Help, overheating problem in 2010 Nissan Pathfinder

[ronin026]

I've recently started experiencing issues with my 2010 Nissan Pathfinder V6 overheating. It overheated yesterday while I was leaving the car running in idle with the A/C on. The temp would climb up to the point of overheating, and my wife turned the vehicle off. When I started it back up to see what the symptoms were no more than 2 minutes later it was cool(1/2 up the gauge range), but rose again to overheating. However when I pressed the accelerator the temp would quickly drop down to about 1/2 point(back to normal). It seems to me the only way that the temp could drop so quickly would be if the thermostat was sticking, became unstuck when pressing the accelerator, and a bunch of cool liquid came into the block, quickly cooling the engine back to normal temp. I can't say for sure though and am looking for some help.

The problem persisted, each time quickly resolving itself when I pressed the accelerator. It would take 2-3 second after I pressed the peddle for the temp to drop back into a normal range.

Any help is greatly appreciated.

[mdmellott]

Assuming the belt on the water pump is not slipping, it sounds like you nailed. The thermostat may not be stuck closed but instead not opening completely when it should. At about 180F it should begin to open and should be fully open at about 200K. At that point, it should not close again until it drops to about 170F. If it cannot fully open, revving the engine will push more cooled fluid through the block, like you mentioned.

[AZhitman]

...or a LOT of air in the system.

I'd replace the thermostat, but I'd also pull the radiator, clean the fins, clean the condenser (back to front, to clear the fins), flush the block and radiator, and also flush the reservoir.

[Thommykent]

...or a LOT of air in the system.

I'd replace the thermostat, but I'd also pull the radiator, clean the fins, clean the condenser (back to front, to clear the fins), flush the block and radiator, and also flush the reservoir.

Replace the thermostat, if that fixes it you're good to go. No need doing all this other stuff.

[AZhitman]

There absolutely IS a need to "do all this other stuff."

A thermostat replacement does no good at all if air can't get through the condenser and radiator fins.

It's been on the road for 11 years and there's no mention of cooling system maintenance.

[Thommykent]

If a thermostat fixes the issue, then air is getting through the condenser and radiator fins and there is no real reason to go through the trouble of pulling the radiator since nothing will change. Most people have more important things to do than waste a whole day for no significant gain.

[AZhitman]

False.

It absolutely WILL change something. Maintaining a vehicle isn't "wasting a day," it's making sure it functions as-designed for years to come.

You can have a brand-new thermostat and fresh coolant. Go put a piece of cardboard between the condenser and the radiator and drive across town... and tell me how long it takes for the tow truck to arrive.

Here's what a radiator looks like after 12 years (almost the same age as that Pathy radiator).

You can choose to blow off routine maintenance, but we don't give lazy advice around here.

[ronin026]

I have maintained the Pathfinder. I didn’t include maintenance information since the problem seemed relatively isolated. A full radiator flush was performed within the last 6 months, including bleeding the system effectively until I got full heat/ac function on rear climate controlled air ducts.

Lastly, I’d rather spend 20$(thermostat cost) and an hour and check to see if problems resolved than 20$ and 8 hours and see if problem is resolved.

[ronin026]

If my radiator does look like above picture, I’ll fix that too. I’m not trying to be lazy but rather fix the problem with least possible intrusion. I’m not a terrible mechanic, but the deeper the repair gets the higher likely hood I fumble something and screw up.

[Thommykent]

False.

It absolutely WILL change something. Maintaining a vehicle isn't "wasting a day," it's making sure it functions as-designed for years to come.

You can have a brand-new thermostat and fresh coolant. Go put a piece of cardboard between the condenser and the radiator and drive across town... and tell me how long it takes for the tow truck to arrive.

Here's what a radiator looks like after 12 years (almost the same age as that Pathy radiator).
20200809_120415.jpg
You can choose to blow off routine maintenance, but we don't give lazy advice around here.

It`s money and time wise advice. You just don`t get it. If a vehicle`s engine is cooling as it should, then has an overheating issue and the issue is the thermostat and then it cools as it should after thermostat replacement, then cooling air is passing through the condenser and over the radiator fins satisfactorily. Your example of with cardboard shows how you don`t understand why there is no reason to do anything more than thermostat replacement. With your thinking why not go ahead and replace the water pump for no reason also.

[Thommykent]

If my radiator does look like above picture, I’ll fix that too. I’m not trying to be lazy but rather fix the problem with least possible intrusion. I’m not a terrible mechanic, but the deeper the repair gets the higher likely hood I fumble something and screw up.

Exactly, like everyones father except apparently AZ`s told there son`s. "Don`t fix something if it`s not broke"

[mdmellott]

"like everyones father except apparently AZ`s told there son`s"

This is not alright dude! NICOclub is not a forum like Facebook or Twitter to make disparaging, personally offensive, snarky remarks about anyone.

