Hey gentlemen (and ladies, if applicable),

I've had a few issues with the '05 Touring I bought and I'd like your opinion(s)/solution(s) to my issues. I'll start off explaining what I've been noticing:

When I first bought the Z, it had the cold air at idle when 90 is selected on the dial issue. After browsing some topics here, I tried 'burping' the system, and it alleviated the issue. During this process I also came to the conclusion that the coolant system was low on fluid (took approx. 2 quarts of fluid over the course of trouble shooting). The Z is now holding it's coolant level with no issue - I apparently filled it slightly over the MAX line.

Today a new issue happened. I went to the Nissan dealership to pick up some crush washers for the diff and tranny drain plugs (swapping fluids) and on the way back, the coolant temp shot up. I monitored it during driving and as it reached the top limit of normal operation, I pulled over and shut the car off. I let the car cool for approximately twenty minutes and then started it back up. The car was still above the middle of the operating range but lower than when I shut it off, so I turned on the heat, and the temp dropped back to the middle after a minute or so. Also, during this start - it had a ROUGH start and the car did a little shimmy, once it stopped the temp dropped back to normal. Kicking the A/C on brings the temp back up to high, but the temp of the air being pushed out isn't cold. I checked the fans and they're both spinning, but since I can't watch the fans and rev the engine at the same time, I don't know if a fan is shutting off with the A/C on and the engine being run.

What I'm noticing now, is if I'm at idle with the A/C on and rev the engine - the temp will climb up near high. If I turn the A/C off under the same conditions (running full heat instead), the temp does not climb any where near as high. However, during driving, the temp remains consistent (other than when the issue first manifested) and the A/C blows cold.

Is there a way I can certainly tell if it's the fan(s) or if there is just air in the system? Is it something else I am not thinking about?

If you need any more details, comment and I'll provide what I can - The pictures attached are when I was in the parking lot.

The 112 deg C temp is at idle with the car parked, the other is when I was driving back.

 

This may be an idiotic question, well actually, it is, because I'm not familiar enough with these cars, but are there multiple fans speeds on the radiator fans?

After messing around with it this morning, I re-bled the system and found no air. I have warm air at idle with heat on and relatively cold air at idle with AC. Ambient temps are low 80's. I found that I only start to creep up towards the top of the operating temp with AC on and verified both radiator fans are spinning. As I stepped away from the car to put away a tool, one of the fans, which I believe to be the passenger side, momentary spun faster (heard it wind up faster) and then went back to the nominal speed. Well, that nominal speed doesn't cool my coolant fast enough to keep it in the middle of the operating range if you're sitting and revving the engine to approximately 3500 rpms.

Does anyone know when/if/how long the fans are supposed to kick on to that higher speed or if there was an issue they've heard of with the fans not properly kicking into that upper speed?

 

Not attempting to whine, but as a serious question: Almost 100 views and yet no reply, is this forum just not active?

I'll take silence as a yes.

 

Have you done any recent work to the car or is this just something that randomly started happening?

 

Definitely sounds like the fans are not working properly, A/C not cooling at a stop but working at speed is almost always a fan airflow issue.

Is there anything restricting airflow through your condenser/radiator, like a plastic bag stuck in there or something similar?

 

No. I haven't done any work on the coolant system other than filling it a bit when I bought the car. The previous owner wasn't on top of keeping up with maintenance.

There isn't any impedence to the airflow. I haven't had any issues since driving to the dealership. Other than being able to bring the temp up while stationary (3500 rpm with AC on) in my driveway, there hasn't been any overheating issues.

Is anyone aware if the OEM fans are single speed?

Thanks for the replies.

 

My thoughts:

• The fan is one speed. It wouldn’t make any significant difference if it were multiple speeds.
  
  
• You did a check for air in the cooling system, so we can eliminate this from the list of suspects.
  
  
• You said: “What I'm noticing now, is if I'm at idle with the A/C on and rev the engine - the temp will climb up near high. If I turn the A/C off under the same conditions (running full heat instead), the temp does not climb [sic: any where] near as high. However, during driving, the temp remains consistent (other than when the issue first manifested) and the A/C blows cold.”

I wonder if you do not have a warped head gasket. That would give the symptoms you describe.

--Spike

 

There are 2 speeds - hi and low. You can check if the fans are working on both speeds with a simple procedure:
- open the hood
- spray some water on the windshield (if you don't want your wipers clean it on dry surface)
- turn ignition on
- there is a door switch (not on the door) right next to the door lock (you only can see it when the door is open), within 20 seconds after you turned the ignition in ON position puch that door lock button 10 times.
- turn the ignition off
- within 10 seconds turn it back on.
- get out of the car and look at the fans
You will enter test mode for the wipers, lights, A/C and cooling fans. Wait for the car to do all of the tests, cooling fans are the last one.
The car will do the same tests for 3 times, you can turn the ignition off any time to stop the test.
The system will check fans operating on both speeds.

