Path is running hott..

[95champagnepath]

So recently after moving down here to az, I've noticed that while driving on the freeways with the A/c running or just having the path sit at idle in the sunlight with the A/c running will cause the pathfinder to heat up rather high. Around 3/4 of the temp gauge and sometimes even higher. Not sure what the actual temp is. You can feel a loss in power while driving at that temp as well.

 

Just a couple days ago, I dropped a new radiator, radiator cap, and thermostat in. Flushed the coolant, and it's got a new water pump as well. Figured that would do the trick, but it's still running pretty hot on the freeways . Once I turn off the A/c or run without the A/c, it'll warm up right to halfway, maybe even a little less.

 

Was wondering if anyone had any ideas on what could be the issue. No leaks, at least that I can find. Could it be a bad sensor?? These past few weeks it's been over 105 and sometimes even above 115. Could it just be too hott? It only happens when I run the A/c as well. Possibly the fan? But that runs at idle so I wouldn't think it would stop spinning when driving on the freeway. Any ideas??

[MY1PATH]

Can you see light thru the radiator if you put a light between it and the the AC?

Did you you use more than 50% coolant? ("coolant" is acutually not very thermal efficeint, it prevents boiling, freezing and corosion but the water does 90% of the cooling)

Did you burp the system of air?

Using purified water instead of hose water may help as well.

 

3/4 is about normal, my truck used to run that in cali. Higher is a little concerning esp if it crosses over into the H.

[Precise1]

Well, 3/4 is too hot unless you have a malfunctioning temp gauge. The new radiator, T-stat and cap is a good idea but it seems like you are right on the hairyedge of the cooling system efficiency if the AC can push it that much farther (remember that the AC condensor is in front of the radiator so it will heat up the air pre-radiator). Could you have any scale or corrosion in your water channels? Perhaps a cooling system chemical flush would help?? The fan clutch would only make a difference at idle/slow speeds.

 

If you have not gone to the Garage section and downloaded the FSM for your year, do so (hint, pinned at the top) and check how to trouble shoot the sensor. Hopefully there is a resistance spec.

 

Also do you have any thermometer, either from a multimeter, meat thermometer or anything thay you could get an actual temperature reading of the coolant??

 

B

[adamzan]

Mine climbs to just over half when it was 102F 2 weeks ago. I had the a/c on and the fan clutch is what makes the truck gutless.

[Slashjt]

Mine is a little bit below half running normal.

In long climbs rises until 3/4 and stays there.

Doing trails, if I give it 6000rpm in 4low for too long it gets a little got, a bit over 3/4.

 

New temp bulb, thermostat, coolant, etc.

[87pathy]

do you have a shrowd on your fan / rad?

[ahardb0dy]

My fan clutch on my 94 was shot and the truck, even in traffic would never go near the halfway point on the temp gauge, even with the ac on and it's in the high 90's here everyday, with the new fan clutch it is still reading the same temp, and I tried replacing the sender for the gauge just to see if the original one was bad, same temp with either sender.

 

I would do as previously suggested and see if there may be air in the system which will make it run hotter, also I just bought some coil cleaner (from Home Depot) for my home AC unit and some of the people that used it and reviewed this cleaner said it worked really well on their condensers in their vehicles,

[tmoore4512]

Had the same issue, went with a taurus e-fan, and my problem was solved...run my AC all the time too...(and it blows colder air!!!)

 

Good luck bro.

[95champagnepath]

Can you see light thru the radiator if you put a light between it and the the AC?

Did you you use more than 50% coolant? ("coolant" is acutually not very thermal efficeint, it prevents boiling, freezing and corosion but the water does 90% of the cooling)

Did you burp the system of air?

Using purified water instead of hose water may help as well.

 

3/4 is about normal, my truck used to run that in cali. Higher is a little concerning esp if it crosses over into the H.

 

I'll check the light technique when it's a little darker. What would that determine? The coolant I put in is 50/50 water and coolant with a boiling temp at 265 degrees. How would I remove any air in the system? Haven't added any water to the system.

 

Well, 3/4 is too hot unless you have a malfunctioning temp gauge. The new radiator, T-stat and cap is a good idea but it seems like you are right on the hairyedge of the cooling system efficiency if the AC can push it that much farther (remember that the AC condensor is in front of the radiator so it will heat up the air pre-radiator). Could you have any scale or corrosion in your water channels? Perhaps a cooling system chemical flush would help?? The fan clutch would only make a difference at idle/slow speeds.

 

If you have not gone to the Garage section and downloaded the FSM for your year, do so (hint, pinned at the top) and check how to trouble shoot the sensor. Hopefully there is a resistance spec.

 

Also do you have any thermometer, either from a multimeter, meat thermometer or anything thay you could get an actual temperature reading of the coolant??

 

B

 

Don't think there is any corrosion. Nothing was visible. What kind of chemical would be used for the chemical flush? I'll check the FSM's and try to get a temp on the coolant.

 

do you have a shrowd on your fan / rad?

 

Yeah still has it. As well as skid plate, which one mechanic said would help cooling, but not too sure how it would effect it... haha

 

My fan clutch on my 94 was shot and the truck, even in traffic would never go near the halfway point on the temp gauge, even with the ac on and it's in the high 90's here everyday, with the new fan clutch it is still reading the same temp, and I tried replacing the sender for the gauge just to see if the original one was bad, same temp with either sender.

 

I would do as previously suggested and see if there may be air in the system which will make it run hotter, also I just bought some coil cleaner (from Home Depot) for my home AC unit and some of the people that used it and reviewed this cleaner said it worked really well on their condensers in their vehicles,

 

 

Odd thing is, the A/c still blows cold at this temp and sometimes is even colder than when it's running at halfway mark.

