Coolant level raising in Overflow

g0ldm4g3

g0ldm4g3

Would ya just look at it
iS VIP
Car
2006 FX35 RWD
Name
Nnaji
So, I get back home from taking my parents to the airport, then I open my hood to add oil.. and I see the coolant overflow tank is literally full with some coolant around the top.

TiGHDQj.jpg

What on Earth..? How..? and why did this happen? lol
 
Read that could be a thermostat problem... A search would probably show up more results... Did you ever figure it out?
 
Looks like it was the cap, did a compression test and sure enough it wasn't holding enough pressure causing a slow leak and irregular vacuum so that the reservoir was receiving more coolant

Sent from my SM-G935T
 
Last edited:
g0ldm4g3 said:
Looks like it was the cap, did a compression test and sure enough it wasn't holding enough pressure causing a slow leak and irregular vacuum so that the reservoir was receiving more coolant

Sent from my SM-G935T
Click to expand...

That is correct you need to replace your radiator cap BUT you need to get an INFINITI cap ONLY!! For some silly reason the neck on our radiators are deeper than a standard radiator cap. I own a repair shop and race shop and have never seen anything like it but I can tell you its true for sure. This problem can create air pockets in your cooling system causing an overheating issue and completely tearing up a perfectly running motor.
 
Hey Nnaji-

You can get the identical Infiniti radiator cap for so much less at a Nissan Dealership. This is what I did when I replaced my cap when we did our coolant flush together.


Sent from my iPhone
 
Hello guys,
I've been having the identical issue, I followed the advise bought an OEM cap (from NISSAN, thanx for that advise!). Unfortunately still having same issue. Step 2, I was advised to bleed the system. Check, seemed too help but after a road test, still back flowing and overheating persists. Step 3 is test the Thermostat, but I'm not confident this is the root cause as this had been replaced recently with a new Radiator. Anyone know how to test or more important how difficult to replace the water pump? Any and all advise is greatly appreciated. Getting frustrated and do not want to give up on the FX as she has lots of life left!
 
Rad cap - check.
Bled system - check.
Thermostat & rad replaced recently - screeeeeech!
Everything was fine until the rad & thermo were replaced? If this problem was there prior to the rad & thermo, well then the problem hasn't been fixed yet but if not, then there you go.
Just when you think the system is cleared of air. Either there is still air in the system preventing the thermo from opening, the thermo isn't opening because it's a pos (not likely) or there is a blockage occurring somewhere in the rad. If you drive around (not recommended while overheating btw) you'll notice the lower hose doesn't get hot. No circulation.
 
Move,
Thanks for the input. Yep, all was well prior, FYI 166,000 and change original miles. Full story, original thermo failed about 2 yrs. ago. Original rad inlet neck literally fell apart in feb. 2018, there ya go. Upper/lower hoses another thermo just cuz, and rad repalced. Drove her from SoCal to Houston, TX last month pretty hard and she tapped out 500 miles short. I've been battling to heat ever since. I thought about the possibility of a hidden bubble too, hoping it's nothing more sinister. Thoughts?
 
If you're able to drive that much, I highly doubt there could be ennough air in the system to cause an overheating issue.
If you're able to drive without overheating after a coolant change or any such related b.s. where air gets in and must be bled, then for sure the lower hose would be hot because you have circulation. The system will burp what's left drawing coolant from the overflow tank.
You've ruled out the rad, thermo and rad cap, my next move would be the fans. Are they working? Take care of that FX fish. They're dying daily!
 
So I had the same problem. My car would actually over heat when it was over 95 degrees outside. I have over 200k miles on my fx. So what i did was changed the radiator because that thing was dirty when I took it apart. I also changed the radiator fan because I noticed while taking the radiator out that the locking clip on the mount was broke. I flushed out all the old coolant fluid and replaced it with infiniti radiator coolant and distilled water. I also replaced the hoses and thermostat. It sounds like a lot but my car runs much better and no more overheating. Here is a video on how to do a coolant flush on our engines. GOOD LUCK!

.
 
