4.0l XJ overheating? Start here - the basics!

[carvesdodo]

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 ......

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 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 ... 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



Another point made in the link is the increasing of flow rates to make up for the deficiencies in eth-gly mixes.

Noooo .... bling bunnies ... 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

...... 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 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 ....

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

[tazwegion]

Great thread guys!


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)

[tazwegion]

Originally Posted by Rodgebone

grocery stores dont sell distilled water in Taz?

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

[dazza96]

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

[bruggz351]

Ok, I am ready to replace the coolant (Tap water ) 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)

cheers

[XJeepers]

Originally Posted by bruggz351

Ok, I am ready to replace the coolant (Tap water ) 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)

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).

[carvesdodo]

Originally Posted by bruggz351

Ok, I am ready to replace the coolant (Tap water ) 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?

Tap Water .... .......

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.

Originally Posted by XJeepers

Wouldn't use anything but demineralised water myself.

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

Originally Posted by XJeepers

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.

Originally Posted by XJeepers

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.

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.

Originally Posted by XJeepers

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).

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.