[nunya]

Fan clutch would be my suggestion... mine runs hot in stop and go with the a/c on, thinkin mine is goeing bad as well. That or when was the last water pump done? I've seen a fiew times that the blades would corrode away and not actually "pump" water well.

[95champagnepath]

Did the water pump along with the timing belt this past December. Is there a way to test the fan to tell whether or not it's going bad?

[ahardb0dy]

when you rev the engine you should be able to hear the fan spinning faster sounds like a jet, that's what mine wasn't doing, when I revved it the fan kept spinning the same, you can also when the engine is OFF check the fan clutch for play by trying to move the fan blade, or try to stop the fan blade from spinning using a piece of cardboard or something, you shouldn't be able to stop it that easily.

 

 

air relief screw looking at the engine, right side of intake manifold towards the rear:

 

 

Edited July 20, 2010 by ahardb0dy

[nunya]

I always go with the "park facing uphill on an incline and run the truck with the rad cap off" way of burping the air out of my cooling system. Helps my driveway ain't level though...

[jj big shoe]

If it still doesn't cool efficiently on the highway I doubt it has anything to do with the fan or clutch. Sounds like coolant flow or a blockage would be the problem to me. Besides, when fan clutches go bad, don't they usually sieze up so they're always on?

Pop the cap off the rad (when the engines cool, of course) and watch for coolant flowing past when the t'stat opens. If your temp gauge is over 1/2 and there isn't any flow yet, I'd really suspect the t'stat. If there's only a slight flow, there's prolly a blockage somewhere or the t'stat isn't fully opening. BTW, that's also how I've always "burped" my cooling system. Once the flow starts it'll move the air bubble around and you'll see the coolant in the rad drop, then just fill it up.

[ahardb0dy]

the fan clutches don't always seize up or stay in the "engaged" position, mine was just spinning along, have you tried flushing the cooling system maybe even a few times?

[edicer2]

mine never goes more than 1/3 of the way....i was going 80 on the highway for almost 3 hours with ac on in 95 degree weather also. intown it never goes above a 1/4

[Precise1]

If it still doesn't cool efficiently on the highway I doubt it has anything to do with the fan or clutch. Sounds like coolant flow or a blockage would be the problem to me. Besides, when fan clutches go bad, don't they usually sieze up so they're always on?

Agreed, but the fan clutches can fail in the lax direction, they dont tighten up enough to cool at idle/slow speeds.

 

What kind of chemical would be used for the chemical flush?

I don't know the brands as I haven't needed any, but it is not uncommon at all. Someone else will advise or simply go to the local auto parts store and ask.

 

B

[nismothunder]

Fan or you could try some of that purple ice or what ever,it will cool the water temp by up to 18f

[Tungsten]

mine never goes more than 1/3 of the way....i was going 80 on the highway for almost 3 hours with ac on in 95 degree weather also. intown it never goes above a 1/4

 

thermostat failed?

[95champagnepath]

when you rev the engine you should be able to hear the fan spinning faster sounds like a jet, that's what mine wasn't doing, when I revved it the fan kept spinning the same, you can also when the engine is OFF check the fan clutch for play by trying to move the fan blade, or try to stop the fan blade from spinning using a piece of cardboard or something, you shouldn't be able to stop it that easily.

 

 

air relief screw looking at the engine, right side of intake manifold towards the rear:

 

 

 

Thanks hard body for the image. Gonna try to burp it and see if it works.

 

If it still doesn't cool efficiently on the highway I doubt it has anything to do with the fan or clutch. Sounds like coolant flow or a blockage would be the problem to me. Besides, when fan clutches go bad, don't they usually sieze up so they're always on?

Pop the cap off the rad (when the engines cool, of course) and watch for coolant flowing past when the t'stat opens. If your temp gauge is over 1/2 and there isn't any flow yet, I'd really suspect the t'stat. If there's only a slight flow, there's prolly a blockage somewhere or the t'stat isn't fully opening. BTW, that's also how I've always "burped" my cooling system. Once the flow starts it'll move the air bubble around and you'll see the coolant in the rad drop, then just fill it up.

 

After putting on the radiator and tstat, I let it run outside in the 108 degree sun with A/C going full blast for about 20 min. Came back and it was right at halfway. After driving on the freeway with the A/c going, it heated up to 3/4. Parked it for about 10 min and it wouldn't cool back down to halfway. So I guess the only way to check the flow that would be to pop the cap off after driving on the freeway... which probably wouldn't be a good idea... haha

 

mine never goes more than 1/3 of the way....i was going 80 on the highway for almost 3 hours with ac on in 95 degree weather also. intown it never goes above a 1/4

 

Yeah, when I was up there in Kato, it never went above 1/3. Even on those warm days. Just started last summer after I moved down here and was driving around on some hott days.

 

Fan or you could try some of that purple ice or what ever,it will cool the water temp by up to 18f

 

I'll give that a try if the burping technique fails.

[95champagnepath]

Probably would be a good idea to let it cool before burping it. Or can I go ahead and try now, just got back from work, pulled in the garage and it was at half temp and holding. No freeway driving though and it's not as hot out. Only about 105.

[nunya]

let it cool off completly before opening the rad cap... not worth getting burnt the f-up when it depressurizes at a high rate of speed out the cap.

[95champagnepath]

In order to open the air relief plug, the radiator cap has to be off?

[nunya]

Ignore me... Forgot you got a little bleeder screw. I was thinking my old fashoned way.

[95champagnepath]

haha so it should be fine to turn that screw when it's warmed up then?