Hey guys,
First off, sorry for the novel. I figured details help in diagnosing other peoples problems….. the more the merrier?

I normally don't make new threads; and I try to search the forum as much as possible, as searching usually provides the answer to everything. Tonight however, it was a little more difficult to piece together solutions from other threads. That said, I believe I am on the right track, and just wanted to verify with you guys.

general background:
My car is a 2005 enthusiast model 350z, mods are primarily stance, bucket seat, sometimes a welded diff when I throw it in, and other random ish, but I do have exhaust and an K&N air filter… otherwise no engine mods. The engine has 98K miles on it, I change out the oil myself with legit expensive oil and oil stabilizer; and the engine runs very clean, and very very strong. *never ever ever saw the temp go over half way... like it ran on miracles… even after some skidpad drift days at the track.

Backgound problems:
About a year back I noticed my car would not blow heat when at a stop light; I used this forum to diagnose the issue as air in my coolant system. I didn't do much besides run the engine, check the coolant level in the over flow, and bleed the purge valve on the hose on the back/passenger side of the engine bay. Bubbles came out, tried opening and closing, on and off throttle, reopening etc… The car blew heat for a lot longer now at stoplights, but still eventually went cold. I figured it was 'good enough' for me.

Last week, my battery came to the end of its life cycle; had 12.6 volts but no more cold cranking amps… I replaced it with a new battery, and subsequently the car's ecu reset. I am not sure if this is exactly related, but it happened last week.

Current Problem:
So the car has been acting great, running like a f'ing champ, as usual. I drive home from work, no problems at all. My wife and I decide to go to eat out, so we leave. I drive for about 3 mins, and get on the freeway, and turn on the A/C to max as my wife likes it cold.
About 2 mins of freeway driving, at steady speed of 73mph, no hard throttling, no off throttle, just steady speed. Suddenly I hear a 'burp' sound, cars throttle goes limp, (i am assuming its in limp mode) SES light pops on, and some steam is coming out from the far front passenger side of the hood. (practically exactly where the overfill container is located in the engine bay.) I heard a weird feint 'wherring' noise, but I will touch on that later

I immediately exit the highway, luckily there was an offramp within 100 feet of the incident, pulled over, and rolled into a parking lot. luckily there was an O'Rielly's auto parts store right there! lol

I pop the hood, and check just to find 'splatter' of my radiator/water mix all over the front passenger side of the engine bay. However looking all over the engine bay, under the car, wheel well, I can't locate the source of the fluid leak. I assume maybe it burped out a bunch of fluid out of the small opening on the overflow tank?

I check the overfill container, and its pretty full, like 3 inches above the max line. O'Rielly people come out to see the smoking Z with the hood popped. They are nice and helpful, but they can't seem to help solve the issue. I don't blame them though, they are not a repair garage anyway. I started it back up for the O'Rielly folk, and give it some revs for diagnostics. The car is no longer in limp mode, and revs like its usual symphony of awesomeness.
As we all look over the engine for 25 mins, I notice the overfill container is now almost completely empty. I borrow about 1 qt of water to fill the overflow container, and the water goes straight in and dissapearrs into the coolant system. I attempt an extremely careful drive home. I live about 5 mi away, and stop twice due to seeing the temp gauge swing up towards HOT. I turned the heater on to relieve some of the heat… doesn't really help.

On one of the stops on the way home, I buy a huge jug of water from a gas station, as I pop the hood my overflow tank is now crazy full. Im like wtf? So I let it cool and drive carefully home.

Note that on the drive, I heard that repetitive 'werring' noise now and again, sometime stronger than others. I assume maybe this is a dry water pump? not sure there.

Once home, I park it in the garage, and check the engine again. Overfill container is still brimming with fluid. I let the engine cool, and come back later, all the fluid has drained back into the system.

I perform the flashing see code process, and pulled p1217 - engine coolant temp too high. well yea thats obvious i guess.

Possible Solutions:

Ok so from my research, I should probably do things in this order or different?:

1 burp the system
2 replace thermostat?

Or should I reverse that order? to save time and burping/coolant flush?

Or does this even sound like a thermostat problem? I don't know that much about thermostats. ...minus the fact that I know they open when the engine needs cooling and close when the engine is fine… ?

someone on another thread pointed out this helpful piece of wizardry, which I think I may be picking up:
Lisle 24610 Spill-Free Funnel
hopefully they sell it locally.

I am kinda lost, and looking to fix it myself. I was hoping someone could provide confirmation or some other tips, if so, I would be most obliged.

I have plenty of tools and have done loads of shade tree mechanic work on my car, but I have been spoiled by such a good coolant system that I am (embarrassingly) slightly ignorant to the full extent of understudying the coolant system. I know the water pump is death to DIY, so I am praying its not that lol.

Thank you all in advance for your help, and keep pimping like always.

 

I just had the same symptoms except for the overflowing with my z. My cooling fan burned out and since then the car kept heating up. Our cooling systems are pretty difficult to bleed. Look into the spill free funnel as thats the only way in my opinion to get the job done right! You could always do a thermostat test with some boiling water its not that hard to remove anyway, Best of luck to you

 

I would say, check your thermostat first and then burp the system.

Get some tests done to see how your cylinder head gaskets are doing.

Good luck.

 

+1...It's acting like you have a blown headgasket....my car was acting just like yours when I blew my headgasket...

 

Thanks guys for the input. I took today off work to investigate. I looked all over the engine, and couldn't find any coolant leaks around the head gaskets. I suppose they could be in worse shape now due to the heat of the engine.

I checked the fan, and that works great.

So far today, I have partially drained the coolant and now removing the thermostat from the engine.

When looking at the hose the thermostat connects with, it had lots of green crumbly corrosion around it. Maybe that points to something?

I plan to continue the removal of the thermostat, and when the wife gets home, see if I can go buy a new one and one of those leslie fill tool funnels for the coolant.

I have been reading a little more, could it have been possible the thermostat got stuck closed, and the coolant got hot, and backed pushed itself out the top of the atmospheric hole on top of the coolant overflow reservoir? I only ask cuz thats where all the coolant looks to have come from when it burst out on the freeway. ??

Thanks guys for all your help so far. Its definitely given me food for thought.

 

You should start with a hydrocarbon test on your coolant to see if you're getting any oil infiltration into the cooling system. It's very cut-and-dry. The test kit isn't that expensive.

 

:update:

So I got the new thermostat, and some more coolant from the store. I asked and called around for the leslie funnel or similar, and no store had any.

When I got home, I installed the new thermostat per the FSM. I let the car run, with the heater on, and had the reservoir cap open, the bleeder valve open and the radiator cap open as I filled it up. I was also massaging the upper coolant hose to make sure bubbles come out.

after about 10 mins the bleeder valve starts leaking out some fluid, so I go and plug it up, and as soon as I do, the radiator over flows at the top. I turned off the car and just let it chill for a bit.

The whole time the reservoir was at the max line, and never moved.

I guess I will try again to cycle the engine on then let it cool and try to bleed the system?

I also asked around for the hydrocarbon test kit, but no story carried that either.

I guess I will try again in the morning to bleed the system better?