Now, which procedure did you use to bleed the system?
it seems that something either restricts coolant flow or there is not enough coolant (or too much air) in the system.
Did you use air relief plug to bleed?

 

Sorry for the delay - I was out of the state travelling for work.

I completed this procedure and the fans kick on with only one speed. If there's another, higher speed, they're not spinning to it.

I have bled the system using the relief valve on the hose near the firewall and battery compartment and my coolant level is fine.

I'm assuming the heating issue is due to the fans not spinning to this second, higher speed.

 

Check the fan relays, i'm not sure on this car but usually there is a second relay for higher speed, try running power through it directly and see if the fans engage, if so then test the relay. If the fans won't work with direct power than it's most likely a fault in the fan speed controller if there is one, it's usually on the fan shroud or built into the motors.

 

I think I found it, finally. Today I started to overheat again and when I pulled over to investigate the fans, the passenger side fan was not spinning with the AC engaged.

So, new question is: Does cleaning the motor brushes work or should I just spring for a new assembly?

 

Just for the final update/closure on what was going on with the car:

After running the procedure that koren provided - I noticed that the fans were only spinning at the low speed during the diagnostic test - which made me ask the question if the fans were single speed or not. This should have led me to the cause of the fans on their way out, which was confirmed when the passenger side fan crapped out.

I pulled the shroud out of the car via the directions found on one of the previous posts. Just for informational purposes - I pulled the shroud out from the top and the only hoses I completely disconnected were the air intake hose, upper radiator hose, & the coolant reservoir hose (again, via a DIY from the site).

With the shroud out, and after finding a YouTube video for cleaning the fan motor brushes, I decided I should at least check to see if the brushes were stuck instead of dropping the 300 on a completely new fan shroud or the 90 for the replacement motor. After disassembling the passenger side motor, I found all four brushes stuck. I followed the directions in said YouTube video for cleaning the motor brushes and then did the same for the driver's side fan motor (1 brush was stuck). After cleaning/reassembling/reinstalling, I ran the diagnostic and lo and behold the fans spin... on both speeds.

So, I buttoned everything up, bled the system, and I've been driving now for a couple days and my temps are < 190 deg. F, consistently.

In hindsight, I should have documented everything with pictures and written up my own DIY, since the DIYs and guides were a bit haphazard, but I didn't. However, if anyone runs into this issue and needs some help, feel free to PM me.

Thanks for the help, gents.

 

When you took the fan shroud out did you have to take the radiator out also. One of the DIY's with pictures talks about removing the radiator, but it looked like there may have been enough room withour removing the radiator. I've order the fan shroud with motors in place and was hoping I could replace the old one without removing the radiator

 

I have replaced my fans twice in the last 4 years. It's always hot outside where I live. Is anyone else having this same problem? Something is causing these fans to stop working, short in wiring maybe?

I am talking about the two cooling fans right in front of the radiator. From what I understand the fan on the driver side is for the radiator, and the other fan on the passenger side is for the air conditioner. The first time I replaced the fans, neither one worked. The second time, my thermostat failed and the driver side fan motor only burned up. Replaced the thermostat and both fans.

Now, I am on my 3rd fan assembly and both fans worked for maybe a year. Now the passenger side fan wont turn on at all. I first noticed the problem when my air conditioner blew warm air while idling at a red light. The air blows cold while the car is moving. I ran the active auto test and verified that the driver side fan works in slow and fast speed. But the passenger side doesn't turn on at all. The car will run hot when its parked for a long time, but not so hot that the coolant boils out the reservoir relief (which I experienced the first time) and go into limp mode. The temperature gauge needle will go up about 3/4ths of the way, but noticeably higher than normal.

The driver side fan spins smoothly and freely. The passenger side fan will rotate, but it feels like it gets caught up as if the fan isn't securely balanced and rubs the case. But there is not a whole lot of resistance. The 40 amp fuse for the fan is still good.

I also pulled all 3 relays from the IPDM. I rigged them up to a 12 volt battery and used a multimeter to test them. All the relays clicked when voltage was applied to pins 1 and 2. When I checked with the multimeter, cooling fan relay 2 did not shut across pins 3 and 5. Cooling fan relays 1 and 3 did. So I suspect the relay is bad and ordered another one for $9 off eBay. I am going to replace that and see what happens.

If that doesn't work or if I hear a rubbing sound when the fan kicks on, then I will pull the fans out and see what I can do. I will try applying 12 VDC directly to the fan power connector or maybe try to clean up the motor. Is anyone else having this many problems with these stupid fans? Any recommendations for a fan upgrade or think there may be some other problem?




Cooling fan relay 2

 

Are the replacement fans you're using from Nissan? In my experience, the cheaper aftermarket parts now are a total crapshoot, you might get a great one that lasts another 10 years, you might get one that lasts a year or is bad right out of the box.