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I had a tough time with my cooling system when I bought my 2010 earlier this year. I replaced a leaking radiator and couldn't get proper heat from my vents. I ended up having to flush my heater core directly because it doesn't really get flushed forcefully enough with a basic cooling system drain and fill. If you've run your engine for 30m with a spill-free funnel connected and you still don't get HOT air from the vents, I'll bet your heater core is partially clogged like mine. I flushed mine into a bucket and posted pictures of the sediment that came out of it. It's much better now but probably not perfectly clean. I documented the air temp coming from my vents before/after the heater core flush and compared to my other vehicles. I included some pictures of where I disconnected the heater hoses because it's too hard to do it at the firewall.


Sounds like you're doing it right to me. I don't understand why the coolant would want to gush out if you were only revving to 2000. Mine would sort of percolate in the funnel a bit but barely splash out and I revved it significantly higher than 2000. Your cooling fans should cycle to keep things in a normal temperature range and the coolant will only expand so much. If you just stopped revving the engine (not shut it off) I would imagine it would not continue to gush out if everything is normal.
 
The liquid in that funnel looks like orange juice and it appears to be boiling. The vents not blowing hot air with the heat on while bleeding the system suggests air pockets in the heater core. I would suggest disconnecting the heater hoses and running water through the heater core to see how it flows to rule out a possible obstruction within or just do a force flush as @jbarnett250 suggested. If that checks out o.k. then possibly proceed with more system flushing, but it seems like there may be a flow problem somewhere.
 
Discussion starter · #23 ·
Going to do the force flush, b any chance any of y'all know the Inner Diameter hose I'd need for the heater core? I saw in @jbarnett250 post he used a 3/4ID but it also doesn't seem like he did it directly at the HC. Also, he has a 2010 not sure if it'd be the same exact as a 2007. Thanks.
 
Discussion starter · #24 ·
I drained the radiator and I was able to get a hose connected and flush out the heater core definitely a lot of stuff came out. I tried to fill the heater core with coolant after the flush but was unable to. I connected everything back together and added coolant and it seemed to fill up with less fluid than I remember. Started the car and when I revved the engine I couldn't rev past 1500rpms had no power and I got a few dtc codes that came in P0221/P0123 and P0223 if I recall. Didn't have time to asses much will check tomorrow. Anyway trying to purge the system of air the coolant eventually shot out through the funnel. I guess my biggest worry right now is we will probably get freezing temps tonight and the heater core has water in it. GG
 
That's interesting. Those codes are related to the accelerator pedal and throttle position sensors. That's definitely the kind of thing you can monitor with your obd interface. You can monitor both accel pedal sensors and the commanded throttle position and the measured throttle position to see what doesn't match up right. If something doesn't correlate, the car isn't certain where your foot is or where the throttle plate is which is a bad thing. I wonder if the jerky behavior you felt was originally related to the pedal/throttle issue?

As far as filling the cooling system after the heater core flush, I couldn't fill the heater core directly with coolant without making a huge mess so I didn't even try. I blew as much of the tap water out of the core as I could with my lungs. Then reattached the hoses, then filled the cooling system like normal. I forget if it was the manual or a diy I read that said to fill it really slowly (like 1 gal/min) to avoid trapping more air. I recall needing about 2 gallons of coolant to fill my system and reservoir. after the flush. I don't understand why there's so much pressure in your cooling system that it can shoot out if there's nothing to contain the pressure like a radiator cap. Hopefully you had enough coolant in the system to avoid a freeze up. That wouldn't be good.
 
Started the car and when I revved the engine I couldn't rev past 1500rpms had no power and I got a few dtc codes that came in P0221/P0123 and P0223 if I recall.
Those are all throttle position sensor codes. If you unplugged it, did you make sure to plug it back in?

I drained the radiator and I was able to get a hose connected and flush out the heater core definitely a lot of stuff came out. I tried to fill the heater core with coolant after the flush but was unable to. I connected everything back together and added coolant and it seemed to fill up with less fluid than I remember.
If there was a lot of "stuff" in the heater core then that stuff has probably made its way to other parts of the cooling system. Did debris come out of the radiator when you drained it? If so, try disconnecting upper and lower hoses from the radiator and do the same hose flush through the top of the radiator and see if a lot of junk comes out too.

BTW, what does this debris look like? If you really have that much garbage circulating through the cooling system, I'd be tempted to pull the thermostat and see if it's loaded with crap that might be restricting flow through it (...might require a new gasket). Below is a schematic of how the coolant flows through the system and it goes from cylinder head -> radiator -> thermostat -> water pump so if the thermostat is gunked up then that may explain why the coolant level is rising so high and so quickly in the funnel. It could also possibly explain the gushing when revving the engine if the water pump is trying to push coolant into the radiator at high volume but it can't flow quickly enough through the thermostat so the excess pressure gets vented out the radiator neck into the funnel. Just a theory, FWIW.

