I have searched and seems a lot on either bleeding the system or the car running hot/over heating. I'm having an issue getting the Tstat to open. I did the bleeding procedures several times. Start car let warm up. Car warms up and fans kick on and don't shut off. Car stay at normal operating temp with hot heat. Top hose is hot and bottom is cold. Stat not opening right? So, take the stat out boil it in a pot. It opens. I put it back in the car and do it all over again. Same thing!!!! Bottom hose cold. Car isn't running hot. I have heat etc. idk what the hell is going on. I just don't get it. Car runs for a while and stat not opening but it don't over heat? Weird. Anybody?

 

If the Tstat is not opening the engine will overheat, it seems that the Tstat is opened. In the temp gauge what the reading?

 

Reading normal operating temp. Bottom hose is ice cold. Top hose is hot. If it were opening you would think the lower hose would be hot or at least warm. Right?

 

Did you delete any of the factory coolant piping like the stock oil cooler/warmer and the bypass across the front? The system needs enough bypassed flow to warm up the tstat so it opens. I've done those deletes but my turbos are in parallel with the cooling loop (and each other) so they make up about the same amount of flow as the bypass. Other trick is to drill a hole in the stat to get some bypass flow.

Try this, turn the heater on full (fan low to mid), start the car and let the engine warm up. With the heat on the heater core should bypass enough flow to get the stat open. Check your lower hose to test. The temp reading in the car assumes normal flow past the sensor in the hard pipe, without flow the motor may be a lot hotter than the gauge.

 

Yes I did all them deletes. Never had this issue on last build. This is a fresh build. My turbos are oil cooled. I also did all of what you mentioned and still the same. Ugh. That's what I'm worried about. The temp of motor being higher then the sensor is reading. I'm going to hook up laptop tomorrow and use Uprev to see what the actual temp is reading from the ecu. Idk I'm lost. And stressing!!! Fresh build = a lot of money 😟😟😟

 

Isn't it possible that you have an air bubble preventing the coolant from reaching the T-stat therefore keeping it from opening?

Only way to fix such an occurrence, that I could think of was,

1) Pour coolant in slower than sheet as you fill up the radiator.

2) Squeeze as many diff hoses while running it with lisel (sp) funnel.

3) of course front end elevated as well as all the other crap like heat on, bleeder valve procedure, etc, etc,

Good luck Man.

 

Thanks man. Yes very well could be a air pocket right behind the stat. I'm gonna give it another shot today. What has be baffled is the fact that it's not over heating. At least that's what gauge says

 

No luck today again. Did the whole process over and nothing. Lower hose ice cold along with the whole bottom half or the rad. Took stat out boiled it three times. Working fine. Took the stat off the housing and ran it with not stat. Everything seemed to be fine. Lower hose got. Rad hot. Fans cycling on/off like they should. Had heat soon as I burped the air from bleeder. Seemed to be running fine. I have a new stat coming tomorrow so I will put in and do it all over again. The car is up on all 4 jack stands I'm also going to lower the rear of the car so front is up as high as I can get it. Driving me crazy!!!!! Also just don't want the car to idle for real real long. Fresh motor, I want the rings to seat properly.

 

I know there is a lot of write up about this but I just want to post up what I did and what seemed to work for me. Hopefully this to will help someone. This cooling system can really make you nuts. So I got the stat to open. I replaced with new nismo, filled system like the manual says. I also this time raised the front end. Started the car. I let it get up to temp and still was doing the same thing. No heat and started to run hot. I shut off let cool down. I did run and get new rad cap for a piece of mind. Topped off coolant. Started back up. I let it warm up and had no heat. Started to climb in temp so I cracked the bleeder and heat started to get hot. Cracked again to get more air out and boom state opened. Hope this helps someone.

 

I'm still a believer in pouring the coolant super slow. Squeeze hoses midway and towards the end. And yes the bleeder valve as well.

I even went through upgrading fans and throwing radiator caps and everything else I could think of.

Well enjoy it man!

 

Thxs bud. Yes very slow. Slow to the point my arm was killing me from holding the damn coolant jug. Lol

 

And the stat starts it's s**t again!!!!����
Put the car on level ground ( idk if that's it) and not opening AGAIN!!!
I'm over it. Idk what the hell is going on!!!!

Starting to wonder about the water pump!!! Idk just thinking of what other things could cause it. Also idk maybe air still in there? I cracked bleeder and no air. I'm lost!! Oh and I'm furious!!!!

 

I bet it's another air bubble. But that does F'ing suck.

ARe you keeping an eye on the coolant reservoir? When the engine cools down it tends to suck air in if the level is too low.

 

Yes reservoir is full. Idk man. Hope it's just air and I get it out. I'm think pump isn't circulating the coolant now. Smh. I know it's a long shot cause it's ran off timing chain and it's pretty much new. Idk man

 

Are you using a Lisle type spill-free funnel for your radiator/coolant?

 

Did all that. Just boiled over. More of a mess then good.

 

Mine boiled over as well.......multiple times before a new Tstat solved my issue.

it's almost as if the hose going to the Tsat needs a bleeder valve. Looking at it you can see it is a perfect place for air to gather......

 

Yes I know

 

drill that hole!

if you want my OEM (non-nismo) let me know...

empty out your reservoir ... that's only for overflow!

 

I jacked the front end up again and let it run. Got it to open again. I shut the car off and let it cool down. Topped it off and started it up again and let it get up to temp. Opened once again. I did let it run for awhile seemed to be working ok again. I had to run and take care of something so I will give it another go around next time I'm there. Crossing my fingers!!!