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Hello everyone, I'm searching for some guidance to hopefully correct a larger problem from occurring down the road (no pun intended ). Recently, I've been hearing what sounds like water sloshing around behind the dash on the passenger side of the car. My research led to me believe that it's either air in the cooling system or a possible blockage in the A/C condensate line. I'm in the process of checking the cooling system & have not seen any leaks, cracks in the radiator hoses, or noticed any drop in performance. The car does not overheat & the temp gauge is right where it should be. After researching a bit further, I decided to check the heater hose connector since that particular part seems to fail at a certain point. I've attached a photo of mine & was wondering if there's anything to be concerned about? My car is approximately 10 years old with 118k miles on the odometer.
Replace it. Just do it. My 2011 looked fine. But I wanted to replace it preemptively and I'm glad I did. As soon as I tried to remove it from the hose it just sort of crumbled into about 20 pieces. It's a ticking time bomb.
Recently, I've been hearing what sounds like water sloshing around behind the dash on the passenger side of the car. My research led to me believe that it's either air in the cooling system...
That is exactly what that "sloshing" noise is. When the engine is hot, coolant is slowly seeping from the doomed heater hose connector as a result of both pressure and liquid expansion. Conversely, as the coolant cools down and contracts, this creates a minor vacuum which can draw air into the system. Over time it adds up.
Heed everyone's advice: replace the connector with a metal one and properly fill & "burp" the system without delay.
Last edited by ILM-NC G37S; 04-05-2023 at 10:22 AM.
A huge thank you to everyone who replied. It seems the unanimous decision is to replace the heater hose connector. I'll have to find a 3/4" fitting from the hardware store since I'll be traveling this weekend & can't risk having something shipped due to the time constraint. On top of this, my fuel gauge decided to stop working! It goes down to the halfway mark & stays there. That will have to wait for now, I'll keep you guys updated.
Just a note on the temp gauge. MotorvateDIY discovered with his upcoming GTR gauge update, the coolant temp gauge in the dash has a smoothing correction of like 25 degrees. By the time it starts to show too hot, may sometimes be too late. Its very inaccurate, but if Nissan showed true temps at all times, it would jump up and down 15-20 degrees every few minutes and people who don't know better would freak out.
My car is nearly 10 years old and I never had any issues with the passenger side OEM plastic heater hose connector. However. I proactively replaced recently based on the frequent posts here on the community and in the G37 Reddit forum.
I used this 3/4" metal connector from Dorman and some standard hose clamps from Home Depot as the OEM spring clamps are somewhat difficult to use based on the location of this hose (may also break as they are not intended to be reused).
I was surprised that very little coolant came out of the hose once disconnected. Nonetheless, I bled and topped off with my trusty Lisle spill free funnel once complete.
One thing to note is that the OEM connector will be extremely brittle and disintegrate if you tug on it too hard with pliers. As such, I began that way, but then transitioned to using my hand and gentle twisting as I didn't want any more of the connector to break off and potentially fall into the cooling system.
My car is nearly 10 years old and I never had any issues with the passenger side OEM plastic heater hose connector. However. I proactively replaced recently based on the frequent posts here on the community and in the G37 Reddit forum.
I used this 3/4" metal connector from Dorman and some standard hose clamps from Home Depot as the OEM spring clamps are somewhat difficult to use based on the location of this hose (may also break as they are not intended to be reused).
I was surprised that very little coolant came out of the hose once disconnected. Nonetheless, I bled and topped off with my trusty Lisle spill free funnel once complete.
One thing to note is that the OEM connector will be extremely brittle and disintegrate if you tug on it too hard with pliers. As such, I began that way, but then transitioned to using my hand and gentle twisting as I didn't want any more of the connector to break off and potentially fall into the cooling system.
I appreciate the good advice my man! I just picked up a 3/4" brass coupler from Home Depot & will be tackling it this weekend (hopefully she'll hold til' then). To be completely honest, I'm not entirely sure how to bleed the system. I understand the concept but have seen a dozen different ways on how to do it. I may just have my mechanic do a complete coolant flush next week when I get back to be safe.
