Jump to content
SAU Community

Is This Sort Of Overheat?

jbjb

By jbjb,
in V Series (V35, V36, V37 & Infiniti)

 Share

Recommended Posts

jbjb Explorer

jbjb

Posted
  • Author
Posted

I wrote a proper bleed procedure somewhere on G35, just search my name.

Also get a radiator cap with temp control gauge on it, you can go check yourself.

Thanks, Nate. Radiator cap with thermo gauge like this with 16psi?

$(KGrHqIOKiYE1dZ+bfQzBNdw!H78tg~~_12.JPG

  • Replies 40
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

jbjb Explorer

jbjb

Posted
  • Author
Posted

I am leaving mine as is as I am pretty certain its normal. I think I saw a similar thread on here that said the same thing. I had mine serviced and no problems were found. Also my needle is just below the middle, yours is above middle.

Ok, at least you are innocent now :no:

jbjb Explorer

jbjb

Posted
  • Author
Posted (edited)

except that water temp at the radiator isnt water temp in the engine which is where you really need it

Oh..right..nearly de-focus now. Should check air first. Step by step. Will feedback to you guys all then.

Found this link has more detail of how to bleed your coolling system though it is for BMW

I also found Nate's recommended linkI also found Nate's recommended link (http://infinitihelp.com/diy/gcoupe/projects/infiniti_g35_coolant_service_procedure.htm)

which is really helpful to locate the air release screw, thanks!

Edited by jbjb
sonicii Veteran

sonicii

Posted
Posted

except that water temp at the radiator isnt water temp in the engine which is where you really need it

True.. and if you are low on water, this gauge will probably read low too.

sonicii Veteran

sonicii

Posted
Posted

Yes, but when you lose coolant, the first place you will get air is in the top of the radiator as most cars are designed for this to the be the highest point. If the boiling coolant doesn't contact the radiator cap, the gauge in the cap will read low. Just like the normal coolant temp sensor will read low when you lose enough coolant for it to be surrounded with air instead of cooant.

zei20l Grand Master

zei20l

Posted
Posted

no, it will read high if there is no water. water wont boil under pressure in a sealed environment. like a cooling system in a car!

put some air in there and the water WILL boil and show a higher temp due to the steam being hotter than the water.........

sonicii Veteran

sonicii

Posted
Posted

Um.. nope.. water under pressure boils at a higher temperature, the pressure doesn't keep the water cooler, it increses it's boiling temperature, so you could have steam at 101deg C in an open system, and it will be cooler than water at 110 deg C in a pressurised system.

Add to that.. steam is not necessilary hotter than the water it just boiled off, unless there is an additional energy source to heat the steam directly.

Also, steam doesn't conduct heat anywhere near as well as water, so even if there is steam at 101degC surrounding the temp gauge, it is still likely to read below that temp. if you have ever had a cooling system leak on a car, you will find the temp gauge drops once the coolant falls below the temp sensor, even though the engine is overheating and boiling the remaining coolant.

Daleo Grand Master

Daleo

Posted
Posted (edited)

Um.. nope.. water under pressure boils at a higher temperature, the pressure doesn't keep the water cooler, it increses it's boiling temperature, so you could have steam at 101deg C in an open system, and it will be cooler than water at 110 deg C in a pressurised system.

Add to that.. steam is not necessilary hotter than the water it just boiled off, unless there is an additional energy source to heat the steam directly.

Also, steam doesn't conduct heat anywhere near as well as water, so even if there is steam at 101degC surrounding the temp gauge, it is still likely to read below that temp. if you have ever had a cooling system leak on a car, you will find the temp gauge drops once the coolant falls below the temp sensor, even though the engine is overheating and boiling the remaining coolant.

What you said about the water temp reading lower once there's no water in the system is correct; it's a water temp gauge, not an air temp gauge.

This is semantics.

The thing is; the object of pressurising the cooling system is to avoid boiling the water. But there cannot be any air trapped in the system for this to occur.

