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-   -   ? about 2012+ cooling system (http://www.the370z.com/engine-drivetrain/89062-about-2012-cooling-system.html)

Owen 04-20-2014 12:09 PM

? about 2012+ cooling system
 
I have a 2012 that appears that the car wont build pressure in the cooling system. I would take it for warranty work, but I'm afraid they wouldn't fix it under warranty (I had the radiator replaced due to failure and used a csf).

This started with the occasional smell of coolant. While looking for the source, i noted that the water level was low. It was also noted that the techs who installed my radiator had swapped the high and low coolant pressure caps (high pressure cap on the overflow bottle), which I installed the correct way.

This progressed into noting that the coolant level was low every time I drove it. I never noted coolant dripping from car, but given the volume of water that was going through the engine I figured there should be a visible leak. On first run through I coulnd't find one, but while scratching my head on what to look for next, coolant started gushing out of the bottom. It was quickly traced to the overflow tank. Over the course of the 6 minutes or so, the fan would cycle. When the fan was off, the overflow level rises, when the fan was on the level would drop. After a few minutes, enough coolant is blown out that the leakage stops.

Mystery 1 solved. It wouldn't start losing coolant until a couple of minutes after start-up and would stop after 10 miuntes or so. No apparent puddles or leaks, but lots of cooant loss.

With volume of the breathing, I checked the firmess of the hoses. Nope. They were cold squishy. Brand new factory radiator cap goes on, and the bleeding starts. Except it never bleeds. Front end up in the air. Drivers side air cleaner off, radiator bled. Over the course of a week, numerous hot cold cycles, heater on/off and a couple gallons of coolant. The behavior is still the same. Lots of expansion during warm up (which blows coolant out) and lots of contraction during cool down and no apparent firmness of the lines.

During one of the cold starts, I was filling the high pressure side and noted that the fluid level in the overflow tank was rising too. On a hunch, I disconnected the overflow line from the high pressure cap to the tank and started it up. Lo and behold, not one drip of fluid comes from the cap during warm up, but the expansion/contraction cycke of fluid in the overflow tank persists.

Mystery 2 solved. The cooling system is not building pressure. This causes excessive coolant expansion which the overflow tank was not designed to contain.

Myster 3 solved. With the line on the top of the overflow tank disconnected, there is only one path left - the line from the bottom of the overflow tank to the heater line. So the flow MUST be from the heater line.

This is where I am stumped. In studying the 2012+ coolant system there is no apparent way for it to be a pressurized cooling system. According to the schematics, the overflow tank (typically low pressure) is connected directly to the heater tube (typically high pressure). What am I missing? Is there supposed to be a check valve somewhere? Why is there even this second attachment to the heater tube?

Ideas?

O

gbrettin 04-20-2014 02:33 PM

Why not at least ask the dealership about the warranty instead of assuming they will say no? Worst case scenario they do say no.

Jordo! 04-20-2014 02:48 PM

It needs to be bled -- there must be air in the system and/or a leak.

DEpointfive0 04-20-2014 03:36 PM

Is the high pressure cap on the reservoir now?

I'm a tad confused

Owen 04-21-2014 12:55 AM

I'm getting close to asking the dealer, but I've had VERY bad experiences with them in the past. I assure the worst that can happen is much worse than them just saying no.

There is no way to bleed the system, as it wont hold pressure. But where is the "leak"? It is not a leak in the sense of hey look there's water coming out from this part where it isn't supposed to.

The high pressure cap is where it belongs, on the gooseneck coming out between the cylinder banks. The overflow tank has the low pressure cap.

Just to be clear, the 2012+ is significantly differt than the earlier models.

O

DEpointfive0 04-21-2014 01:03 AM

Quote:

Originally Posted by Owen (Post 2788822)
I'm getting close to asking the dealer, but I've had VERY bad experiences with them in the past. I assure the worst that can happen is much worse than them just saying no.

There is no way to bleed the system, as it wont hold pressure. But where is the "leak"? It is not a leak in the sense of hey look there's water coming out from this part where it isn't supposed to.

The high pressure cap is where it belongs, on the gooseneck coming out between the cylinder banks. The overflow tank has the low pressure cap.

Just to be clear, the 2012+ is significantly differt than the earlier models.

O

Great. That's the problem.


You need the flat cap on the "gooseneck"
You need the cap with the spring on the reservoir.

BlueDemon 05-04-2020 11:13 AM

Hey dude, so I have the SOHO oil catch can/coolant reservoir, and I am having a leak out my dump tube. Car had some bubbles, ran the car, topped it up, got the bubbles out. Went for a drive, got on heavy throttle, and smoke came spewing out, coolant sprayed out the dump pipe all over headers and all that. Not leaking form anywhere else, caps are on right. Question is, should there be coolant visible in the gooseneck area when the car is cold? Car was dyno tested last year, no leaks no issues. And I notice my temp does go up a bubble or two then my fans come on, trying to figure out what the F it could be.

OptionZero 05-04-2020 12:30 PM

Did you get the right version? There are pressurized and nonpressurized versions

redondoaveb 05-04-2020 12:50 PM

Quote:

Originally Posted by OptionZero (Post 3931790)
Did you get the right version? There are pressurized and nonpressurized versions

SOHO had issues with the pressurized version and only sell the non-pressurized. That is unless they fixed the issue and are selling the pressurized again.

BlueDemon 05-04-2020 02:16 PM

I got the pressurized one just last year and spoke to Nik yesterday. He didn't mention anything about it not being the right one or issues with it. I know for certain that its coming out the dump hose. No other leaks anywhere else, no pinched lines, nothing. I ran the car got the bubbles out, then went for the cruise and all that happened.

OptionZero 05-04-2020 02:43 PM

I bring it up because 2012 was the year that they changed from non-pressurized to pressurized in that coolant system

i dunno if thats your specific issue though

SonicVQ 05-04-2020 02:53 PM

Quote:

Originally Posted by OptionZero (Post 3931808)
I bring it up because 2012 was the year that they changed from non-pressurized to pressurized in that coolant system

i dunno if thats your specific issue though

I think you meant to say "2012 is the start of the pressurized expansion / overflow tank"

Cooling systems have been pressurized almost forever :)

BlueDemon 05-04-2020 03:08 PM

Yeah off their site I ordered the pressurized overflow tank, so I got the spring loaded cap for that, no issues there. Mind you, I am also on the Topgunz air to air kit, and running the csf race rad, so would the oem rad cap still be efficient?


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