Whilst you are lowering the boiling point by a few degrees, you are also lowering running temps few degrees as well.

30/70 = 105 degrees boiling point
50/50 = 107 degrees boiling point

This is unpressurised, so the 16psi in the sytem will raise this a few more degrees in both instances by 5 degress (IIRC). I don't know about the diesel, but that is redline on the petrol. Something else is wrong if you are hitting the redline on the temp (in any vehicle) in my experience.

When I was running 50/50, my system would often go just past 100 degrees.

Running 30/70, the first thing I noticed was that the system was running only a couple of degrees cooler, but the big thing I noticed was it spent less time at the 100 degree point. I didn't expect this last point, but it stands to reason that if the system has more water, it will be more efficient in sheding the heat.

Either mix is good in my opinion. I just think (at the moment anyway) that 30/70 in a healthy system seems to work well in my experience.

Righto ... lets see if a little info really is a dangerous thing ... :) ...
Rodge & I both share the view that sometimes too much, is .... but his opinion was that it should be available to be read ....

Soooo ......

At the bottom of this post is a link tooooooo ....... DONT LOOK AT THE BLOODY THING YET ...... http://www.freesmileys.org/smileys/smiley-angry009.gif

At the bottom of this post is a link to one of the more easy to follow graph setups on Eth-Gly/Water properties.

Not all of it, makes a lot of sense to me but the numbers and details match other sites/publications Ive compared it against ... and I would be particularly interested in finding out whether the viscosity of 50/50 ... in any way makes up for its other deficiencies as a hot climate "coolant" in an inefficient cooling system.

Caution needs to be exercised when looking at the info ..... the same caution that should be applied when reading our opinions on forums and other websites. ;)

Why ???? ... heres an example.

Theres a table in the link, displaying the boiling points of different percentage mixes ..... and when you look at the 100/0 eth-gly/water - boiling point .... its about 200*c

YAHOO ... My XJ will never boil over again http://www.freesmileys.org/smileys/smiley-happy093.gif But when you look at the XJ FSM ... my think points in the lighter colour ... and cross reference the other tables of characteristics ......

ETHYLENE-GLYCOL MIXTURES
The required ethylene-glycol (antifreeze) and water mixture depends upon the climate and vehicle operating conditions. The recommended mixture of 50/50 ethylene-glycol and water will provide protection against freezing to -37 deg. C (-35 deg. F) ... depends on the climate huh :roll:... and nothing about high temp protection ????

The antifreeze concentration must always be a minimum of 44 percent, year-round in all climates. If percentage is lower than 44 percent, engine parts may be eroded by cavitation, and cooling system components may be severely damaged by corrosion ... so some consideration MAY be nescessary regarding the 0.2 viscosity difference shown in the link ... or is it because chrysler arent differentiating between the eth-gly AND the added anti-corrosive products ???

Maximum protection against freezing is provided with a 68 percent antifreeze concentration, which prevents freezing down to -67.7 deg. C (-90 deg. F). A higher percentage will freeze at a warmer temperature.
Also, a higher percentage of antifreeze can cause the engine to overheat because the specific heat of antifreeze is lower than that of water... so more is not better.

COOLANT SELECTION-ADDITIVES
Coolant should be maintained at the specified level with a mixture of ethylene glycol-based antifreeze and low mineral content water. Only use an antifreeze containing ALUGARD 340-2 y. coz eth-gly isnt an inhibitor as such, and needs the additives, all the chemists test for as per the samples of materials provided by the carmakers over the years.

100 Percent Ethylene-Glycol—Should Not Be Used in Chrysler Vehicles
Use of 100 percent ethylene-glycol will cause formation of additive deposits in the system, as the corrosion inhibitive additives in ethylene-glycol require the presence of water to dissolve ... and its not the corrosion inhibitive additives in eth-gly ... but the corrosion inhibitive additives ADDED TO eth-gly.

