SFerg

05 350z

Things I have done:

New Radiator installed 2-3 months ago, it has ran fine (Replaced due to small leak in radiator)
Ran great for a couple months

Recently the engine gets pretty toasty. (Needle gets a little over half)
After a long drive (1hour+) Needle goes a little over half then back to under half. This happens a couple times.
Turning AC off doesn't help
Heat works great, consistent and hot, cold is cold and consistent.

I have flushed the coolant system and had nissan vacuum any air out.
I have mishimoto radiators fans, they turn on when supposed to.
I have replaced Thermostat with an new OEM thermostat.
I have replaced the radiator cap with an new OEM radiator cap.
I do not have an undertray.

srv1990

Does it fluctuate on the highway or just idle? Also I know you said your fans are working properly but I'm curious if its getting hot enough for the high fans to kick on? Also what kind of radiator was installed?

eZg

iTrader: (5)

How is the coolant level?

Soooooo often there is air in the Z's system, but you say it has been vacuumed out.

Only other thing I can think of is cheap coolant??

Gl......hope you figure it out before 120 degrees there

SFerg

Fluctuates on the highway, and I have a new OEM radiator installed.

SFerg

0 air, I guarantee it. I am using O'reilys coolant with distilled water. 50/50. Maybe I will try some water wetter to see if that helps.

eZg

iTrader: (5)

Maybe try the nissan blue coolant?

I'm not an electrical engineer or anything but wonder about testing the power to the fans?

I got into this a bit when I installed some larger spal fans. I tried setting up relays and running thicker wiring but had to resort back to stock wiring.......so I sure wouldn't recommend jacking around with wiring. Maybe one of your stock relays is having intermittent issues??

wisniaPl

Burp the system with funel...burp burp
Do you have oem t Stat?

SFerg

OEM Thermostat and OEM gasket, I have the funnel. I burped it earlier, going to try it again.

SFerg

I will replace the stock fan relay and fuse just to make sure, I will also pull out my volt meter and test, but I doubt that is going to be the issue, we will see though.

rawgarage

iTrader: (3)

Run with full heat on and evacuate the air from that bleeder valve behind the engine....

wisniaPl

Do that when burping with funell let us know

SFerg

I bleed and bleed, I am not getting very far with this cooling issue. I can drive for about 30minutes to an hour before it gets a little over half. I just got a new OEM radiator cap for the thing too...

srv1990

I know this probably won't help, but there is an easy way to verify the cooling fan operation and/or relays by initiating the Auto Active Test. Its a quick self diagnostic in which the IPDM E/R tests the following in this order.

1. Rear window defogger (10 sec)
2. Front wipers low (5 sec) high (5 sec)
3. Parking, licenses plate, and tail lamps (10 sec)
4. Low headlamp (10 sec)
5. High headlamp (on-off 5 times)
6. A/C compressor magnetic clutch (on-off 5 times)
7. Cooling fan low (5 sec), high (5 sec)

Auto Active Test Procedure:

1. Close hood and passenger side door, then lift wiper arms away from windshield.
(This can also be done with the hood open, wipers down, and is best to wet the windshield beforehand)
2. Turn ignition switch OFF.
3. Turn ignition switch ON and within 20 sec. press drivers front door switch 10 times.
4. Close driver side door, then turn ignition switch OFF.
5. Turn ignition switch ON within 10 sec.

If completed successfully the horn will quickly chirp once and the oil pressure warning light will start blinking. Auto Active Test then begins. The test will repeat itself 3 times but can cancelled at any point by turning the ignition switch off. Again, I'm sorry none of this probably helped but may save some time and money eliminating the cooling fans and/or relays as part of the problem.