This is great, thank you providing it. In short, you basically add coolant to the funnel with the car running (heat on full blast) & wait until the bubbles disappear/ air disperses correct?
This is great, thank you providing it. In short, you basically add coolant to the funnel with the car running (heat on full blast) & wait until the bubbles disappear/ air disperses correct?
Coolant funnels can be found for $20-$25
For coolant, Autozone sells blue in concentrate which with the amount that you'll leak you can fill with concentrate and the engine will mix it with what it has. A slightly higher coolant concentration will slow down leaks and raise the boiling temp of your coolant (which is good) at the same price as the nissan 50/50. You could even mix it yourself at home and save $15 being that you'll end up with 2 gals of 50/50 once mixed.
For the process, place the heater on 90F at low speeds and not high. Why low?
The heater acts as a mini radiator so at full blast you'll end up doing cooling prior to thermostat opening.
Now these cars do not have a heater flow valve to stop the flow, flow is always happening so regardless if the heat is on or not it will still cycle through the entire system.
Install the funnel, insert coolant slowly to avoid inserting bubbles in this process, once you start seeing coolant floating in the funnel, start the car and proceed to keep adding.
Add slowly while keeping the bottom of the funnel under coolant, whenever you start seeing bubbles slow down, start squeezing hoses to help these bubbles come up.
Once the car start warming up keep a minimum amount of coolant in the funnel, why?
Once the car warms up the coolant, levels will start raising a lowering at the opening of the Tstat and if you have a 1/2 way full funnel you WILL spill once the thermostat opens and closes.
Once you dont see any more bubbles and are satisfied, turn off the car and keep the funnel with coolant. Let the car rest for an hour, you'll see that most of the coolant in the funnel will have entered the engine.
Top off the reservoir and place the cap and you're done.
I wanted to check back in & let you guys know that I managed to complete the repair this past weekend (albeit not without struggle). In my head, I thought this would be a 1 hour job tops but boy what I was wrong! It ended up taking about 3 hours due to the plastic connector breaking apart while trying to remove it from the hoses The connector & hoses were fused together so tightly which made separating them extremely difficult. Along with very little room to work, I was left with bloodied hands & sad ego lol. I used a 3/4" barbed, brass coupler as a replacement from Home Depot & it worked perfectly (linked below). As you can see in the first picture, I was not able to remove one of the existing hose clamps. It refused to slide off the hose & I decided to leave it for the time being... In the second picture (taken a few days after), I was able to slide it all the way down the hose & butt it up against the clamp near the firewall thanks to the tool in the link below (dedicated hose clamp pliers). If there's anyone considering to attempt this repair, I cannot stress the importance of this tool. Learn from my mistakes/ misery & have one of these on hand before you even pop the hood. Regular pliers do not work well on these spring clamps & the amount of room you have to work is very minimal.
* On a side note, I also managed to put in the new HVAC module behind the dash & finally have an accurate fuel gauge again. Thank you to everyone who chimed in. I'll be bleeding the system this weekend since there still appears to be air trapped somewhere.
Agree that the OEM spring clamps make this job much harder than it needs to be as those clamps seem to fuse themselves to the hose.
I broke the one you show that needed to be slid down next to the other clamp near the heater core.
Technically, they are not designed to be reused, but many reuse nonetheless.
If I was to do this job again, I'd likely buy some pinch pliers: https://www.harborfreight.com/line-c...ece-63596.html as you wouldn't have to worry as much about tiny pieces of the plastic coupler falling into the cooling system.
04-04-2023, 01:47 PM
). Recently, I've been hearing what sounds like water sloshing around behind the dash on the passenger side of the car. My research led to me believe that it's either air in the cooling system or a possible blockage in the A/C condensate line. I'm in the process of checking the cooling system & have not seen any leaks, cracks in the radiator hoses, or noticed any drop in performance. The car does not overheat & the temp gauge is right where it should be. After researching a bit further, I decided to check the heater hose connector since that particular part seems to fail at a certain point. I've attached a photo of mine & was wondering if there's anything to be concerned about? My car is approximately 10 years old with 118k miles on the odometer.