Additionally .... when the "specific heat capacity" is examined using a table in the link ...
100% eth-gly only needs a heat amount change/influence of .66 at the XJs "normal" 93*c/200*f running temp to cause a 1* fluid temp rise .... whereas 50/50 needs .865 ... and 30/70 needs .936

So what looks good initially ...pans out to be the wrong stuff to use ... Still ... that 200*c 100/0 boiling temp might justify the "anti-boil" advertising on the bottle ;) :roll:



Another point made in the link is the increasing of flow rates to make up for the deficiencies in eth-gly mixes. http://www.emotihost.com/peeing/1.gif

Noooo .... bling bunnies :p ... this doesnt mean race out and buy some higher flow waterpump ... coz theres not a lot of point speeding up the flow into a heat exchanger (radiator) that wasn't efficient enough .... at the slower flow speeds ... Besides - the yanks have been using eth-gly for so long the factory waterpump should be right :wink:

...... and then theres cavitation issues, hot spots in the galleries ( the thing murray referred to earlier ) and no doubt a lot more. If you want to use such a device ... go for it - its your vehicle ... but at least know what it will or wont do for you ..... same as all the other wonder cures out there .... ;)

Something that is missing in the link was the lower heat shedding ability of eth-gly .... but the FSM states thats a fact ... so lets give chrysler the benefit of the doubt ... ;)

Lots of the sort of info in the link .... and even some of the FSM info is also really only pertinent to a vehicle sitting on a dyno machine/controlled environment ... or coldroom chillers .... as the constant variation in driving conditions, engine loads, wind chill, ambient temps, reflected driving surface heat, your right foot, yada yada, make driving .... a very fluid environment ... if you'll excuse the pun. :)

So be careful with it .... ;)

BTW ... This is not about 30/70 over 50/50 just coz stoopid carves said so .... its about awareness of a product .... and what YOU do with it.

Im of the opinion that 30/70 is better and use what I use .... but even a quick trip over to the NAXJA forum will find the cooling fellas suggesting 50/50 for winter and 30/70 for summer due to their http://www.millan.net/minimations/smileys/snowing.gif http://www.millan.net/minimations/sm...athermanf1.gif weather extremes.

Mix ratio choice is all YOURS ..... should you choose to weigh up the pros & cons. ;)

phewwww .... damn post is nearly bigger than the link page .... :mrgreen:

OK .... now yaz can clickey clickey ..... http://www.engineeringtoolbox.com/et...col-d_146.html

Great thread guys! :mrgreen:


Personally... I prefer the Tectaloy 90Plus premix/complete fill combined with a 1Lt concentrate "booster" (to the overall cooling system) taking the ratio to between 33~50% EG/W... I do this because my water source is mineralised (alternatively I could collect rain water) ;)

grocery stores dont sell distilled water in Taz?

Carves... someone is showing their age!!!!!

Yeah they do I guess... but when I can pick up a bottle of Tectaloy premix on sale for less why would anyone want to?


BTW Rodge I'm in Victoria :p

just had a look at the castol web site and they recomend the same coolant as a vy comodore i started a thread about this i while ago and it got shot down but here we are again talking about coolants and mixes

Question
 

Ok, I am ready to replace the coolant (Tap water :oops:) In my XJ. I have a bottle of NULON Ultra Cool concentrate, but I have come accross a cheap readymix that is eth/gly free. It has corrosion inhibitors, lubricants and rubber conditioners in it.
What are your thoughts?
So far, (touch wood) my cooling system has been performing well. (It bloody well should:mad:)

cheers

Wouldn't use anything but demineralised water myself. If you cannot get demineralised water at an auto store or a supermarket, use a premix coolant with eth/gly (and find another auto store :)). If your system is performing so well, why compromise it? why not treat it to the good stuff? I know some brands sate you can use tap water, but why would you want to for the sake of $1 a litre?

Not sure what the "eth/gly free" coolant is you are talking about, but I wouldn't use anything but eth/gly in my XJ. No other reason than that is what the service manual calls for and I do not know what the effect of running a non eth/gly coolant would be on the system, somone else might be able to expand on this.

If you don't get all the old eth/gly coolant out in it entirety I would be worried about the chemical reactions I have heard so much about (some scream "truth" and others scream "myth", but I don't have the $$ to use my rig for R&D).

Tap Water :shock:.... http://www.freesmileys.org/smileys/smiley-angry009.gif ....... :lol:

How did you go bruggzy ???

Did you compare the products ?? ... Basically, the Nulon concentrate should give you the same thing as a pre-mix Type B coolant with no eth-gly.

If it has minimal or no eth-gly it is a Type B coolant.

A quality brand Type B coolant should have all the anti-foam agents and corrosion inhibitors that a Type A coolant has.

Some brands may sell an "inhibitor" concentrate ... that is only a soluble oil and not the chemical cocktail.

Type A coolant gets percentages of eth-gly added .... and the extra chemicals to keep the eth-gly under control.


