something less expensive.
 

·
Registered
Joined
·
6 Posts
Bought a used 2010 nissan murano with 130k miles. Had her for 2 weeks with no issues. Took her for a drive over 45 miles today and she started to overheat. It was all highway. When I noticed it overheating I slowed down considerably and she cooled a little. I tried turning off the AC and it didn't help much. Messed with the ac a couple times and it dropped the temp for a few seconds than the temp kicked back up. When I came to a complete stop the temp went back to normal and stayed normal. I checked the overflow container and the coolant was backed up and full into the container. After I shut the vehicle off the coolant slowly drained from the container. What the heck is going on? Please help.
Hey, this sounds like a classic example of excessive exhaust back-pressure. Have the exhaust checked, it could be anything from a clogged catalytic converter to a pinched pipe in the system. An exhaust restriction would have little effect at low speeds, but becomes a real problem at highway speeds. Overheating is the first prominent symptom of this.
 

·
Registered
Joined
·
1,613 Posts
Hey, this sounds like a classic example of excessive exhaust back-pressure. Have the exhaust checked, it could be anything from a clogged catalytic converter to a pinched pipe in the system. An exhaust restriction would have little effect at low speeds, but becomes a real problem at highway speeds. Overheating is the first prominent symptom of this.
If the cooling system is operating normally, why would a restricted exhaust cause an overheating condition? If anything, I would expect the opposite. An exhaust restriction causes exhaust gases to pile up and they eventually start to fill the cylinders resulting in the engine not being able to draw in the proper A/F charge for proper combustion. There is actually an entire emissions control system (EGR) built on the premise that allowing small amounts of exhaust to enter the combustion chambers reduces combustion temperatures, which has the side effect of reducing NOx emissions and the possibility of spark knock. In fact, one of the symptoms of a stuck-closed EGR valve can be overheating because combustion temperatures get way too high.

If the OP has a restricted exhaust, he would notice very poor fuel economy and a lack of power when accelerating. If it's bad enough, the engine may start but the car is undriveable.
 

·
Registered
Joined
·
6 Posts
If the cooling system is operating normally, why would a restricted exhaust cause an overheating condition? If anything, I would expect the opposite. An exhaust restriction causes exhaust gases to pile up and they eventually start to fill the cylinders resulting in the engine not being able to draw in the proper A/F charge for proper combustion. There is actually an entire emissions control system (EGR) built on the premise that allowing small amounts of exhaust to enter the combustion chambers reduces combustion temperatures, which has the side effect of reducing NOx emissions and the possibility of spark knock. In fact, one of the symptoms of a stuck-closed EGR valve can be overheating because combustion temperatures get way too high.

If the OP has a restricted exhaust, he would notice very poor fuel economy and a lack of power when accelerating. If it's bad enough, the engine may start but the car is undriveable.
I have personal experience with two cars that overheated only at highway speeds, and in my case, it was because a baffle inside the muffler had broken off and caused a partial restriction. That was a Toyota Highlander. Also, my son's Honda CRV ran fine in in city traffic, but overheated on I81. His problem turned out to be a plugged catalytic converter. It was barely noticeable on city streets. The OPs car may or may not have a similar issue, but here are some links that explain it better than I. It is simple to have a shop do an exhaust pressure check, if it seems that nothing else is wrong. It might be a good idea to do so anyway, since the OP's mileage is so high.

(409) Car Maintenance : Can a Bad Catalytic Converter Make a Car Overheat? - YouTube

Can a Bad Catalytic Converter Make a Car Overheat? (itstillruns.com)

And of course, the other suspect part, the radiator: Overheating only after driving on highway for while and t... (yourmechanic.com)
 

·
Registered
Joined
·
1,613 Posts
I have personal experience with two cars that overheated only at highway speeds, and in my case, it was because a baffle inside the muffler had broken off and caused a partial restriction. That was a Toyota Highlander. Also, my son's Honda CRV ran fine in in city traffic, but overheated on I81. His problem turned out to be a plugged catalytic converter. It was barely noticeable on city streets. The OPs car may or may not have a similar issue, but here are some links that explain it better than I. It is simple to have a shop do an exhaust pressure check, if it seems that nothing else is wrong. It might be a good idea to do so anyway, since the OP's mileage is so high.

