Help! Is my head gasket blown?
 

Just bought a 06 G35 Sedan, drove good first day then started to overheat. I read about the air in cooling system and tried to bleed out with spill free funnel. Never could get heater to push heat while in idle. Drove it around block and heater worked fine and temp gauge was normal. I thought problem was fixed and drove it about 75 miles with no problems then by end of day it was overheating again. I tried to purge radiatior again with funnel but after fans kick and thermostat opens up it begins to boil in funnel. The temp gauge is normal inside, still no heat coming out vents. Does the boiling mean head gasket is gone?
): :confused2:

Did u burp the system??

Well I attempted to "burp" the system with the spill free funnel but the coolant in the funnel started to boil up like in splash mode. I shut off the car and thats where I'm stuck. I heard someone say it's normal for the "boil" mode in the funnel and that you have to let it cool and do it again?

If you blew your HG, you will have water in the oil or oil in the water. Check the dip stick to see if it looks like a chocolate shake or if you find a brown scum in the radiator.


There is a vent to "burp" the system in the back of the air intake plenum.

Look on page CO-11

http://www.nicoclub.com/FSM/G35/Seda...5_Sedan/co.pdf

Yes I am aware of the bleed screw, I am right now in the process of jacking up the front end since I heard that will help. I changed out thermostat and mechanic said it can take a while to get all the air out. I just did not know that the excessive bubbling in the spill free funnel was a normal part of the purging process. He says once the air is out I should have heat coming from vents and bubbling will stop. We we see.

If your head gasket is blown, you will see white smoke (water vapor) from the tail pipe, and the coolant level will drop. From your description, your head gasket is OK.

O.K now I'm really confused. I started the burp process again with the funnel. (Bear in mind I changed thermostat so I know there is a good bit of air in there) The rapid violent bubbling stopped but it was still chugging bubbles after 50 minutes of idle plus revving motor. The bubbles would subside for a while then if I reved motor they would start again. It really never stopped bubbling and I just never heard of it taking this long to burp a system. I did get medium heat coming through vents and occassionally very hot but not consistently hot air. I ran out of time so I guess I will resume when I get back home. Has anyone experienced it taking this long to burp a system?

Yeah, its quite a pain to change the coolant on our cars. I drained my coolant and swapped in new hoses July 1st, and after 2 weeks of driving and bleeding the system, it still wasn't perfect, but much better and I finally had heat at idle.

Remember to have your temp turned up as high as it will go when burping the system.

So when you say it took you two week of driving and purging system did you drive it and then do process over? Should I try driving it and then put funnel back on or should I just keep it idling in driveway with the burp funnel? This is pretty anoying for sure, but if stops overheating and its not my motor I will be a very happy man.

Unless I mis-read something the funnel is not for burping the system. It merely allows you to re-fill the radiator with no added air so in theory the burping process would be shortened or alleviated. However, since you changed out the thermostat, you have a significant amount of air in the system that will need to come out. Keep burping the system using the bleed screw at the back left of the motor with the radiator cap off and eventually all of that air will come out.

Well by all means I'm not the expert in getting air out since this is my first experience with an air tight cooling system,but when you have lots of air in the cooling system the funnel is supposed to serve as a way getting the air out way faster than the little bleed screw. The majority of people use the spill free funnel to "burp" the system by idling or revving the engine while in place. The bubbles come to the top of funnel and only coolant can get back in. Many mechanics that I read on line use a floor jack to raise the front of the car while doing this with the funnel (I'm going to try that today) I just never imagined that much trapped air in a motor. I will post on my progress since today I am doing another round in anticipation of getting full heat at idle and little to no bubbles in funnel.

Did you use an OEM thermostat? Did you replace the rad cap?


Outline of bleeding the cooling system:

http://x.infinitihelp.com/forum/loca...s.php?catid=25

Click on the mant. manual and go to page 14.

I would drive to work, let the car cool down while I was working, then at lunch or after work I would pop off the rad cap and turn the bleeder screw until I heard the air stop or until I heard the coolant rush down the line. Then I would drive home and do the same thing before I left the house the next day.

I just kept a little coolant kit with me behind the front seat. Coolant, small rad funnel, screw driver and rag.

I did use O.E.M. thermostat and I have a new cap. When the funnel is 1/3 full and car is idling I get only a few bubbles and only warm air through vents. When I rev the engine to like 2-3K I get some bigger bubbles and I get hot air coming out vents. When I go back to idle the bubbles subside and vent air returns to warm instead of hot. Going to try advice above and drive it a while then try relief screw to see if that helps.

When you drive the car now, does the coolant reservoir level go up or down after driving it for a while?