Sr20det pressure in radiator hoses but not overheating

[dreek93sr20]

Wassup guys and gals if any...I have a red top sr that about 2 months ago put head gasket and arp head studs in and put everything back together and ran fine...then about a week ago i replaced the water in the coolant system with antifreeze and every since Ive had pressure build up in my radiator hoses..I replaced the thermostat the other day... there is no overheating or any driveability problems....Any help would greatly be accepted thanks....

PS... I tried to bleed all the air out....I have a matco coolant system funnel...could it be trapped air??

[fliprayzin240sx]

Did you bleed the air out of the system?

[dreek93sr20]

I did much as I could....did a radiator system pressure test a few mjns ago and its holding pressure....im thinking the thermostat is not opening up...or maybe blockage somewhere...

[fliprayzin240sx]

Pressure building up isnt always a bad thing. Jack the front up as high as you can, pop the rad cap off, start the car, crank your heater to full hot and massage the upper radiator hose. Keep the radiator topped off. Once you start feeling the upper hose get really hot, put the cap on and start feeling the lower hose. If the hose doesn't start getting hot after awhile, that means the thermostat isn't opening to let the coolant flow out of the radiator.

[dreek93sr20]

thanks for the input sir....will do that soon as I get off work...unlike most people I will post what fixes my problem and not just leave it blank

[dreek93sr20]

update...change thermostat(Nissan), even ran without a thermostat once, flushed system, changed water pump, and did a coolant system pressure test, still pressure build up....check out my vid here: Sr20det pressure in coolant system - YouTube (http://www.youtube.com/watch?v=1uWZpHOLaOc&feature=g-crec-u)

[cotbu]

pressure in the hoses is normal, as long as it's water and not air.
So check your temperature with an aftermarket gauge, consult or a thermometer.

When bleeding the system all you want is coolant. So if you fill the radiator and you cant fill it any more that's when you are actually bleeding the system. This is what I do: car off radiator filled, funnel attached and half a quart of coolant. massage the upper and lower radiator hoses. If there is any air being pushed out you should see the coolant go down in the funnel. Then I crack the bleeder valve slowly and allow any air too escape, I stop when water start to come out. Your system should be bleed, but your not done . start the car, let it idle, turn on heater and the coolant the is left should go down. but will quickly come back up, If so fill it quickly then cap it. Done

Now if you have other problems with loosing coolant or overheating it's not your bleeding procedure.

So where you are now in that video, let it cool down and check the level of coolant and squeeze the hoses and see if they are full of coolant or air.HINT the water level should rise. Air bubble should not be present at this stage.
You can do hydrocarbon test, that's why it's important to know the actual tempeture of your engine. you could be at 200f right now and the oem temp gauge won't move. it reads like this COLD ......Normal... Overheat.

[cbcm2435]

your coolant system is supposed to be pressurized, that is how it raises the boiling point of the coolant

[dreek93sr20]

but my hoses are so tight...when I turn off the engine you can here the pressure going into the overflow bottle...

[Kingtal0n]

If you've tried all the regular proceedures for bleeding the air from the system and verified the coolant is actually moving through the radiator, and you still think you have an overheating problem, I would install a high quality temperature sensor in the water outlet of the engine to verify that the temperature is in fact too hot.

[dreek93sr20]

guys it's not overheating at all... jus pressure build up in hoses

[Kingtal0n]

the radiator cap determines the maximum pressure allowable before it bleeds to the coolant overflow. most are around 1BAR (14~psi) so the upper radiator hose is going to get pretty stiff during normal operation.

[dreek93sr20]

its a 1.1 bar....but its pretty tight on both hoses

[fliprayzin240sx]

Did you try another radiator cap? Again make sure you bleed it properly by jacking up the front end as high as you can, turn on the engine, crank the heater heater to full heat and massage the upper radiator hose.

[fufanu180]

Im having the same issue right now. Just blew a coolant line underneath the intake manifold a week ago. Never overheats a bit. I'm going to try flushing the coolant system really well once more.

[dreek93sr20]

my problem was a blown head gasket... I changed it and problem gone away...for future references don't use cometic head gasket...I went with cosworth this time

[fufanu180]

That's what I'm thinking. It's just enough to get excess pressure into the coolant system but not enough to start overwhelm the coolant system and overheat the car.


CenTex240

[dreek93sr20]

Yea after about a week of the high pressure in the coolant system it finally leaked into cylinder 1... im using arp and was using a cometic....now I have cosworth

[fufanu180]

Did you deck it twice? Once when you originally took it off and then again when you put on the cosworth?


CenTex240

[dreek93sr20]

no I didn't deck it the first time jus put the head gasket on....

[fufanu180]

Isn't that crucial though?


CenTex240

[AsleepAltima]

you can also bleed it by pulling the upper heater hose and filling the radiator till the hose overflows. i run a 16psi cap with a cosworth hg and have no issues with overheating or over-pressurizing the hoses.

[jr_ss]

Did you deck it twice? Once when you originally took it off and then again when you put on the cosworth?


CenTex240

Isn't that crucial though?


CenTex240

Typically when swapping to a metal head gasket you want to ensure you have a completely flat surface. What will most likely happen since he didn't deck the oil pump cover/block is he'll notice possible seepage around the very front of cylinder #1 and the backside of the oil pump cover. However, he may not have any issues at all.

[fufanu180]

I'm just clearing the air. When putting on a metal hg you need to have both the block, head, and oil pickup decked? I always thought its just the head unless there were overheating issues.




CenTex240

[jr_ss]

I'm just clearing the air. When putting on a metal hg you need to have both the block, head, and oil pickup decked? I always thought its just the head unless there were overheating issues.




CenTex240

Usually, it's the oil pump cover that tends to stick up higher than the block, ever so slightly. This is where the issues can stem from on a metal headgasket. If you use a factory headgasket and ARP's you shouldn't have any problems and it'll hold 350whp reliably.

So, it would only be the oil pump cover/deck if need be. Having the head checked for trueness is always a good idea when changing out headgaskets, especially if you had some overheating issues.

[fufanu180]

Thanks for clearing that up. Well I'm at 19psi right now and I doubt I'm over 350 so just a good stock hg and arp studs should be worth considering?


CenTex240

[cotbu]

Thanks for clearing that up. Well I'm at 19psi right now and I doubt I'm over 350 so just a good stock hg and arp studs should be worth considering?


CenTex240
Boost doesn't blow head gaskets, Directly!;)
2013 people!

[fufanu180]

Just blew another coolant hose under the intake manifold. It has to be a boost leak. No problems when driving normal but when I drive it hard it blows a hose.


CenTex240

[dreek93sr20]

I think its a hg leak bro....I didnt wana do hg either but its not hard tp do a hg

[fliprayzin240sx]

If you keep blowing water lines under the manifold...REPLACE THEM ALL!!! If one blows, the rest brittle as fuck too.

Also, what pressure radiator cap are you using? Try a 1.1 bar cap if you're using something higher than that.

[fufanu180]

I know a hg isn't hard to do. I've done 4 so far. Not worried about it, just trying to motivate myself to do it.




CenTex240

[fufanu180]

If you keep blowing water lines under the manifold...REPLACE THEM ALL!!! If one blows, the rest brittle as fuck too.

Also, what pressure radiator cap are you using? Try a 1.1 bar cap if you're using something higher than that.

That's what I'm thinking. I'll replace them all and try a 1.1 instead of the 1.3 I have right now.


CenTex240