QX4 Overheating

[dollerprod]

Hi about a year ago I stumbled on this site because of a problem I was having my the A/C blower and I found this epic thread and it saved me about $500!

So now i'm back with a different question/ problem. I should also say I am not mechanically inclined, but I can follow directions and willing to learn.. Anyway, the truck has been getting very hot when it is idling on a hot day.

Turning the heat on helps the problem. And moving again also helps to cool it down.

Actually I was taking a four hr drive with my fiance and HER BOSS and husband and we were driving my truck on the interstate. I live in FL and it was about 95 deg that day and very still. I guess the heat from the asphalt was just staying on the road because there was no wind. Point of the story, even driving 75-80 mph didn't help with the A/C on. Had to turn on the heat and that really sucked and was embarrassing. It's hasn't been a huge issue since it's been cooler with winter, but still happens on the warm days.

Anyway, this should be the thermostat? And I should buy a manufacturers part from Infiniti right? and not one just from the parts store? Can I buy it online? Is this what I need to be doing?

Thanks smart people! It's a 2002 Infiniti QX4.

[Towncivilian]

Welcome to NICO!

Inspect the radiator cap according to this TSB first, and replace with a new OEM part if necessary.

[Slumpert]

Problem is likely going to be "restricted" radiator either exterally or internaly. Fan clutch / blade or thermostat.

Fan blade is easiest to check for, are all four there? While looking at fan with engine OFF and cold, spin it and note the resistance.

Drive / Idle till temp gauge goes beyond the "normal" zone then immediately pull over, turn it off and check two hoses to see if they are both very hot or is one way cooler than the other.

Also check the fan resistance at that point.

Couple that with checking the cap and coolant level and go from there

[dollerprod]

Welcome to NICO!

Inspect the radiator cap according to this TSB first, and replace with a new OEM part if necessary.

Hard for me to tell...





What is your opinion?

[dollerprod]

Problem is likely going to be "restricted" radiator either exterally or internaly. Fan clutch / blade or thermostat.

Fan blade is easiest to check for, are all four there? While looking at fan with engine OFF and cold, spin it and note the resistance.

Drive / Idle till temp gauge goes beyond the "normal" zone then immediately pull over, turn it off and check two hoses to see if they are both very hot or is one way cooler than the other.

Also check the fan resistance at that point.

Couple that with checking the cap and coolant level and go from there

About checking fan blade- I'm not sure what you mean by "are all four there?" There are 7 blades on the fan itself...? Anyway, when inspecting it, there does appear to be a crack at the base of one of the blades. Although I doubt this is an issue other than should I have it replaced sooner than later to avoid it breaking apart?
Also when checking the resistance- I can spin the blades freely almost a half of a revolution without much effort. Same after it becomes hot.

Drove it until temp went up and pulled over like you advised. Both the top and bottom hoses were extremely hot to the touch.

Crack on fan


Crack on fan




Coolant is full


Thanks very much to both of you for your help! Let me know what you think...

[dollerprod]

Bump for any advice. Just thought it might be some notorious thing for the QX4 that was reported a lot.

Anyway, my brother-in-law, who is much more mechanically inclined than me said that he believes it is the fan clutch.

Likely?

[Chuck Tribolet]

It does smell like a fan clutch to me.

You absolutely positively want to replace the fan itself. If that blade comes off at speed, it can do a
lot of damage.

I think you checked the wrong two hoses. You want the two big ones, one at top (you got that one), one at
bottom (missed that one).

[dollerprod]

Thanks Chuck buddy. Replaced the fan clutch and the temp seems to be doing much better now. Once or twice the temp gauge has gone up to a point I was becoming concerned but all in all it is doing much better and doesn't scare me at a red light. The fan clutch resistance was far too great, so it definitely needed to be replaced. Thanks everyone!

However, I was not able to locate the actual cooling FAN itself. No auto parts store or junkyard seemed to have one. The local dealership did, but they wanted ~$150 for just the fan!
Any idea where I can find a fan?

Again, thanks!

[Towncivilian]

There are no aftermarket options for the fan blade. Dealer or junkyard is the only option. Give Rob a call at 1-866-742-0297, he can give you the best price. Have your VIN ready.