Jump to content
SAU Community

Coolant Pressure Issues

gL3nJaMiN88

By gL3nJaMiN88,
in Engines & Forced Induction

 Share

Recommended Posts

gL3nJaMiN88 Collaborator

gL3nJaMiN88

Posted
Posted

ok i've looked everywhere on this forum for some how to fix my issues but i cant find anything .

First things first my car runs hot , and i mean hot . I though it was just how hard i drive it but even driving short distance with no boost it gets around 95*c and when i boost it i can sometimes see 110*c.

OK the Waterpump + Thermostat 76*C Opening has been changed and also i put new coolant in with new hoses + Clamps .

Now i never noticed until one day someone pointed out that i have NO PRESSURE what so ever in my radiator hoses . Doesnt matter if its a 20 min drive or a 2 hour drive i have sweet shit all pressure in my hose .

I mean i can take radiator cap off whenever i feel like it with nothing over flowing . THe coolant is right at top of radiator just like it should be + my overflow bottle it full right to max!.

I thought it could be my radiator cap , but its a brand new NISMO item that i purchased like 4 months prior..

i've tried finding a simple post how to bleed system but no one has a post on it ? only site i found was some other stupid sight that said to jack car up and take cap off while the heater is on and it will bleed? but yeh didnt do anything .. Tried that little bolt on manifold but i can take screw out and nothing happens .

Now before you say its the waterpump , it cant be .. when i rev the car you can see the coolant moving around the radiator very fast.

I've rang every radiator place and they said they have no idea what it is? has anyone had a similar issue ?

what could it be ? Im not loosing any coolant either

Link to comment
https://www.sau.com.au/forums/topic/297645-coolant-pressure-issues/
Share on other sites
simpletool Mentor

simpletool

Posted
Posted

Radiator cap or radiator sealing issues (do you have after-market radiator?) Does the cap SEAL against the lip inside the radiator? Check for indent in the inner radiator seal - the inner one that is sprung. (And yes, I read every word of your post).

Related issues - when hot does the overflow bottle fill-up more? If not there must be a large amount of air in your system.

Take off the vertical screw that is between the PCV valve and plenum (it is at a high point). Take off the radiator cap - turn on your engine. Pour water into radiator - etc etc. Rev engine a little with throttle - bubble should come out either radiator or screw (out screw back in a few turns and repeat to get smaller bubbles out).

This process is better if car is SLIGHTLY pointing uphill.

STATUS Grand Master

STATUS

Posted
Posted (edited)

it can take 15mins to bleed up to the bleeder bolt on some cars, but honestly if you driven it a few times and topped it up it is really the same thing.

Another issue could be the new thermostat, we only use genuine nissan ones as we found about 7 in 10 tridon or similar aftermarket one did not open properly in the rbs' and sr's.

get your rad checked too.

We had a similar issue with a customer who see regular track days he had brand new china brand radiator (2 months old) it kept over heating so i changed everything around it only to find the radiator was useless, put a new one in (ASI) and car was fine

Edited by URAS
payback21 Community Regular

payback21

Posted
Posted

Thats true, it does take a little bit of a while to bleed from the bleeder on the manifold.

It pays to have the heater on when bleeding it so it can get the air out of the heater system if there is any. Water should trickle out of the bleeder when its got the air out.

It does sound like a air lock. You do want to watch that you dont over heat it and warp the head. Thats the least thing you want to happen.

Moodles2 Grand Master

Moodles2

Posted
Posted

Not a fan of Nismo or aftermarket rad caps that bring the pressure up to 1.3kg/cm2, just puts more strain on the hoses, increasing risk of them popping them off for afew extra degrees before the coolant boils.

shyr33 Community Regular

shyr33

Posted
Posted

Hey mate so did you change to a new waterpump? What brand was it? Now I am no expert but isnt it the water pump which will create the pressure in the system? And if you have a properly sealed system then there should pressure.

So either the pump is not creating enough pressure or the pressure is leaking outwards somewhere and as mentioned one of the main reasons for a car running hot is air in the system or you have a very fouled radiator. That happened to a friend of mine. Car was overheating, took of the radiator and gave it to a radiator shop and got it cleaned. They said it had alot of shit in it, put it back on the car and ran ok.

funki_munki Collaborator

funki_munki

Posted
Posted

i recently bought a new radiator for my 32 got a koyo rad direct replacement for 270 cost price from my mums work, the guy also cleaned and straightened out my old one and it was 70% blocked. as moodles2 said a .9bar rad cap will suffice,i got a cpc one and the difference between the old and new was heaps the spring on the old was soft the new one is firm.

as for bleeding the system,i used a coke bottle that was chopped and held that in the radiator and filled that up and waited for the bubbles to pop up,after that i just filled the resevoir up and i keep a eye on it for the first couple of days just to make sure.

Beer Baron Grand Master

Beer Baron

Posted
Posted
Hey mate so did you change to a new waterpump? What brand was it? Now I am no expert but isnt it the water pump which will create the pressure in the system? And if you have a properly sealed system then there should pressure.

So either the pump is not creating enough pressure or the pressure is leaking outwards somewhere and as mentioned one of the main reasons for a car running hot is air in the system or you have a very fouled radiator. That happened to a friend of mine. Car was overheating, took of the radiator and gave it to a radiator shop and got it cleaned. They said it had alot of shit in it, put it back on the car and ran ok.

no it's heat which creates pressure in the system. the hotter the coolant/water gets the more it expands. water kept under pressure raises it's boiling point. once the heat gets so much that the pressure exceeds the spring pressure of the cap then the cap releases pressure (water) which then boils in the overflow tank immediately as it's already over 100C and no longer under pressure any more. all the pump does is push water around, it's the heat that creates the pressure and it's for that reason (to enable the coolant to reach higher temps before boiling).

Duncan Grand Master

Duncan

Posted
Posted

yep that's right, and the pressure of the cap dictates the maximum temp the system will get to. Once it reaches the cap's pressure it will let water out and the coolant won't get any warmer. 1.2 bar is about 120o and 1.3 bar about 132o. Assuming something else like a heater hose doesn't crack under that pressure first of course.

blind_elk Grand Master

blind_elk

Posted
Posted

Pumps create pressure. Pressure (differences in pressure) causes fluids to move.

The expansion of water when heated, even in an enclosed space, is insufficient to create the kinds of pressure you see inside a cooling system. And there will always be some air inside the cooling system, which will absorb the pressure increases far more readily than water will.

Back to the OP - I think you will find that the water pump impellers are cactus, and the water is not circulating properly.

gL3nJaMiN88 Collaborator

gL3nJaMiN88

Posted
  • Author
Posted

hey guys i have fixed my problem all together .. I purchased a 45mm aluminium radiator from autobarn . The brand is autotecnica and it is very well made .. And the price was pretty good aswell only 200 for me as i work there .. I flushed the system until the water that came out was as clean as it went in .. I only used demineralised water aswell .. Then i put new radiator in keeping original shroud , and it only took like 10 mins .. Put new nulon RED coolant in with water .. Checked my coolants Mv to make sure i had no electrolises .. Which i didn't and car runs amazing now .. Builds up pressure nice and i don't see a temperature over 85*c on hot day giving it some and on cool nights just cruising around i see around 78-80* at most ..

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      All I hear is ROADTRIP!
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...