I would have someone who knows heads check them out. It's quite possible
you could get the motor up and running by just having the heads trued and
a valve job done if needed....new gasket and you're back on the road. Like
Texasscout mentioned trade it in while no one's looking....LOL
Gary

 

Strange. Why does it take a week or two to overheat? Are you checking the radiator fluid level regularly?

Clearly you are losing coolant and it takes a week for it to loose enough to overheat the motor. You should really be checking it and NOT waiting until it overheats everytime.

You probably have a coolant leak from a slightly blown headgasket.

The dealer should be peforming a leak down and a compression check vs just guessing. Hell I could guess better than that.

 

I agree with jeff, this is complete horsesh1t. I had a lexus that had the same problem and it was a blown headgasket. I got it fixed for 1200 bucks and was a noob and probably got ripped off a bit.

 

Thanks but we are not going the fi route. I was thinking along the lines of bang-for-the-buck mods (cams, tb, etc.).

 

I checked the levels in between occurrences and everything was normal. The service rep mentioned they had to top-off the coolant the first two times they got the car.

That's kinda what I'm getting at here.

 

These things are already so "tweeked and peaked" that FI is really the ONLY "bang for the buck". You MAY get 35-50 more HP going NA and it will cost you just as much as FI.

 

First you need to find out if the car is actually over heating. The temp guage sensor might be bad, giving u false readings. Nissan uses two temp sensors, one for the ECU and one for the gauge in the car.

If the car is over heating (boiling coolant), then it is loosing coolant probably thru the engine. Did you notice any white smoke? exhaust smells like syrup?

I would put in some stop leak and trade it in asap.

 

A temp sensor wouldn't cause an overheat. A stock thermostat might.

Again a leakdown test/compression test is in order here.

Did you check the fluid level each time it overheated?

 

One of the heads had a crack in it. New heads on the way.

Thanks to all who helped.

On that note, I may have an '03 G sedan for sale.

 

Normal better than average educated technicans would do a hydrocarbon leakage test- measuring if any combustion gases are leaking into coolant.

http://www.troubleshooters.com/toverheat.htm

Sorry about the picture cannot delete it from link?????

http://www.freepatentsonline.com/4102178.html

 

That's what ticked me off about the service dept at the dealer.

The day we dropped the car off at an independent mechanic, he called to tell us that he did a pressure test and saw coolant leaking from the passenger side head.

What did he know that the service dept at the dealership didn't?

 

A pressure test is very different from a test to see if combustion gases are present in coolant.

Either way a cracked/failed head effectively proves serious owner abuse in allowing an overheat.

 

You should stop using the dealer for service as soon as your warranty runs out.

 

The rub with not using dealer on new models is the serious redesigns the V6 got in 2002 and the every year subsequent redesigns to fix problems.

As an independent group of 3 shops [15 techs] who speciliaze in just Infiniti and Nissan we have a difficult time keeping up. Can you imagine what the average work on anything shop has to suffer.

We buy over $1 million per year in Infiniti parts from a single dealer so you can be assured we get our questions answered fully.

After any vehicle is 6 years old the technology is pretty well understood by those that specialized in the brand but be careful and be sure to quiz the technican before allowing him to trash or learn on your vehicle.