[Thommykent]

"like everyones father except apparently AZ`s told there son`s"

This is not alright dude! NICOclub is not a forum like Facebook or Twitter to make disparaging, personally offensive, snarky remarks about anyone.

You can choose to blow off routine maintenance, but we don't give lazy advice around here.

what would you call this ! A friendly reminder?

[mdmellott]

what would you call this ! A friendly reminder?

Yes, at best. At worst, constructive criticism. Given the information available at that moment, your advice was lazy. His recommendation was thoughtful and I wish I had thought to include that in my initial reply so that it was as thorough as he made it with that recommendation. Your comment was a personal attack. It had nothing to do with the topic. It was only a hateful comment because he did not support your opinion. Don't bother to reply. I have turned off my email notifications to this particular topic. Have a nice day.

[MinisterofDOOM]

While I don't disagree that in many cases, just replacing the thermostat is good enough, I also know that I personally would rather feel confident than get caught stranded. I have a Lincoln LS8 that put me through three successive summers of repeated overheats. Each time I thought I had found the problem. Each time a new one arose just as I started to trust the car again. Each time left me stranded.

When I pulled the rad in my LS8, it was so plugged up it was probably only 40% effective at best. It was shocking. And it was still "working fine" most of the time. But was it? I mean I pulled it for a reason.
From experience, I would say that overheating issues usually aren't just one-off things. Sure, maybe a stuck-closed thermostat will cause an overheat, and yeah they fail "for no reason" often. But there's still a good chance there's more going on there, and I can tell you there's nothing less fun that getting left stranded by an overheat issue that you thought you fixed...multiple times.

Flush it. Pull the rad. Replace any suspect hoses (especially any with FRP sections, which LOVE to develop microfractures and let air into the system slowly without any signs of leaking), flush the coolant (you'll be shocked at the goop that comes out--none of it conducive to effective cooling). Remember coolant is alcohol, and alcohol is hygroscopic, and moisture is corrosive. For the same reason it's good to flush brake fluid, it's good to flush coolant periodically. The longer coolant stays in the system, the more moisture-saturated it becomes, especially if you have leaks that are letting air into the system.

I know it's a pain. But it's so much better than getting stranded with more overheating.

Just some advice from a guy who has had more overheating issues than he ever hopes to encounter again for the rest of his life.

[AZhitman]

Exactly, like everyones father except apparently AZ`s told there son`s. "Don`t fix something if it`s not broke"

Son, when you've built as many cars as I have, you can lip off. I guarantee you haven't.

Until then, take a seat.

p.s. It's "their sons," not "there son's." Details ALWAYS matter, unless you're lazy.

[Thommykent]

Your points are all valid. I just believe in this case more than necessary.

Ok Grandpa, but I don`t want to take that seat away from buckling old knees.

p.s. the use of a hyphen in moisture-saturated needs to be followed by a noun. Details can bite both ways

[AZhitman]

Understood, and quite possibly overkill. I prefer to be thorough, especially when dealing with cooling (it's hot here).

My knees are fine, strong, and far from buckling, but thanks for your concern.

My post didn't say anything about "moisture-saturated," so you'll have to take that up with the Minister. However, in his post, the word "it" suffices as the noun, since it takes the place of the word 'coolant.'

I'm sure you're good at other things.

Back on topic: Ronin, please keep us posted. I suspect, as TK said, replacing the t-stat and ensuring the system is fully bled should suffice. Pulling the radiator isn't very technical (replacing the thermostat is actually a bigger job), so I think you'll be fine - and if not, we're here to help walk you through it!

[Thommykent]

My post didn't say anything about "moisture-saturated," so you'll have to take that up with the Minister. However, in his post, the word "it" suffices as the noun, since it takes the place of the word 'coolant.'

False, but let`s not continue with that. Like you said pulling the radiator isn`t technical, but cleaning up coolant and ATF isn`t a really fun way to spend a day. Something plastic will always break somewhere also, thus making an easy project a lesson in frustration. That`s why I am a proponent of leave well enough alone.

[Thommykent]

I'm sure you're good at other things.

I`m pretty good at flying 737`s in places such as Japan, Russia and USA.

[Ilya]

I'm sure you're good at other things.

I`m pretty good at flying 737`s in places such as Japan, Russia and USA.

Surprised I haven't seen "737 piloted by Thommy Kent ends up in the drink; investigation concludes he forgot to remove inlet covers" in the news yet. How many times have you half-assed the pre-flight check list and gave it the ol college try and deemed it 'good enough' and the rest of it 'unnecessary'?

