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OT: auto mechanic hep

little a

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Jul 4, 2001
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Have a 2007 Nissan Pathfinder.... son’s vehicle. It overheated, I changed thermostat, radiator is fine- and it still overheated after awhile. Read that it might be head gasket or water pump. I don’t think it’s head gasket as it doesn’t have “sludge” underneath oil cap,white smoke or have radiator bubbling while on (cap off). How much am I gonna have to drop and does this sound like a water pump issue?
thanks
 
Yes, and I should additionally say also there is a small annoying click sound which concerned me to shut it off and reconsider having him drive it. After I changed thermostat I drove it around for 15-20 minutes and it didn’t overheat high but it wasn’t normal 25% on gauge..... moved up and down gauge from 25-50% , then when I heard click noise I shut it down
 
Fan clutch.

Thermostat doesn't dictate how hot your car gets. Thermostat's job is to open up when car gets to a certain temp so antifreeze can start flowing.
 
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Burping the system is a good suggestion. Have you determined if the thermostat is functioning correctly now, allowing the coolant to circulate through the entire system? Whenever I see the temp gauge bouncing around, it makes me wonder if there is an air pocket in the cooling system.
 
Fan clutch.

Thermostat doesn't dictate how hot your car gets. Thermostat's job is to open up when car gets to a certain temp so antifreeze can start flowing.
Thermostat is actually designed to open at a certain temp. It actually does dictate the temperature. Your water pump could be shitting on you, with your vehicle, this likely includes timing work. Nissan parts and service are expensive. I wouldn't wait on it with it being cooling system related.
 
Thermostat is actually designed to open at a certain temp. It actually does dictate the temperature. Your water pump could be shitting on you, with your vehicle, this likely includes timing work. Nissan parts and service are expensive. I wouldn't wait on it with it being cooling system related.

Yes and no...thermostat is not designed to cool motor. Yes it opens at a certain temp, but the fan clutch will actually help cool the car, once the Stat opens it's job is done.
 
Yes and no...thermostat is not designed to motor cool. Yes it opens at a certain temp, but the fan clutch will actually help cool the car, once the Stat opens it's job is done.
The thermostats sole function is to open at a predetermined temperature, and close at another predetermined temperature. The coolant and fan are doing the physical cooling. Not interested in a dumb argument. Your first statement was incorrect. Have a nice day.
 
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The thermostats sole function is to open at a predetermined temperature, and close at another predetermined temperature. The coolant and fan are doing the physical cooling. Not interested in a dumb argument. Your first statement was incorrect. Have a nice day.

Take the Stat out completely, your car will run fine and never over heat. Take the fan clutch off, and you're driving a ticking time bomb.
 
Thanks- fan seems to be running fine.....

Cannot check them visibly, you have to roll the dice and just replace it...and you mentioned earlier about hearing a ticking sound, which can be a sign of a bad one. If this car was in my family, and based on everything you have stated here, I'd put a fan clutch in it.
 
Take the Stat out completely, your car will run fine and never over heat. Take the fan clutch off, and you're driving a ticking time bomb.
It may not overheat without a thermostat but the vehicle also is never allowed to come up to proper operating temperature which actually can cause some other issues
 
Crank the AC while driving and give it some gas pedal and see how it behaves. Bad or failing fan clutch can present itself
 
It may not overheat without a thermostat but the vehicle also is never allowed to come up to proper operating temperature which actually can cause some other issues

I agree...the car will run cool and may never heat up.....because the thermostat doesn't cool the motor :)
 
My fist thoughts would be head gasket or intake gasket and/or air pocket in the coolant system. Back in the day, I had a similar issue with my 99 Grand Am, I never did figure out and ended up selling it cheap to a guy who had the time and knowhow to fix it for himself (it also had a body issue). The air pocket in the system was a sure thing, the question was what kept causing it to come back after burping and a gasket was the likely culprit from what I've even told.
 
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My fist thoughts would be head gasket or intake gasket and/or air pocket in the coolant system. Back in the day, I had a similar issue with my 99 Grand Am, I never did figure out and ended up selling it cheap to a guy who had the time and knowhow to fix it for himself (it also had a body issue). The air pocket in the system was a sure thing, the question was what kept causing it to come back after burping and a gasket was the likely culprit from what I've even told.

If it was a Quad 4 I think they came stock with that issue...worst design, ever.
 
Have a 2007 Nissan Pathfinder.... son’s vehicle. It overheated, I changed thermostat, radiator is fine- and it still overheated after awhile. Read that it might be head gasket or water pump. I don’t think it’s head gasket as it doesn’t have “sludge” underneath oil cap,white smoke or have radiator bubbling while on (cap off). How much am I gonna have to drop and does this sound like a water pump issue?
thanks
One thing you didn't mention - since you changed the thermostat did you 100% confirm that it was stuck closed? Also, when you say "it overheated" how hot was it? Did it just get hot on the gauge or did it puke out all the coolant and stop running? If it really got hot and was pinging and blowing coolant out the overflow it probably has a cracked head. If you can visually see coolant flowing in the radiator or in the reservoir tank I doubt you have a water pump issue.
 
