2004 G35X sedan, 3.5 engine is overheating and all known solutions have not resolved issue.

• checked radiator for leaks - none
  tested radiator, at operating temp - no leaks
  replaced radiator cap (failed pressure test)
  replaced thermostat (old unit tested fine)
  replaced waterpump (it was leaking)

Outside of submitting to the dealer for an expensive probe, I don't know what else to do.

SYMPTOMS
Sitting in park, at idle w/o heat or air running the car runs perfect w/no odd noises, hums, ticks, etc for approx 10-15 minutes. When it reaches operating temp the fans come on however I do not see any rad-fluid flowing as expected.

After performing all the tests and replacing the pump I placed a funnel in the top of the radiator and fills up after reaching operating temp but does not flow. By this time the temp reaches the danger zone so I shut off the car.

Solutions & Suggestions that lead to a solution would be appreciated.

There are two things to check, which it looks like you did. One is "Are you losing radiator fluid?", if the answer is no then you don't even need to check all the listed above and you can go to the second, which it also looks like you did.

Try your above test with the heater running full blast and see if it makes a difference. It's possible the radiator fluid wasn't added correctly and you've got an air pocket in the system. If so, running the heater might solve your problem.

Running the heater was the last test I tried and it only blows cold. I am not loosing fluid, added water in the process of checking it and saw plenty of bubbles come up after replacing the thermostat.

My mechanic said there could be blockage in the block or the radiator or the sensor could be off however I checked the fluid by placing a funnel in the radiator fill hole and it is very hot. When I shut the car off, the fluid that is in the funnel flows back into the radiator.

I don't think the head gasket is gone because there is no white smoke, the oil is not mixed with water & he changed the oil in the process of changing the water pump and there was no water in it.

I am loss!!

Having the car sent to a mechanic in the am.

When bleeding the system, you need to have the front of the vehicle jack up and there is a bleed valve at the back side of the block near the fire wall over by the battery.

Unscrew the air bleed screw to the right of the battery. (Large phillips) its plastic
Remove the radiator cap and fill.
Fill the reservoir in between Low and Full.
Leave rad. cap and bleed screw off and start car, turn heat on full blast.
Let car warm up, put towels under rad. cap and bleed area to catch overflow.
When coolant is visible at bleed screw, put the screw back on tight.
When thermostat opens up coolant/bubbles will rise out of rad. cap. Cap it off now.
Check the level in your reservoir, make sure its in between Full and Low.
Let it idle for a minute or two then turn off heater. Let it idle for another minute and shut off car. Let car cool then check coolant level at radiator and reservoir. Fill to previous mentioned levels.
Should be good to go. Repeat steps if any air is suspect in system.

You just need to burp the air in the system using the air bleeder valve. It's a common issue when people refill the system and don't know there is an air relief valve there.

Gilley wrote:You just need to burp the air in the system using the air bleeder valve. It's a common issue when people refill the system and don't know there is an air relief valve there.

i am going to try that Gilley..... I already know that the mechanic does not know whats going on. He calls saying my thermostat is bad & when I say it's the brand new, he says then it "has" to be the radiator because the bottom hose is cold and want close to $1000 to address what is clearly a guessing game. I left a message with your suggestion, mad that I did not do what I read before sending it to car-max-u-out of money 1st.

Try here

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

Telcoman

telcoman wrote:Try here

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

Telcoman

thanks telcoman...
I reviewed that once before, will give it a closer read today.

spoke with the sales rep at carmax.. WHAT A LAUGH I GOT. they ONLY want $$$$, sad to say. I got blown off when I asked about bleeding the air out, got ignored when I said, I will let you install the old thermostat, you sold it to me and got ignored when I asked if there were any other tests that could be run. He never spoke about gases in the coolant, never spoke about testing or flushing the radiator, he only wanted to talk about the $700 bill to to buy/throw parts at the problem. I will NEVER go to carmax for a repair again. NEVER!!!

pixelmxr wrote:

telcoman wrote:Try here

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

http://www.nicoclub.com/FSM/G35/Sedan/2004/co.pdf

Telcoman

thanks telcoman...
I reviewed that once before, will give it a closer read today.

spoke with the sales rep at carmax.. WHAT A LAUGH I GOT. they ONLY want $$$$, sad to say. I got blown off when I asked about bleeding the air out, got ignored when I said, I will let you install the old thermostat, you sold it to me and got ignored when I asked if there were any other tests that could be run. He never spoke about gases in the coolant, never spoke about testing or flushing the radiator, he only wanted to talk about the $700 bill to to buy/throw parts at the problem. I will NEVER go to carmax for a repair again. NEVER!!!

pixelmxr

Review page CO 6

OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
PFP:00012
Troubleshooting Chart
ABS0001H
Symptom Check items
Cooling sys-
tem parts
malfunction
Poor heat transfer
Water pump malfunction Worn or loose drive belt
—
Thermostat stuck closed —
Damaged fins
Dust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tube
Excess foreign material
(rust, dirt, sand, etc.)
Reduced air flow
Cooling fan does not oper-
ate
Fan assembly —
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio
———
Poor engine coolant quality — Engine coolant viscosity —
Insufficient engine coolant
Engine coolant leaks
Cooling hose
Loose clamp
Cracked hose
Water pump Poor sealing
Radiator cap
Loose
Poor sealing
Radiator
O-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tank
Exhaust gas leaks into
cooling system
Cylinder head deterioration
Cylinder head gasket dete-
rioration

Could be something as simple as a defective radiator cap or some of the items mentioned above.
If the simple items are not the root cause then you may be better off letting a dealer have a look at it.

One of my first major purchases after I first bought my previous 06 G35 was the paper version of the FSM.
A portion of my automotive library


The $300 cost of those manuals is easily amortized over a period of years either by doing easy repairs yourself or having the ability to speak intelligently to both service advisors and the Infiniti mechanic that will be working on your vehicle.
Although the on line FSM will help there is nothing like having the paper volumes that have loads of information easily missed when looking at the PDF on line. It is also much easier to find what you are looking for as well as using post it stickies on various pages.
Once they realize that you are aware of what the diagnosis entails you are less likely to get ripped off.
I learned a valuable lesson years ago in allowing cheaper independent shops do work on my vehicles.
Some of them either don't know what they are doing or they use cheap aftermarket poor quality parts in an attempt to keep costs down.
I have never let anyone but the dealer touch any of my Infinit's and the wife only trusts her Altima at the Nissan dealer.
A week of factory automotive training can cost $10k when you include the training, salary, meals, hotel, rental car, etc.
I'd rather pay the $130/hr labor rate and have the job done right the first time rather than let some a hole just replace parts in the hope he'll stumble upon the fix..
If needed I get the use of a loaner as well as my vehicle being returned cleaner both inside and out than when I dropped it off.

Good luck

Telcoman