another bubbleing coolant reservoir.

[soryu]

so the reservoir is bubbling after i turn off the car.
the temp gauge has gone up after idleing two times in a week.
i've replaced the water pump,thermostat,fanclutch,rad cap.
my bottom rad hose is always cold, well not as hot as the top hose.
the reservoir doesn't overflow it gets full then around an hour later it's back to normal between max and low. i have flushed the rad out.
a/c works fan works. rad has been burped.
anyone know what could be the problem?
replacing the radiator is the only thing i can think of.
no white smoke,no milk in oil.

[Mitsubayati]

How did you "burp" it? You should be jacking up your front end as high as you can and have the car running with the cap off and a funnel full of fluid on it to properly "burp" the system.

I have an inclined driveway, so I put my car on that and then jacked the front end up.

[hOngsterr]

i have the same problem lol, but i have a new water pump, cap, radiator, and thermostat.

my coolant bubbles slowly, but whatever lol

[RyanS13]

Bottom radiator always being cold sounds like the thermostat isn't opening.
Where did you buy your thermostat from? Ive had brand new thermostats not work on me multiple times. Get an OEM nissan one, they're the only ones that seem to work.


Then burp it again for like 25 minutes. Jack the front end up as high as you can and run it like that with the radiator cap off, with the heater on full blast.

[soryu]

i went out for a drive car didn't overheat.
got home idled for a minute or two temp gauge started going up i turned off the car and started hearing bubbleing. i checked the reservoir it was ok the bubbleing was coming from the top hose i lifted it up a little and it stopped.the bottom hose was cold.
i tested the thermostat and it works from autozone.
i'll try burping it again today.

[soryu]

I'm about to burp it again.
I checked the hoses and there both warm?

[wangan_cruiser]

thats good, it indicates the coolant is recirculating and thermostat is opening

[N2HIFI]

Blown head gasket, it's putting air into your cooling system, Henie you have blow by bad pressurizing your cooling system

[MidwestMyriad]

Just to touch on the burping issue.

If you own a 240 you need this.


Best $20 ever

[william's']

listen to N2HIFI, and the way to confirm that is; dry/wet compression, cylinder leak down tests.

[william's']

and next time do a proper daignoses so your not spending cash on stuff you dont need.

[estanislao]

He said there is no chocolate milk or white smoke and im pretty sure he would of noticed oil in his coolant since he has been messing with it plus I'm pretty sure if the was conpression on his coolant he would of noticed it while burping it I dont think its a head gasket.I'm having the same problem btw but because of it being recently rebuilt good luck hope it solved your problem

[soryu]

i tested the rad pressure.
(needle didn't move 30min)
and cyl compression.
(all 4 150)
also pics of the temp spike.

[Walperstyle]

run with no thermostat, check again.

If problem is gone without thermostat, then buy a new thermostat.
(no really, I have had the same issue, and went to get a thermostat, figured it would be fine, but right from the parts store it failed... it happens, you may have got a bad one from the factory)

[soryu]

i checked the thermostat and it works.
i flushed the radiator dropped in some new coolant and found this in the reservoir looks like dust. it didn't smear when i rubbed it.

[MedHat240sx]

I have the exact same problem Super annoying temp will spike after 30 min of driving for max 40 seconds drop instantly. dont know what it is brand new thermostat flushed and properly burped the system no change.

[soryu]

well drove my car around today. no bubbleing and car didn't overheat.no temp spike either.coolant in reservoir stayed the same i did add some coolant in the morning though,
like half a cup.
top hose hot,bottom hose warm.

[lbourgoin4]

it indicates the coolant is recirculating and thermostat is opening

[Walperstyle]

one hose is going to be hotter then the other, that is how it works.

Originally Posted by lbourgoin4

it indicates the coolant is recirculating and thermostat is opening

Not necessarily, some thermostats have a small bypass for when they get hot to save an engine

Originally Posted by soryu

i checked the thermostat and it works.

take it out and throw it in a pot of hot water next time, also check if its got a bypass on it

i flushed the radiator dropped in some new coolant and found this in the reservoir looks like dust. it didn't smear when i rubbed it.

reservoir = overflow? I would not worry about dust or a little dirt in your coolant. If its sludge, then you have a really ghetto car.

If the problem continues, , pop the rad cap and bleeder, rev the shit out of it, and consider running with no thermostat just to see what happens.