One thing you didn't mention - since you changed the thermostat did you 100% confirm that it was stuck closed? Also, when you say "it overheated" how hot was it? Did it just get hot on the gauge or did it puke out all the coolant and stop running? If it really got hot and was pinging and blowing coolant out the overflow it probably has a cracked head. If you can visually see coolant flowing in the radiator or in the reservoir tank I doubt you have a water pump issue.

good points....It did overflow according to my son. I did all the teats for cracked head (white smoke, oil cap “sludge”, radiator overflow within one minute with bubbles) and it was negative. I’m just gonna have to take it into professionals
 
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I agree...the car will run cool and may never heat up.....because the thermostat doesn't cool the motor :)
The statement I was refuting was that the thermostat did not dictate how hot the engine gets when that is precisely what it does I never said the thermostat physically cools the engine. Come on man.
 
I would check to see if the fans are spinning properly. With the car in park and the engine running oh, turn the AC on full-blast. Both fan should be spinning. If not, you can replace the fan assembly. But first, I would have the battery checked and the alternator as failing components can cause similar symptoms.

Nissans are known for blown head gaskets. You can buy kit on Amazon that will allow you to check to see if that's the case. If that's the case you can decide if you want to put any more money into this vehicle. Nissan was a middle of the road manufacturer of automobiles until Renault bought them out. Now they have awful transmissions and blown head gaskets.
 
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It never hurts to change or at least check the little things like a radiator cap. Every once in a while you get lucky and it's not something more involved.
07 is probably too new for it to be the radiator cap.

I'd start by rotating all of the circular and secondary filter rotors. Never can tell when the wheel bearings are going to flip and need secondary cooling from the drive manifold.
 
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I would check to see if the fans are spinning properly. With the car in park and the engine running oh, turn the AC on full-blast. Both fan should be spinning. If not, you can replace the fan assembly. But first, I would have the battery checked and the alternator as failing components can cause similar symptoms.

Nissans are known for blown head gaskets. You can buy kit on Amazon that will allow you to check to see if that's the case. If that's the case you can decide if you want to put any more money into this vehicle. Nissan was a middle of the road manufacturer of automobiles until Renault bought them out. Now they have awful transmissions and blown head gaskets.

yep, you are correct on the Renault..... ugh. Reading up on them it was horribly made when it came to radiators coolant/transmission leaks (strawberry milkshake of death). The good thing is I got my money out of it— made it to 155000 miles. My son was driving it and I don’t think he was paying attention to it going hot- he feels bad about it
 
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I would check to see if the fans are spinning properly. With the car in park and the engine running oh, turn the AC on full-blast. Both fan should be spinning. If not, you can replace the fan assembly. But first, I would have the battery checked and the alternator as failing components can cause similar symptoms.

Nissans are known for blown head gaskets. You can buy kit on Amazon that will allow you to check to see if that's the case. If that's the case you can decide if you want to put any more money into this vehicle. Nissan was a middle of the road manufacturer of automobiles until Renault bought them out. Now they have awful transmissions and blown head gaskets.

battery and alternators? Sorry I’m a novice...
 
Could also try a coolant flush. If it's never been changed it could be full of sludgy coolant
 
Not to be a jackass, but have you checked to see if the radiator is just plugged up with cotton from the cottonwood trees? It happens more often than people would realize.

An 07 isn't going to be sludged up unless somebody added the wrong coolant. The click you are hearing is most likely the AC clutch. I'll almost guarantee you that there isn't an air bubble or a problem with the radiator cap since its an 07. If its actually overheating, its probably an air flow deal so just take it out, get it up to where it says its overheated, and then turn the heater on full blast and see if that takes the temp down. If not, it might just be a bad sensor and the car isn't overheating at all.
 
Not to be a jackass, but have you checked to see if the radiator is just plugged up with cotton from the cottonwood trees? It happens more often than people would realize.

An 07 isn't going to be sludged up unless somebody added the wrong coolant. The click you are hearing is most likely the AC clutch. I'll almost guarantee you that there isn't an air bubble or a problem with the radiator cap since its an 07. If its actually overheating, its probably an air flow deal so just take it out, get it up to where it says its overheated, and then turn the heater on full blast and see if that takes the temp down. If not, it might just be a bad sensor and the car isn't overheating at all.

thanks, I’ll try anything. I live in Texas so cotton wood is an issue but I don’t see anything clogged
 
thanks, I’ll try anything. I live in Texas so cotton wood is an issue but I don’t see anything clogged
You can't really see it. Its kind of a pain in the butt, but if you can take the shroud off of the top access, just take some foaming carpet cleaner and soak the heck out of both sides and let it set for 10 minutes. Then hose it down. You'll be surprised how much stuff comes out. Yeah, its kind of a redneck solution but if you've gone this far, the shoe fits.
 
Have you tried swearing at? Also, did you blame your son yet? Something like "How did you mess this up, why don't you take care of your things...stop...stop...well if I can't fix it you are walking from now on"

yea, I of course blamed him but didn’t go Full Pelini, as y’all know you never go full Pelini
 
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