Hey guys...long time lurker 2nd or 3rd time posting. was wondering if anyone might be able to help me identify this issue.

my baby my 2005 Z is running hot. it starts off fine , meaning 1/3 of gauge then slowly or in one or two jumps, rises to about 3/4 then all of sudden reduces back down to 1/2 or little more than a 1/3. i recently had all three cam sensors replaced and have had a themostat replaced 3 years ago. reservoir is at max and see no signs of leaks. however is some type of black reside on the top of the manifold? i dunno im a girl caught me some slack. grey part around the nissan isignia on motor.. not sure if that has anything to do with the rising tempeatures, its just curious its there and comes off with a swipe and a rag. alot is concentrated around the bolts.

thank you for any help boys n girls !!

-amber

 

Sounds like a thermostat issue. When did the symptom start and what was ambient temperature when it happened?

The grime on engine cover can be from oil vapor or just dust sediment from the road. Irrelevant to the increased coolant temperature.

 

Sounds like a stuck thermostat to me, or possibly an air bubble. You may want to remove the plastic engine cover and take a look around, there might be a bad pcv valve or hose from the pcv.
My engine cover was doubling as a mouse hotel so I launched it.

 

Mine did the same thing when my thermostat went out. Turning the heater on full blast made it drop to normal.. Replaced with a mishimoto low temp stat and very meticulously refilled and burped the coolant, and she was good as new.

 

Prove it

 

Did you replace the original thermostat with an OEM or aftermarket one? How about the cam sensors? Is the black residue sitting on top of the beauty cover then? Any chance you can take a few photos with the cover on and off? Generally, I'd recommend you do a coolant leak test using UV dye, but it doesn't sound like your coolant level is a problem. Is your coolant milky in color? Also, what's the mileage on the car? Have you ever checked your PCV and the grommet? I'm just thinking about what might be causing the residue.

 

Thank you for all the responses!! but yes zak they were oem and no not on the beuaty cover. no , no milky coolant just the usual green.

POS the ambient temp was 1/3 of the way and no fluctuation.

and btw i can prove i am a female and can already tell ii dosnt get laid much

Thanks guys, yall are bomb!

 

Ambient temperature is air temperature outside the car. If the "1/3 of the way" was meant for the coolant temperature gauge, the engine ran a bit too cold which strengthens my suspicion that the thermostat is functioning improperly.

 

LOL. Use a scan tool to read the engine temperature once it's warmed up. This problem should be easy to diagnose.

 

Your name Maggie or Amber? Or should I call you troll?

 

Make sure the radiator fans are coming on.