For short term use ... and followed by a good flushing ... Its not such an issue ..... but chlorine and all the other council provided goodies ... In a vehicle cooling system ... Over the long term ... No ThankYou ;)


Google ... Aust Std 2108 2004 Type B "coolants" ... suitable for use in cast iron engines ... or any engine for that matter .... but the pooncy alloy ones do benefit a bit from the thicker viscosity of the liquid when a bit of eth-gly is added to the mix ..... as long the radiator size and cooling fans make up for the increased running temps caused by the eth-gly poor heat shedding ability.

The service manual calls for 50/50 eth-gly/water mix because some of the service centres that use the manual have -30* winter temperatures .... and its a northern hemisphere, average, ratio mix suitable for a range of vehicles & engines ... "Average" being the thing that should be most understood.

Its not the "old" eth-gly thats the issue ... its the worn out additives. Basically .. a 5yr "coolant" is only a 2yr, 3yr or 4yr "coolant" if the system is not properly flushed.

http://www.fadzter.com/smilies/thumbsup.gif

Yeah, but Brugz is talking about potentialy mixing what he currently has (i am making an assumtion it is an eth/gly) with this non eth/gly. Want to make sure it is all completly flushed, otherwise the mixing of the different coolants could have adverse results (this is the myth/fact I was refering to). Not so much mixing old and new coolant (like for like).

:cool::cool:

Nah, sorry XJeepers,
At the time, I only had tap water in the rad.**)
Mad, I know, but it was only short term.

My question was about the difference in the two coolants. I already had a new and unopened bottle of NULON, but had found a 'non eth-gly' product and was wondering if it would be better.

Is that a bit clearer? lol.


cheers

Hi, I would like to add my experiance, and paste my first forum article about this,
" I have a 95 xj and sorted my heat problem.
It started after I serviced the cooling system which appears common from US forums.
This got me thinking about 70's mopar mussle cars which had common dramas with water vapor lock in the blocks.
Tried this... Got xj hot carefully removed radiator cap jambed a coke bottle full of water on top of the radiator inlet and pumped the top hose a lot. Fitted in 3 more liters of water!
This sort of fixed it.
Stage 2
Total flush. Put radiator flush in system turned heater on ( important!) and ran it for 20 minutes. Drained system, took off top and bottom hoses and thermostat, flushed in both directions at high pressure for probably an hour same with radiator. Got a heap of brown goo sort of like algea out. Got a hose joiner ( about inch and a quater i think) cut the top hose in the middle of the straight section in the middle and fitted the joiner with hose clamps. Drilled a small c/s self tapper screw in the top of the joiner
Reasembled all and filled with coolant.
Over the next few weeks just undid the screw half a turn straight after a drive and let some air out with Engine hot and turned off. You have to remember to keep the radiator top off tank full as every time it cools down it's going to suck a lot more water in
In answer to probable questions.
No the screw does not leak, you just be gentle with it and the bite at the counter sink keeps it sealed, I did this a year ago and no probs.
The problem was most evident going up a steep hill the temp would go straight up.
This is the problem I think, glycol can promote algea growth, this is why manufacturers suggest radiator flush once a year. With a older car with a poor cylinder head design you can get algea blocking the water flow, if you don't flush the heater as well there if always more algea to grow.
Being totally full of water is not critical but with a very long six cylinder with a fairly high mounted water pump I think what was happening was the system was down about 3-4 liters when just doing a standard fill. When I was going up a step hill the water flowing to the back of the block was exposing the water pump to the air in the block and causing pump cavitation ( this is when the pump impeller grabs some air and just spins this air and steam) so instant over heat as you effectively have no pump. I took the pump off and checked it and there was cavitation pitting on the inside of the pump but not enough to affect it's performance.
Stage 3
I still had a lot of under bonnet heat though the XJ was not over heating this turned out to be cracked headers and a leaking exhaust manifold gasket, I took the headers off and welded them up ... temp fix as they will crack again eventualy but ok so far bolted all back together and it's gone from the top of the bonnet being to hot to hold your hand on, to normal road car temps !"

ok so I need to add, after all this my xj ran cool but the temp would range up and down, plus while my highway fuel ecconomy was very good, around town it was bad, I recently tried the thermostat fix from the one parts places give you here (82deg and $40!) to one from rockauto in the states (95deg and $1.45!!!!) I now run a very consistant temp and this helped my mileage alot along with a few other parts

Must have missed your post Bruggz :%

:hammer:

Crystal :)

fwiw most cooling system are pressurised to 1.1bar, this actualy raises the boiling point of pure water (distilled or ro/di) to 121 deg C, your jeep should not actualy reach this temperature. the coolant additives in this case are not being used to increase boiling point, and are mainly there for anti corosive effects.