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Discussion starter · #27 ·
Those are all throttle position sensor codes. If you unplugged it, did you make sure to plug it back in?
Yep, i did plug it all back and checked. I probably should have disconnected the battery. I forgot with Nissan there's a lot of idle relearn and other things. i'll try pulling the thermostat to see how it's looking i believe that's easy and i'll try to flush out the radiator directly. i did take a pic just forgot to add it.
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Regarding air pockets. I heard that Infinit V6 engines have a reputation for being difficult to burp the air out of the heater core. Same engine as us I believe. The method he mentioned was they vacuum the cooling system of air, then suck in the coolant. Sounds effective, but I don't think it's a DIY type of thing...

But in this thread, it's crud gumming up the system that is causing the issue...
 
Looks like I'm going to need a new therm View attachment 57362
ostat
That is the coolant temperature sensor. But, yes, that's broken.

Thermostat is on the cylinder head near where the serpentine belts are. You said you replaced that, correct?

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Yes sorry it is the coolant temp sensor and yes I replaced the thermostat with the housing and the gasket OEM from Nissan like 3 months ago. And the throttle body was disconnected
O.K. That's what I meant about pulling the thermostat housing and seeing if there's gunk in there too.

Were the cooling fans coming on at all while bleeding the system?
 
Discussion starter · #33 ·
O.K. That's what I meant about pulling the thermostat housing and seeing if there's gunk in there too.

Were the cooling fans coming on at all while bleeding the system?
yep, they were. if i recall the old thermostat housing had gunk in it. honestly i don't want to pull the thermostat housing again to check it was quite a pain and big hands do not help and u-joints weren't really helping either but was eventually able to get the new one installed. removing the hose that goes to the bottom of the radiator there was a lot of red flakes on my hands from it so not sure.

but if i need to remove it again i guess i will just have to.
 
If you saw gunk around the thermostat and red flakes, I am concerned that there are deposits which are limiting the amount of cooling. Given the red flakes, I'm wondering if there were incompatible types of antifreeze used in that engine, causing deposits.
 
Discussion starter · #35 ·
Maybe or improper care to it. I just connected a hose which heads towards the heater core I left the radiator drain plug off and the bottom hose disconnected. Water was coming out of both locations and water was coming out of the thermostat housing hose as well
 
Discussion starter · #36 ·
Alright tried flushing it again with the coolant flush system and distilled water. Think still clogs somewhere. Reservoir was about to fill to the top. So not sure what else to do or try and still have loss of power and throttle body is connected again.
 
I'm struggling for ideas. I'm also wondering if the radiator is flowing OK.

Have you tried disconnecting the top and bottom hoses and running water through the radiator to see if it's flowing OK?
 
Discussion starter · #38 ·
I'm struggling for ideas. I'm also wondering if the radiator is flowing OK.

Have you tried disconnecting the top and bottom hoses and running water through the radiator to see if it's flowing OK?
I haven't tried that I can give it a shot. I'll try it tomorrow. think my biggest concern was not leaving water in the system to potentially freeze overnight. I still have possibly 2 more hours of daylight but I can start it early tomorrow.

I was able to bleed the system of all liquids I believe. I used those coolant service kits and used my data vac (pushes and sucks air) to the hose connector on the coolant service kit and essentially watched all the liquid shoot out of the bottom of the radiator until there wasn't any. I set it up so it should have started at the heater core first. but I will try to see if the radiator is flowing properly tomorrow.

If the radiator is not flowing properly then I should replace it or just try to fix its flow issue I guess first.

And thank you all for all your help so far. my biggest worry was leaving water in the system so since that's gone i can let it sit for a bit if i need to.

my mechanic friend linked me to this kit Amazon.com: Coolant Vacuum Refill Kit Time-saving&Well-sealed Cooling System Vacuum Purge & Refill Kit with Accurate Pressure Gauge, 4 Sizes of Adapters, Brass Connector,Long Coolant Filling Hose for All Vehicles : Automotive

Said i can give it a shot, should essentially suck the air out and force the coolant in so i don't have to bleed it.
 
yep, they were. if i recall the old thermostat housing had gunk in it. honestly i don't want to pull the thermostat housing again to check it was quite a pain and big hands do not help and u-joints weren't really helping either but was eventually able to get the new one installed. removing the hose that goes to the bottom of the radiator there was a lot of red flakes on my hands from it so not sure.

but if i need to remove it again i guess i will just have to.
Given all that you have been doing, and even though it may be a pain, I think you should remove and check the thermostat again...

If the temperature is only briefly reaching the freezing point, I don't think it will be a problem. I think it would take a sustained overnight hard freeze to be a concern. Maybe through a blanket over the hood would help...
 
Discussion starter · #40 ·
Given all that you have been doing, and even though it may be a pain, I think you should remove and check the thermostat again...

If the temperature is only briefly reaching the freezing point, I don't think it will be a problem. I think it would take a sustained overnight hard freeze to be a concern. Maybe through a blanket over the hood would help...
Just pulled it. Looks relatively clean aside from the auxiliary port? But yea some little red flakes in the corner but overall looks fine. Going to boil it and make sure it opens before I install it back. I also did disconnect the upper and lower radiator hose and pour water didn't seem to be any radiator blockage or flow issue.
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