Update: Travel has limited my time to dedicate to the FX, so turned her over to an independent mechanic. Block test uncovered a blown head gasket. @$&%!!
So really only 3 options.
1) Repair - estimate $4,000+++ not recommended by mechanic, hmmm...?
2) Replace with Rebuilt - estimate $8,000+++ not the best financial decision
3) Replace with Used - estimate $3,700+++ recommended by mechanic
Thoughts anyone? thinking also about a second opinion, anyone know of a solid Infinti Mechanic in Katy, TX area
All thoughts, ideas, etc. are greatly appreciated.
 
Is there coolant mixed with oil?
If it is a head gasket, the question is why did it fail. Is the head or block warped or did the gasket just give up. There may be a solution(?); replace the gasket, head bolts and use a permatex sealant in case of warp issues. You got to do a little research. Also, a performance shop familiar with the VQ might be a better route to take. They tend to be much more competent.
 
Oh, and one more thing. You had the rad & thermo replaced recently. If it wasn't overheating prior to these replacements and now you've got a blown head gasket?
Shops fault.:tdown:
If it was overheating, had the thermo & rad replaced but was still overheating, you must've been overheating too much and for too long and now you warped your shit, all along the symptom was oil & coolant mixing via the blown gasket, but wouldn't the shop doing the work notice oil & coolant mixed?
Shops fault.:tdown:
 
i'm having some issues with my coolant fluid. I put a new OEM radiator cap and the reservoir is overflowing..... No oil or foam.
I'm installing a new OEM thermostat soon. My only issue is that my 2010 FX35 is NOT overheating. But the reservoir is overflowing and spilling in my engine bay. Not sure what to do.
 
I replaced my Thermostat and Radiator cap. I also bled the coolant system on mine. I drove for over 2 hours today and the coolant level was just over the max level. My car has not overheated or had any overheat issues, but also no oil or foam or mixture.
I personally think there was too much coolant in the car, so what i did, was removed the excess off the reservoir and made sure the radiator was filled. So right now, in the cold my coolant level is just a little above the minimum level. I will drive it tomorrow for about 2 / 3 hours hours, and will make pit stops to see if i need to top off the radiator.

I'll update this tom.
 
I have this same issue and it started before installing a supercharger. I noticed that if I put the pedal to the floor several times, running through the first 2-3 gears and check the coolant after the engine has cooled down completely, there's more coolant in the expansion tank then there was prior. If I drive like a normal human being and don't floor it, after the engine has cooled down completely, the coolant is right at the line.
Seems this is likely a failed head gasket. I've read multiple people having this issue on completely stock VQ powered cars. Exhaust gas is being forced into a coolant jacket rather than oil and coolant mixing or a leak that's visible between the block and head. It's a very small leak.
A small leak in the system can prevent vacuum from the engine and coolant, vacuum which would normally draw coolant from the tank while it all contracts but I think if the results are different between these two very different driving styles, a head gasket is likely the problem.
If I drove the car, I'll check the expansion tank the morning after and if it's high, I'll use a turkey baster and manually transfer the coolant from the tank to the radiator, sometimes using the funnel to burp a few air bubbles. Keeps her going until I decide if I'm going to replace the head gaskets or build this thing.
 
onthemove said:
If I drove the car, I'll check the expansion tank the morning after and if it's high, I'll use a turkey baster and manually transfer the coolant from the tank to the radiator, sometimes using the funnel to burp a few air bubbles. Keeps her going until I decide if I'm going to replace the head gaskets or build this thing.
Click to expand...

I replaced the thermostat and the radiator cap and seems to help, i still go over the max line in the overflow tank, but not by alot. make sure are 100% sure its a head gasket because those things are expensive to replace.
 
Who_Ryder1 said:
I replaced the thermostat and the radiator cap and seems to help, i still go over the max line in the overflow tank, but not by alot. make sure are 100% sure its a head gasket because those things are expensive to replace.
Click to expand...

Yeah, expensive. I'd do it myself but it would still cost hundreds and take up my time.
I thought for sure I had a head gasket issue but I'm in doubt now. Couldn't help but notice a slight smell of coolant around the radiator. I replaced it years ago but someone smashed into my front end and the auto body shop replaced it.
I added this a couple weeks ago and so far, so good.
Best Radiator Stop Leak Tablets | Repair Radiator Leaks
"...In fact, this is the same product that’s been used right on the assembly line by OEM automakers around the world for 30+ years."
Supposedly, small leaks can allow air in or out without a detectable coolant leak.
 
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