Hello! Just purchased a 2007 G35S Sedan.

I noticed last night that the temp gauge was all the way down. (C)
I assume it's the thermometer that is done(?)
Air in the system maybe? (The previous owner said he had just had the coolant changed)

* Happens when i accelerate and highway


Thanks!

 

Hello, and welcome to G35Driver. Just to clarify, when you said that your temp gauge was "all the way down", did you mean that it was not registering any temp reading at all and that the needle was all the way down toward C (cold)? If that is the case, then yes, it is most likely either just air in the system or a faulty or unplugged coolant temp sensor. Either of those scenarios should be easily fixed.

Now, in the interest of being overly cautious (and because you can't always assume that everyone agrees on which way is "down"), if the gauge is all the way toward H (hot), then you should stop driving it immediately until you can get it resolved, as it could do irreparable damage to the engine.

 

Thanks for the welcome!

It hits C when i accelerate or highway. The previous owner had a recent coolant change and complained that the heating (in the car) was was so-so.

I'll burp the car and see if this helps.

Thanks!

 

Wow, if it's not the sensor, then it must be quite a large air pocket to be fluctuating that much.

FYI:

The coolant temp sensor is on the driver's side of the rear mixing manifold, beneath the engine cover, in back of the heads, and near the firewall.

There's two bleeder valves on the driver's side of the car. One is in the heater hose, just adjacent to the shock tower, and the other is on the upper side of the radiator, just behind the air filter housing.

 

Is it possible the thermostat is stuck open? I hate to mention it but I really hope the previous owner didn't pull the tstat out to hide a HG issue.

 

I'll be burping the car tomorrow and hopefully it's air.

What's HG?

 

Head Gasket

 

Head Gasket...i hope not.
I just went out to burp the G but noticed that the coolant in the Reservoir tank is FROZEN!!!!!!!

The coolant is green but frozen solid... I assume i need a full coolant flush(?)

 

yikes, I would.

 

OMG, . . . that is not good at all. Even a head gasket would at least be repairable, but a cracked head or block would become nothing more than an expensive boat anchor. Yes, for God's sake get your coolant issues in order man!

 

Ice will certainly make things cold.

 

TO reiterate G force, before I bought my G I had a 2003 Accord and I had a similar issue. When I sat at a light for a minute or so, the temp gauge would go to the normal/level marker, running properly.

Then, as soon as I started moving and air started flowing over the car the temp gauge would go down (cold) and stay there until I came to an idle.

Pulled the thermostat and it was mechanical, just had a tempered spring that expanded/compressed depending on temperature and 1/2 of the face of the thermostat was broken so coolant was flowing freely.

Hence, stopped, car is hot, thermostat is all the way open. Moving and air flowing, it would cool down and close to restrict coolant but couldn't since half of it was broken off (where the other part went ill never know)

I am hoping that is your issue since it was a simple fix on the Honda and ideally on the G as well.

Just my thoughts.

_Michael

 

Got a new thermostat , bled the coolant.

I noticed that Only the big coolant tube was connected and the other smaller port (for the oil coolant) was closed off. (no tube attached). Should i now be concerned? ...

Also where can i grab a diagram of where exactly the temp sensor is.

Thanks!!

 

Here's a copy of the FSM: http://www.nicoclub.com/FSM/G35/Sedan/2007_G35_Sedan/

Look in the CO (cooling) section and it will cover everything.

(see page CO-24 for a pic showing the coolant temp sensor. It's item #8 in the diagram.)

Given that someone has worked on the car, I'd make sure that sensor is still plugged in properly.

It sounds like someone has done some modding to your car. Perhaps they didn't want the oil cooler to function because you're in such cold territory ( ?? ). Anyway, if that were indeed the reason, it would probably be foolish to have done so, because the oil "cooler" really serves to warm the oil initially, since water temps rise much faster than oil temps. If you're actually looking to bring your oil up to operating temps faster, then you definitely want your oil cooler connected to your engine coolant circuit. Once the engine oil and coolant have come up to full operating temp, only then does the oil cooler actually draw heat out of the oil, as it is thermostatically maintained to a lower temp range than the oil is.

 

Thanks for the feedback! The thermometer was non functionel. Swapped it out and it now all is 100%