2012 QX56 Potential Blown Head Gasket

[mklemp]

My QX56 has logged 80,000 miles and I took it in for an oil change. It's been running great with zero overheats.

The service technician opened the hood to remove the oil cap and the radiator overflow port broke off.

The port was brittle, I repaired it and took the opportunity to perform a coolant flush.

The vehicle is now pushing coolant out the overflow and I assumed that I had failed to remove all of the air during the flush and burp process.

I attempted another burp process to remove any trapped air and it continued to produce bubbles after 90 minutes and reving the engine made it worse.

Next step is to perform a combustion leak test.

I'm a bit surprised to be dealing with a head gasket issue at 80K miles.

Is this a common problem with QX56/QX80s?

[mklemp]

Good news...no exhaust gas in the radiator.

I'll be using a coolant vacuum to remove the trapped air in the system.

[marquesjw]

I was having a hard time getting all my air out of my system, apparently our old armadas can let air get sucked into the system with the old hoses. Something about the heater core as well.

[VStar650CL]

Just about everything Nissan is hard to bleed, the VK56's are no exception. The best DIY solution without vacuum is a no-spill funnel and either a very steep hill or jacking the front end about 2 feet. Run it at 4000 RPM for about 2 minutes and it will purge successfully about 95% of the time. We have a hill with a 21% grade about a block from our dealership, I used it a lot in the old days.