This is the latest configuration on the V8 Jeep with the Alloy radiator.

http://i956.photobucket.com/albums/a...s/IMAG0308.jpg

The other setup didn't fit the alloy radiator..

Ive been running my alluminium radiator for awhile now. Did a few trips through summer on beaches and towed a heavy boat on hot days. Only saw approx 100 degrees once when driving on soft sand for 7 km with a 20 knot tail wind.

Temps normally stay around 92. So far temp problems are a thing of the past :)

touch wood!

The temps here now are in the 40's and the V8 Jeep still does not have any overheating problems. I can't remember the last time the fans came on. The temps sit between 79 and 85. Not sure if it is the change to the LS1 or the alloy radiator but temp problems are a thing of the past.. Get an alloy radiator. Bonus is the trans cooler is on the correct side as well..

Just fitted these two vents before relocating to cairns. Very good value, dropped about 5 degrees and has never gone above about 103 since instalation. Even fully loaded up, including roof racks on drive to cairns in 35 plus degrees. Beenliegh to Port Douglas in 24 Hours! To top it of averaged 13.1 L/100 pushed hard. Can't wait to test the vents out on some low range work!

Hey Rodge did you manage to get around to the next installments on this topic? Cant seem to find them (not with Tapatalk topic search at least).

no, havent got that far yet,,,,too much crap going on

After many years (8 approx of my ownership) of running what I can only assume is the original radiator fitted to my car which makes it 16yrs old the old copper/plastic unit had to be changed as it was weeping around where the tanks seal against the core.
So I flushed it all, put in an aftermarket copper/brass unit, fitted a new 192*f thermostat replacing a genuine 195*f (god only knows how old that is as the engine was swapped last year) running a new waterpump and twin electrics it now runs way cooler then it ever did.
When stock or even with the new pump and twin electrics it would sit rock solid on around 95* all day every day, on the highway, in traffic, towing my camper trailer didn't matter, heavy 4wding was the only thing that would make any difference but now the temp is all over the place from just over 1/4 (around 70*) up to the normal 90's range according to the guage, it doesn't look like a lot on the guage but when it never used to move at all it is a little odd.
What I haven't tried yet is my camper on it since the xmas overheating debacle which inspired all these replacements....

Sounds like those fans are cooling the water temp down too much. You could cut down the airflow with a bit of removable plywood, rework the fans or put a piece of tape over the gauge.

The fan mod went in back in about 2009 so I seriously doubt that will be the issue, the first sign of any fluctuation albeit only minor ie you could detect on the guage when the t/stat would open and close was after doing the engine swap but at the same time I had to put in a new temp sensor as it broke but it was minor not like now, if I have the AC on which means the fans are both on full speed the temp stays around the 70 mark, if I leave the AC off the fans run on low speed the temp will eventually come up higher but still not quite to where it used to.
I am thinking it may be the t/stat, I still have the original from my engine even though it is at least 8.5yrs old but was always stable and I still have the t/stat from the new motor which is ??yrs old so it will be interesting to swap them back in and see what happens....

The point I was making is now the rad is super efficient and doesn't require the same amount of air pulled through it to maintain a stable temp. I'm thinking one of those flow restrictors made out of a nylon cutting board would do the trick.

Good point, I will try the thermostat first before modding it....

sounds like the t-stat is stuck open

Sometimes maintenance doesn't help when you replace a perfectly fine working t/stat with a new potentially dodgy one....

When I did the scenic rim trip with the boys from the patrol 4x4 forum my xj was bubbling and overheating with about 2-3 hours of low range offroad hardcore rock crawling work.

The green machine was working hard with those lockers and centipede 31's.

Jason on here (who came out with us for the day) put me onto a tip of folding the wings
back and down from the vents under the bonnet, I did this mod and found it did slightly lower the temps running around at home.

I did not do this on the day.

However I did pop the bonnet on the day and left it on the safety latch for the rest of the day to get the hot air out under his advice.

So what I have done for mine now is left the main guts of the thermostat in and raised the back of the bonnet up with longer bolts and washers to let it get the hot air out at a 25mm raise and it sits on 70 now no matter how hard I push it.