(409) Car Maintenance : Can a Bad Catalytic Converter Make a Car Overheat? - YouTube

Can a Bad Catalytic Converter Make a Car Overheat? (itstillruns.com)

And of course, the other suspect part, the radiator: Overheating only after driving on highway for while and t... (yourmechanic.com)
That would definitely be one of the more uncommon causes of an overheating condition. The mechanic in that video even looked a little worn when he was describing the issue as if he spent a lot of time looking for the problem before determining the root cause was a clogged catalytic converter. It's interesting that it happened to both you and your son.

Anyway, I would think there would be some other engine performance issues that are noticeable if an exhaust restriction were bad enough to cause the engine to overheat. Nevertheless, if there is absolutely no problem found with the cooling system then clearly the problem is elsewhere.
 

·
Registered
Joined
·
1 Posts
Bought a used 2010 nissan murano with 130k miles. Had her for 2 weeks with no issues. Took her for a drive over 45 miles today and she started to overheat. It was all highway. When I noticed it overheating I slowed down considerably and she cooled a little. I tried turning off the AC and it didn't help much. Messed with the ac a couple times and it dropped the temp for a few seconds than the temp kicked back up. When I came to a complete stop the temp went back to normal and stayed normal. I checked the overflow container and the coolant was backed up and full into the container. After I shut the vehicle off the coolant slowly drained from the container. What the heck is going on? Please help.
Sry to hear about your problem with your car. I have a 07 Nissan Murano. When mine started to overheat and continued too. I found out it was my alternator. Idk if this helps.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #12 ·
I have personal experience with two cars that overheated only at highway speeds, and in my case, it was because a baffle inside the muffler had broken off and caused a partial restriction. That was a Toyota Highlander. Also, my son's Honda CRV ran fine in in city traffic, but overheated on I81. His problem turned out to be a plugged catalytic converter. It was barely noticeable on city streets. The OPs car may or may not have a similar issue, but here are some links that explain it better than I. It is simple to have a shop do an exhaust pressure check, if it seems that nothing else is wrong. It might be a good idea to do so anyway, since the OP's mileage is so high.

(409) Car Maintenance : Can a Bad Catalytic Converter Make a Car Overheat? - YouTube

Can a Bad Catalytic Converter Make a Car Overheat? (itstillruns.com)

And of course, the other suspect part, the radiator: Overheating only after driving on highway for while and t... (yourmechanic.com)
Thank you. Looks like I could be going down a rabbit hole with this thing. I'm going to try and trade it in for someone more reliable.
 

·
Registered
Joined
·
31 Posts
Bought a used 2010 nissan murano with 130k miles. Had her for 2 weeks with no issues. Took her for a drive over 45 miles today and she started to overheat. It was all highway. When I noticed it overheating I slowed down considerably and she cooled a little. I tried turning off the AC and it didn't help much. Messed with the ac a couple times and it dropped the temp for a few seconds than the temp kicked back up. When I came to a complete stop the temp went back to normal and stayed normal. I checked the overflow container and the coolant was backed up and full into the container. After I shut the vehicle off the coolant slowly drained from the container. What the heck is going on? Please help.
Question, what symptoms were you having when you noticed the overheating ?
was there a physical symptom such as the radiator cap throwing steam ?

If no symptoms were noted, and you had only noticed the gauge on the instrument cluster fluctuating up and down, then it might be a simple fix by checking the temp sensor and or harness connector....otherwise the next step would be the thermostat sticking closed preventing adequate flow through engines cooling system.....pending your mechanical aptitude, replacing the thermostat is a inexpensive fix you can do yourself.

(Edited by Mod.)
 
1 - 13 of 13 Posts
Top