Running your car at 100deg with a cooling system full of boiling water is an undesirable condition, as the expanding air (steam) forces water out of the cooling system when it boils.

Water turning to steam can expand to 1000 times its original volume.

Eventually the expanding steam will force virtually all of the water out of the system. The water pump cannot pump air. Once there is no water in the system you have no ability to transfer heat out of the engine in any measurably useful amount.

This is BAD.

Having water at 110deg with no expanding air bubbles (also forcing the water pump to cavitate) ensures all the water stays in the cooling system. This is where you want it. In addition, the coolant in the cooling system pushes the boiling point of the pressurised water up to around 120 deg.

Pressurising the system and adding coolant are just ways of providing extra headroom to the system. It works.thumbsup.gif

Edited by Daleo
sonicii Veteran

sonicii

Posted
Posted

Nope. A coolant temp gauge goes down.. if you have a head temp sensor, that will go up as the engine overheats.

I probably should qualify that by adding - if the engine is running at normal temperature, and the coolant gauge is in the normal position - then you lose all the coolant while driving (eg blown lower radiator hose), the coolant gauge will drop,not go up. Have had this happen once to myself, and has been confirmed by others who have had the same occur.

Just in case someone though I meant starting a cold engine without coolant.

  • 3 weeks later...
jbjb Explorer

jbjb

Posted
  • Author
Posted (edited)

Your thermo fan should come on even when the a/c is off, once the car gets hot enough.

I would be checking for air in your system (which I bet is the cause). Or get a mechanic to install a water temp probe and actually check your water temp to see if your stock gauge is lying/broken.

My mechanic probed in the radiator and it showed 93degree, but when fan started working, it came back to 86......my mech recommended to change the thermostat. Will see how it goes tomorrow. If not, we may check toward blockage.

Edited by jbjb
sonicii Veteran

sonicii

Posted
Posted

My mechanic probed in the radiator and it showed 93degree, but when fan started working, it came back to 86......my mech recommended to change the thermostat. Will see how it goes tomorrow. If not, we may check toward blockage.

Nothing wrong with those temperatures, was the gauge sitting in the normal position when the probe was reading between 86-93? (normal for you which is above half?)

Chris Rogers Grand Master

Chris Rogers

Posted
Posted

go see someone about it - carmen is probably the best one to do it. I have a scan tool but given its being a pain in the arse at the moment I can't plug into the car anyway.

go see someone about it and start there. most of the cars I have been privy to seem to dispaly what you have shown.

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
      "Cheap" bolt on turbo on RB25DET NEO

      By MBS206 · Posted

      HyperGear. Just get a high flow of the stocker. Good, reliable, and should bolt on. Yes it will want things like a retune once done, so you need to factor this in to your spend too.
    • Kapr
      "Cheap" bolt on turbo on RB25DET NEO

      By Kapr · Posted

      Hi. Iam looking for some "cheaper" bolt on turbo on RB25DET NEO. I do not want "big" power just better reliability than the stock turbo which is "fot now" good but is old and i do not think it has "easy" life. One the Skyline here running some "temu" china Turbo but i dont trust those... Thanks!  
    • Piggaz
      R33 GTR OEM parts + random parts and oils

