Complex Overheating Issue

[zebra]

Ive seen 50/50 mixes of Glycol/Anti freeze anti boil, boil too.

Anti-Boil or coolant what ever you want to call it usually boils at 115-120deg C

Water under pressue will boil at say 105deg C

Trick is to not let it get that hot, which is what this thread is about.

Which just made me think - Nisskid - are you using an overflow bottle? might not stop the boiling but might help the bursting hoses.

The other thing that hasnt been mentioned is water pump cavitation. What sort of pump is it? a generic Rb30 pump or genuine Nissan? Moght be worth looking at getting an N1 pump if the car is seeing sustained high rpm, or even possibly an electric water pump.

[Simon-S14]

Ive seen 50/50 mixes of Glycol/Anti freeze anti boil, boil too.

Anti-Boil or coolant what ever you want to call it usually boils at 115-120deg C

Water under pressue will boil at say 105deg C

Trick is to not let it get that hot, which is what this thread is about.

Which just made me think - Nisskid - are you using an overflow bottle? might not stop the boiling but might help the bursting hoses.

The other thing that hasnt been mentioned is water pump cavitation. What sort of pump is it? a generic Rb30 pump or genuine Nissan? Moght be worth looking at getting an N1 pump if the car is seeing sustained high rpm, or even possibly an electric water pump.

if there is a fault in the cooling system it wont matter if its water, coolant or concentrate in there.. it will still over heat. water will have a higher boiling point the higher the pressure is in the system. having coolant in there will raise that by a few degrees if that.

as for water pump.. if you read further up he said he's been tracking it for ages and this has only recently become a problem. besides theres plenty of other RB20's that get tracked and thrashed at high RPM with no issue.. the pump is not the fault here.

[O2 Autosports]

sounds like a head gasket leak. seen this problem a few times lately. drill some holes in the thermostat or remove it completely, if it fixes the problem it means its getting an air lock at the thermostat and not allowing it to heat up and open. time to start doing some maintenance stuey

[Simon-S14]

would u drift with no thermostat tho nathan?

[O2 Autosports]

to diagnose a problem- definitely. or if your worried just drill a few holes in it.

[Simon-S14]

yeah still need some restriction. my 25 hated life with no thermostat

[nisskid]

cheers for the help guys, with the help of a blow torch ive unseized the bleed bolt, so ive now retapped it, and put a new bolt in with a 12mm head, so it can be bled properly.

the head is coming off tomorrow anyway.

[nisskid]

yeah still need some restriction. my 25 hated life with no thermostat

yeh, like i said, gonna gut the thermostat so there's still some restriction, but i can be sure it's definitely open. i know the thermostat is ok, but if there's something else like a huge air lock that's f**king with it, then this might help.

[nisskid]

Ive seen 50/50 mixes of Glycol/Anti freeze anti boil, boil too.

Anti-Boil or coolant what ever you want to call it usually boils at 115-120deg C

Water under pressue will boil at say 105deg C

Trick is to not let it get that hot, which is what this thread is about.

Which just made me think - Nisskid - are you using an overflow bottle? might not stop the boiling but might help the bursting hoses.

The other thing that hasnt been mentioned is water pump cavitation. What sort of pump is it? a generic Rb30 pump or genuine Nissan? Moght be worth looking at getting an N1 pump if the car is seeing sustained high rpm, or even possibly an electric water pump.

shit, didnt see all these extra replies.

yep , still running standard overflow bottle. im using a GMB as far as i can tell as it's a 6-blade pump, i know it's not the main problem as i ran it for years with no issue, but im going to either a genuine nissan or endurotec which are both small 8 blades to reduce cavitation, as being an RB20 and how i drive RB20's, it never really goes below redline haha

[nisskid]

sounds like a head gasket leak. seen this problem a few times lately. drill some holes in the thermostat or remove it completely, if it fixes the problem it means its getting an air lock at the thermostat and not allowing it to heat up and open. time to start doing some maintenance stuey

lol im paying for years of NO maintenance now. although i get the feeling it's something basic, which is the worst considering how much of the engine im pulling apart to find it. but at least she will be fresh by the end of it lol

[STATUS]

reco radiators are a crock ive had about 5 done over the years and its never fixed the issue... bin it or recore it. We have also seen a few of the jjr ally rads weld them selves together internally from stray current.

if its re-cored the water pump must be screwed.

pull the thermostat and check flow, if it has no flow at the rad cap then generally its the rad, but you can bypass the rad with pie to check if the water pump is woking (rare to fail but ive seen a few that ran on water for too long and the blades rusted off )

other thing is those autobarn and repco tridon thermostats are junk and often fail out of the box.

[D_Stirls]

say what you like but... I have personally seen water in heat exchanging systems run hot and boil. Coolant doesn't do that. Lol whatever gets you off tho. I guess we are all qualified mechanics here aye?!

Coolant reduces the waters ability to carry heat, the coolant might not get as hot but the surfaces that you are trying to cool(the head and bores) are hotter due to the reduction the efficiency of the thermal transfer. So you are correct the coolant won't boil but it isn't really achieving what you want either.

In day to day applications it does the job but for performance applications i don't like it.

My vote is for water with a water wetter that has a corrosion inhibitor and an higher pressure cap incase the temps do get high and you need to stop the water boiling; but if your cooling system is sorted you should need to worry about temps getting high.

Edited June 7, 2011 by D_Stirls

[nisskid]

reco radiators are a crock ive had about 5 done over the years and its never fixed the issue... bin it or recore it. We have also seen a few of the jjr ally rads weld them selves together internally from stray current.

if its re-cored the water pump must be screwed.

pull the thermostat and check flow, if it has no flow at the rad cap then generally its the rad, but you can bypass the rad with pie to check if the water pump is woking (rare to fail but ive seen a few that ran on water for too long and the blades rusted off )

other thing is those autobarn and repco tridon thermostats are junk and often fail out of the box.

i've both tested the flow myself, as well as had it checked professionally, there is no restriction from the core, at least nothing significant.

[STATUS]

i've both tested the flow myself, as well as had it checked professionally, there is no restriction from the core, at least nothing significant.

is top of rad different temp to bottom?

[nisskid]

from what the gauge is telling me yes.

[STATUS]

then you have no flow.

[battery]

i've both tested the flow myself, as well as had it checked professionally, there is no restriction from the core, at least nothing significant.

When i had a radiator that was %80 blocked i could stick a hose in the top and water would flow very freely out the bottom so i thought it was fine but it still overheated, ended up taking it to a shop they refurbed it and that fixed my overheating issues...

But if you had it flow tested "professionally" you would think it was good!

[nisskid]

then you have no flow.

lol, thanks mate.

[nisskid]

When i had a radiator that was %80 blocked i could stick a hose in the top and water would flow very freely out the bottom so i thought it was fine but it still overheated, ended up taking it to a shop they refurbed it and that fixed my overheating issues...

But if you had it flow tested "professionally" you would think it was good!

yeh mate, they also took the tanks off and checked the core's with their prodding tool (nfi what they call it) and manually made sure there was no junk in any of the core still.

[GTScotT]

I had all of the above issues plus more on an SR.. I ended up thinking it was a cracked head that only became evident at certain temperatures, bleeding combustion gases into the coolant.

What it turned out to be... Was... A low quality intercooler blocking airflow to the engine bay...

No shit.