I'm not leaking coolant and I'm blow hot air all of the time. It's a quick rise in temp on the temp gauge itself, but when I crank up the heat it levels out just fine. I haven't replaced the coolant since I've had the car (almost been a year) and I haven't done too much other than change the oil. I noticed that the one belt (the smaller of the two) looks somewhat worn and it needs to get replaced. Also, both hoses seem to be warm/hot to the touch.

Both fans work as well.

If I don't turn on the heat, it goes up the the beginning of the H mark and hovers there.

Any ideas what it could possibly be? I'm looking at picking up both belts and a thermostat to replace the current ones this weekend.

2006 G35 Coupe with about 58,000 miles.

I'm either thinking it's a stuck thermostat or the coolant needs to be replaced. When I called around I got a consensus of it being a "clog" in the rad that's common for the 350z's and G's I guess...

Thank you in advance for your help.

 

Is the coolant above the minimum line ?

 

I've never heard of a "clogged" radiator being mentioned either here or over on my350z so I wouldn't call it a common issue. If you have no idea when the coolant was last changed make sure you change it when you replace the belts. I also don't think your thermostat is an issue with only 58K miles, more than likely you've got air in the system and it needs to be burped.

So after you change the fluid, burp the system, burp it again, then burp it one more time. Our cars ARE notorious for being extremely difficult to get air out of the cooling system when air has been introduced into it.

 

Check coolant fluid chemistry and make sure it is still good condition to serve its purpose. If coolant looks good and test out just fine than bleed till you turn blue and that should take care of your issue. If not start with fresh coolant / bleed and see how that goes for you. It could be a thermostat but start with the basics and dig deeper.

 

Thank you guys for the quick responses.

To answer your questions:

1) Yes, the coolant is above the minimum line and expands to about 1 inch below the max line.

2) I don't know the coolant chemistry, how would I go about doing that?

Should I also purchase a new rad cap? I've also heard they've been notorious for causing problems with our cars. Which coolant are we supposed to use?

Bleeding the air out of the system seems like a job and a half haha. I'll be using these two videos to reference when I'm doing this.


Are these good indicators of how to do the job?

Thanks again.

 

I have to agree with the mechanics, probably radiator fins clogged with leaves, bugs, etc. I've never had a vehicle be fine then all of the sudden have air in the system. If it were me I'd probably change the coolant and thermostat (cheap insurance even if its fine) and clean the fins real well with a hose, and for sure the belts because if the big one fails you'll be stranded on the side of the road.

 

The mechanic was talking about inside of the radiator, not debris on the outside. It's clear from debris. I think I will just replace the coolant, thermostat, and the belts.

What else could it possibly be?

 

Just to add to the story, everything was fine this morning until about 15-20 minutes into the drive, then the temp gauge SLOWLY started to creep up without the heat turned on. After I turned it on it crept back down to the normal temperature.

No one around here has the Lisle spill free funnel that everyone talks highly about, and I'm cautious about trying to bleed the system without it.

What's the procedure when bleeding the coolant? I know where the bleeder screw is, but do I take it all the way out? Does it have the notches in it?

I just need to figure out where to go from here.

Thank you.

 

you can bleed without it - just make sure to use the bleeder valve in the rear passenger side of the engine bay. Let the engine warm up. when the needle starts to move shut it down. Wait 2 min. begin opening the bleeder valve slowly so you can hear the air hiss out. When air stops coming out and fluid comes out close it. let vehicle sit for 5 min and repeat. You will need to turn engine on periodically as the coolant cools off too much. The hotter it is the more air will rise to that bleeder valve.


My guess is that you have a thermostat that is partially stuck closed - it is still cycling the coolant but its not fully open so its not going as fast as it should. A simple replacing of this SHOULD fix the problem. I HIGHLY doubt that the radiator is clogged. While you change the T-stat just replace the fluid at the same time.

 

Thank you all for your help!

So, here is a list of the things that I did to the car this weekend:

-Changed the belts
-Drained the coolant
-Took off the thermostat
-Replaced the thermostat and gasket
-Replaced the rad cap
-Replaced the coolant (50/50)
-Turned on the vehicle multiple times and bled the coolant through the release valve

After that, I took it out for run tonight and all seems to be doing well. I found that turning on the heat and revving to about 3000 rpm helped the thermostat to open.

I hope that anyone else who has this problem can use this advice and get it fixed!

I paid roughly around $120 in parts and a shop would have wanted about $400 to get this done!

 

Glad to hear that the g community pointed you in the right direction. They have so many times for me personally!