(also, who spells Tommy with an H? Seems like 'unnecessary work' to me...)

[Thommykent]

I`m pretty good at flying 737`s in places such as Japan, Russia and USA.

Surprised I haven't seen "737 piloted by Thommy Kent ends up in the drink; investigation concludes he forgot to remove inlet covers" in the news yet. How many times have you half-assed the pre-flight check list and gave it the ol college try and deemed it 'good enough' and the rest of it 'unnecessary'?

(also, who spells Tommy with an H? Seems like 'unnecessary work' to me...)

A moderator who adds BS to the fray should not be moderating.

[Ilya]

Surprised I haven't seen "737 piloted by Thommy Kent ends up in the drink; investigation concludes he forgot to remove inlet covers" in the news yet. How many times have you half-assed the pre-flight check list and gave it the ol college try and deemed it 'good enough' and the rest of it 'unnecessary'?

(also, who spells Tommy with an H? Seems like 'unnecessary work' to me...)

A moderator who adds BS to the fray should not be moderating.

There wouldn't be a fray if it it wasn't for you. That's number #1. #2, everyone on the staff here (especially AZ) has put in hundreds or thousands of hours of their own personal time (and in his case money) over the years to ensure this place is the resource that it is for people like the OP. Instead of acknowledging VERY sage advice from the leader of the place (which would offer OP the best bang-for-buck and longevity of said vehicles cooling system), you got lippy and then started bragging about flying 737's as if you flew one of them to Mars or something (read the room: no one cares). At this point, you're just here to try to prove you're right. YOU are not adding anything to the conversation. I would trust AZ's advice like none other.

Cutting corners and doing just the bare necessity is 'fine' but foolish as you may run into an issue with the components AZ mentioned a few short miles later and have to do the same work again. Why not just do it once and forget about it and know the cooling system is operating at PEAK efficiency? One day spent rehabbing the entire cooling system is better then parts of 2-3 days.

Have a great day. Don't forget those inlet covers... . Now, back to cooling talk.

[Thommykent]

When talked to in a condescending way like this "I'm sure you're good at other things" any one would defend themselves. I am an airline pilot and proud of it. When challenged about my worth to society of course I will say it. Believe me everyone who flies cares about who is keeping them and 180 pople alive, which could include you and your family. The best bang-for-buck is still just replace the thermostat and if it fixes his issue it`s good.

p.s. you should look up the word moderator, comments like this are not moderating "Don't forget those inlet covers"

[AZhitman]

A moderator who adds BS to the fray should not be moderating.

I'll decide that, not you.

Here, let me spare you from the big meanies.

[ronin026]

Ronin026

So I replaced the thermostat, and let the car idle for like 30 minutes in the hot sun with AC full blast and everything stayed cool. Seemed I was good, took the car on a drive and it’s over heating again. This time different symptoms, and I’m wondering if I have air in my system. So was idling great, drove it and it over heated while doing 60 and not climbing any steep elevation mostly flat ground, granted AC was on. It didn’t do this before though as long as I was on the accelerator before it didn’t over heat. So I noticed it over heating and pull over. Check fluid, appears plenty of fluid in reservoir. Let it sit for 15 minutes and start it and let it idle. It overheats again quickly, in like 5 mins.

I watched a video on how to bleed system and tried that but I got literally no air bubbles out was just stream of fluid. I’m in my car on the side of the road letting it cool again or I’d link it.

Anyways what’s the best way to bleed this system? 2010 pathfinder V6 4L LE 4wd.

Also if after bleeding it I’m still having issues what next?

[PalmerWMD]

self deleted since it added nothing useful to the thread.

[AZhitman]

Again, I don't think it's a lack of coolant. I'm still leaning towards airflow through the condenser and radiator.

The fact that it didn't over heat sitting still, but DID overheat at speed, also points towards something uncommon, but a possibility - A bad fan clutch. The only other thing I can think of is the A/T is overloading the cooling system with heat (have you checked your ATF level, and is the fluid clear/pink?)

[ronin026]

I did check ATF fluid yesterday while vehicle was warm(hadn’t been driving just idling for approx 30 minutes, but it was 86 out and parked in the sun) and it was full at the full line, nice pink, free of particles and didn’t smell burnt.

As far as AC condenser, it was just replaced about 3 months ago. Radiator appears OK, it’s original radiator so ten years old and 165k miles but it doesn’t look terrible as far as bent/damaged tines and it isn’t overly full of debris. Going to try and idle it again today and see what I get.

[AZhitman]

That's helpful.

I'm wondering if possibly a prior overheat has compromised either the block or the heater core to the extent it's not maintaining pressure.

My next steps would be pressure test of the cooling system and a compression test on the engine, as well as replacing the rad cap.