      By Piggaz · Posted

      Hi guys, Making some space/cleaning up. A whole heap of random OEM R33 GTR parts and other random bits and bobs. I will update this thread as I go. Parts are located in Moorebank NSW 2170. Pickup preferred but will post at buyers expense. Prices are negotiable. If they don’t sell it will go in the bin. Item 1: BOV return pipe. $40 Item 2: RB26 cam gears. $20 Item 3: R33 GTR torque split, oil temp, boost centre gauge. $100 Item 4: RB26 fuel rail x 2. $20 each Item 5: RB26 Recirc valves. $50 Item 6: OEM upper front arms. $20 Item 7: Royal Purple Max Gear 75w-140 1 quart/946 ml x 5. $50 each or 5 for $200. Item 8: OS Giken 80w-250 diff oil 1 litre. $25 Item 9 Eibach springs. ers-11-140-60-0140. $100 https://www.streetfx.com.au/eib140-60-0060-eibach-ers-140mm-length-x-60mm-id-coil-over-spring?_ga_campaignid=22235933977&_ga_adgroupid=180146800292&_ga_keyword=&_ga_device=m&_ga_target=pla-295238231169&_ga_locint=&_ga_locphy=9071723&_ga_matchtype=&_ga_network=g&_ga_device=m&_ga_placement=&_gcl_id=CjwKCAjwlt7GBhAvEiwAKal0cvkVE_hstv24cDiaICsIk1oznH9zAoJf3By6vR3Tpe7jmByqM6JFHBoCZYAQAvD_BwE&gad_source=1&gad_campaignid=22235933977&gbraid=0AAAAADPiTbo1xAuvnjIWWYnezivf-BUSY&gclid=CjwKCAjwlt7GBhAvEiwAKal0cvkVE_hstv24cDiaICsIk1oznH9zAoJf3By6vR3Tpe7jmByqM6JFHBoCZYAQAvD_BwE    
    • MBS206
      remote oil cooler hose size, 8,10 or an12?

      By MBS206 · Posted

      That's kind of what I was getting at saying you'd be here soon regarding length etc being able to add additional restriction.  My assumption (possible donkeys of you and mption) is that the length of hose to an oil cooler, and back, isn't going to be that huge of a loss. Typically you're talking about 1.5m of total length. And so far everyone in our world hasn't had issues with oil not being able to get to a cooler and back, it's more been, how the heck do we get the oil out of the head and back down to the bottom? I'd nearly hazard a guess the biggest issue people have with oil cooling and oil supply, is being able to get the heat out at the cooler itself (not enough air flow, too small of a cooler etc) Also, when people mount them wrong and make really awesome air traps so they've dramatically diminished the cooling capacity.
    • GTSBoy
      remote oil cooler hose size, 8,10 or an12?

      By GTSBoy · Posted

      I will rebutt this and the preceding point from Dose....but without doing any calcs to demonstrate anything and without knowing that I am right or wrong. But... The flow capacity of a fluid transfer system is not limited by the smallest orifice or section of conduit in that system, unless it is drastically smaller than the rest of the system. OK, I use the word drastically perhaps with too much emphasis, but let's drill down on what I really mean. The flow capacity of the system is the result of the sum of the restrictions of the entire system. So, to make an extreme example, if you have a network with 3" pipe everywhere (and let's say a total length of only a few metres) and that 12mm ID restriction of the oil filter connection being the obvious restriction, then for any given amount of pressure available, the vast majority of all the pressure drop in the system is going to occur in the 12mm restriction. But.... increase the length of the 3" pipeline to, say 1000m, and suddenly the pipe pressure loss will likely add up to either be in the same order of magnitude, possibly even exceeding that of the 12mm restriction. Now the 12mm restriction starts to matter less. Translate this to the actual engine, actual oil cooler hose sizing, etc etc, and perhaps: The pressure loss caused by flowing through the narrow section (being the 12mm oil filter port, and perhaps any internal engine oil flow pathways associated with it) is a certain number. The pressure loss through, say, -12 hoses out to the cooler and back is negligible, but The pressure loss through -10 hoses out to the cooler, at the exact same length as the above, starts to become a decent fraction of the loss through the 12mm stuff at the filter port. Maybe even it starts to exceed it. I could actually do these calcs if I knew 1) how much oil was actually flowing in the line, 2) gave enough of a f**k to do things that I hate doing for work, voluntarily for a hypothetical discussion. Anyway - I reiterate. It's not the narrowest port that necessarily determines how much it can all flow. It is the sum. A long enough length of seemingly fat enough pipe can still cause more loss than a semmingly dominant small bore restriction.
×
×
  • Create New...