Its an 03 G35 sedan with 80,000 mi. It has fluid. Is there something common with this mileage. I was going to try a thermostat then move to waterpump, but thought I would see if anyone else has issues.

Thanks

 

99.9% is the thermostat, very common on ALL cars

replace that first since its the cheapest and see if that fixes ur overheating

good luck!

 

+1, replace t-stat and coolant flush.


When does it overheat? Highway? or idling in traffic? Or does it not matter??

Fans are coming on right?

 

Has anything changed recently? and when does it overheat? important to help diagnose things...

 

T-stat or air in the system.

If you have not changed anything recently and there is still fluid in your overflow it's the tstat.

Mine is about to go. I had it off the other day when doing some modifications and found it is ready to die. Nismo tstat on order.

 

Start easy and go hard. Bleed the system. 90% cause of all overheating. thermostat is also another cause but dont jump around. Start easy

 

Car Still Overheating

I just replaced thermostat, housing, gasket, and all coolant at 50/50 ratio.
Car still over heats at idle, to make it overheat faster I can turn ac on. The secondary fan is working. First day car overheated in traffic and CEL code was p1217 which is air/fuel not sure if this has anything to do with it.

My only other guess is a water pump. Once again car has almost 80,000 miles and is never abused this is just my go to work car. All stock accept for a K&N filter.

Does anyone have any othter thoughts on what it could be before I pull out water pump. Is there a way to test pump without pulling it out (ex: if I disconnect a hose off the pump while engine is running shouldn't coolant be squirting out, or is this a bad idea)

Thanks for any info going to work on it again on Monday.

 

BTW I forgot too add: service manual seems to be no help as far as symptoms go.

 

Do a compression/leak down test. If you have a blown headgasket, that could also cause overheating. Dont jump to waterpump cuz thats a bitch replace on the vq engines.

 

Also, before anything. blast the heat and see if its hot and touch your bottom radiator hose after warmup to see if its hot. If neither are hot, you got air in the lines.

 

Would a blown head gasket have any other symptoms or a compresion test is only way to go?

 

A. White smoke from exaust
b. Dirty coolant
c. Coolant bubbles with radiator cap off

Check to see if you have any of those. If none of the 3 appear to exist, move on to compression test. If compression is good, move on to figuring out if there is actually air in the lines. If no air, check pump. Idk how to check the pump without taking off the front timing chain cover. I guess you can take off one of the sight covers on the chain case. i would guess the right lower one (black one). Pumps dont usually go bad on these engines and its driven by a chain so if it seizes, you would hear some unusual noises from behind the case.

 

Im keeping my fingers crossed I got to go for a test drive. I think I had air in the lines after the thermo change. I had the car idle for over 20 min with ac on and it didn't over heat yet.

 

Puttin the ac on keeps the fans on forever which doesnt really fix your problem. If you have air in the lines you wil know by.

1. Blasting your climate control on heat and you will recieve normal or cold temp air.
2. Your lower radiator hose will not be hot

If you have air, you dont have heat inside. What are you gonna do in the winter.

 

Haven't heard of head gasket problems on the G for many people.

The lower radiator hose not being hot is typically from a stuck T-stat.

No heat when climate control is at 90* and full speed = air in the system.

Check the oil for choco milk on the oil cap. That is water in the oil = head gasket.

Most commonly its just air in the systems.