Lord Shogun

specs: 2007 350Z VQ35HR 62,000 miles.
Runs full synthetic fluids, just changed 1500 miles ago. Only use premium gas. Never drive on the highway. Live in TX, currently 100 degree weather.

I've looked all over the internet and cannot find a problem like I am having.

Started few days ago:
Got hot (didn't overheat), got home, check reservoir, empty, filled up.
Was fine next day. Day after, got hot again (again didn't overheat). check reservoir, was at max line. Read about needing to bleed.

I bled several times, on a 45 degree incline, got lots of air bubbles out.
Fed it a little bit of coolant, drove home, still getting hot.
Bled again and again, to no avail.

Finally went ahead and replaced thermostat. Bled it again several times. Filled coolant up to the neck on the top fill. Reservoir at max, never dropped while bleeding.

Drove home yesterday, still getting hot, but again not overheating, I've never received an overheating warning light or anything, but the needle is all the way up, one more tick and it will give the warning lights.

Got home, reservoir is max, top and bottom and small radiator hoses have no pressure, take off top fill cap, no pressure, also no fluid, no fluid underneath car. I let it cool until the morning.

In morning I fill up with coolant into the top fill until its at the neck. Before getting in car, I check underneath car again to be sure. and there is a massive coolant puddle under car. Its leaking all the coolant out as fast as I can pour it in.

Notes:
The oil is full and healthy.
The coolant under the car is pure coolant, no oil mixture.
There are no leaks from the radiator, from the top, or bottom or small radiator hoses in the front.
There are no leaks from the new thermostat area.

I have not had the time to pull off the cover and see where the coolant is leaking from.

What what are any of you guy's ideas or thoughts?

Heater core hoses popped?
Heater core leaking?
Water pump cracked? (it cannot be a regular leak, it dumped 70% of a gallon of coolant out in 2 minutes)

Thanks for any information or similar experiences!

KornerCarver

iTrader: (2)

I am not aware of any warning lights to indicate overheating. If your gauge maxed out, I suspect you have overheated the motor. You might need to take your car to a mechanic to get the problem sorted out.

Lord Shogun

I am getting ready to take in to a mechanic later today, but I hate going in blind, I just don't trust mechanics. I need to narrow it down more, it could be the difference of a 900 dollar repair or a 200 repair.

Do heater cores leak on 350z's? Can the hoses back there pop off?

Cux350z

iTrader: (162)

first thought is a blown HG allowing air to get into coolant system
2nd thought is the oil cooler coolant lines may have burst
3rd thought is the heater core lines may have burst

As you pour coolant, have someone watch where it is coming out. There are coolant pipes that are all around the motor. A cracked radiator, cracked hose ect could all be the culprit.

Cux350z

iTrader: (162)

Also your reservoir should be vented with a small hole/downspout. That would allow coolant to escape

eZg

iTrader: (5)

Until you locate the leak it's kinda hard to diagnosis.

My Bet would be air in the coolant...these suckers are VERY hard to bleed.

Second I would check to make sure your coolant fans are working.

Both of these would have coolant overflowing from the overflow downspout.

gl

eZg

iTrader: (5)

Any diagnosis yet?

I have been fighting overheating for a year now.

While it DOES sound like you have a leak somewhere....as opposed to air in your coolant or boiling/overheating coolant.

There could be an air pocket preventing the Thermostat from opening.

Are your fan's both working?

sportbiketed

iTrader: (11)

Bad radiator cap?