And I do work the green machine. The bonnet raise gets the heat out.

I am also putting twin GU scoops on the bonnet at the front for more flow.




Worked a treat and dropped it from around 110 back to 90.

On Saturday I removed the new Tridon t/stat and fitted my original 8+ yr old t/stat and then proceeded to go away for the weekend, did 630k and the temp was back as stable as ever and at the normal temp range again.....

Good tech thread guys.
Can i get some advice? I just bought my first jeep (95 XJ 4.0 auto) and was wondering what i should do with my cooling system?
Obviously ill make sure its all in top condition (new alloy/plastic radiator just been put in before i bought it)
I live in Newman and we get upto and over 50degC ambients in summer.
We also dont want to overheat and get stranded in the middle of the desert with no phone reception.
so what coolant mix, what thermostat etc should i run?
should i upgrade the radiator? and to what or which brand/type?

I am going to be spending the next month or so replacing and modding most of the car, and reliability is right at the top of my priorities (always as been)
Things like cromoly axles etc are first on the list (as ive heard the rear is prone to breaking), before i get a lift kit etc just for strengths sake.
I was also going to run an external auto cooler, to take some load off the radiator, just haven't found the best place for it yet...

I just want it as "overheat" proof as possible, just like im going to try and make it as unbreakable as possible (may even be getting bigger diffs, think they were 44's, instead of an axle swap)

Thanks in advance guys

Factory Thermo fan
 

Hi all,
My 95 XJ got fairly hot (110) on the weekend after a long climb in low. The rest of the cooling system is in good cond and never usually sits above 95 to 105 in traffic. Can the factory thermo fan be wired with a manual switch so it can be flicked on to aid in cooling even when the air con is not running? If so, is this fairly simple to do?
Regards,
Andrew.

Yes it can, do a search for this as it has been covered before although if the cooling system is in good nic then it shouldn't go over 95 in traffic...

Manual switch for thermo fan
 

Thanks, found it here for anyone else considering the same:
http://www.go.jeep-xj.info/HowtoTaurusFanInstall3.htm

Being it was 41°c here, and I was crawling in peak hour the cooling system got a damn good workout. It sat solid at the first line after 100 on the gauge until we started pointing slightly uphill. Dash went nuts and it jumped up to the first red line.. sat solid there for 10-15minutes. we crested the 'rise' and I turned the heater on at the same time from the AC. Within about 3 seconds the temp dropped back to the first line and sat there. Until home (another 20 mins)

Now I'm home the bonnet was far to hot to grab with bare hands. the overflow was full but not overflowing. The overflow is also literally boiling (i get the pressure raises boiling point bit)

How normal is this for the XJ? a few months ago now ~5000k it got a new rad/clutch/t-stat/waterpump/hoses/cap. I'm guessing to improve on what is there now is the ac switch, trans cooler and what else?

Have I got this right? it was bubbling cause the inlet is at the base of the overflow.

My best explanation was a random air bubble working it's way through... mixed with a somehwhat dodgy rad cap, the temp slammed down when it opened released the pressure and partial air lock ??

Expansion of Large hose leading to Water Pump
 

What does it mean, if the top large hose coming from the radiator leading to the front of the engine (I assume the water pump) has expanded in places?

Does it mean that the water pump is on the way out or has died?

There is no sign of a leak so far.

I opened the bonnet after experiencing a 115 deg C climb which came back down to 100 deg C when the aircon was switched on - a departure from the regular 95 - 105 deg C range.

Is there a blockage somewhere that is causing this expansion?

I haven't really noticed the expansion of the hose before but only did so when I hadn't switched the aircon on and the car was still hot.

The radiator was changed about 7 years ago, not that it needed changing back then, but the stealer could not find the source of a coolant leak - it wasn't the radiator.

What is the typical cost of an XJ waterpump and thermostat and labour?

To clarify - the hose had expanded between the sleeve protecting it from the pulley and the water pump. The rest of the hose was its regular size. I had another look at it now that the engine temp is cooler and the area of expansion went back to normal size.

At the time I stopped the engine running, I could smell a disc brake type smell coming from the wheel area but it could have been the disc brakes.

I'd be replacing that hose man. Sounds to me as though it's gone soft.
Did it blow up, like a balloon?
Was it the top hose or bottom hose?
Does the overflow work? Perhaps the radiator cap isn't releasing pressure.?