Yet another "My XJ Runs HOT" Post

[rainman]

Originally Posted by eksjay

Yeah, I dunno what to make of it. I bought the 95 XJ sport new in ... well 1995. I replaced the first OEM rad in 2008 with another OEM rad. Stealer said it failed the pressure test (I was losing coolant with no noticeable leak). With a new OEM rad, it still leaked coolant. Then stealer replaced the coolant bottle ... still leaked. Then they replaced the overflow hose. Fixed.

In 2015, same thing happened. I replaced the OEM rad with the Adrad. I am all in favour of using Aussie parts, but this is ridiculous! There were mystery drops in the coolant tank from day 1 of the first Adrad. I was afraid that this coolant was exiting through the exhaust gases although the engine is flawless in its performance. There are no milky residues on the dipstick.

Then the mechanic shows me the shot Adrad removed from the engine bay. They suggested that the thermostat could be playing up, but I am unsure how? It is operating at around the 97 degree C to 104 C range.

Richard, you suggested a cap replacement. It is a new cap. Maybe I should replace the overflow hose (possible minute perforations)? With a newly replaced Adrad, I am about to pour new coolant into a completely empty overflow tank. I expect that the fluid will fall before too long...

I had a weeping welsh plug that was causing coolent loss, cause it had rusted through.
Their is also a welsh plug on the back of the head that can corrode and weep.
I also orderd a black light tourch from on eBay from China for like $5 delivered makes spotting coolent leaks, even small obscure ones, easy.
Good luck with it.

[werd]

Originally Posted by rainman

I also orderd a black light tourch from on eBay from China for like $5 delivered makes spotting coolent leaks, even small obscure ones, easy.
Good luck with it.

This sounds interesting. How did you do this?

I'm not fixing it, I'm improving it!

[rainman]

Originally Posted by werd

This sounds interesting. How did you do this?

I'm not fixing it, I'm improving it!

Not to sure exactly what u are asking but here goes.
Most coolents contain a fluorescent die, when illuminated but uv light it glows, or fluoresces.
So when you shine a black light into the engine bay (esp at night)any leaks, still wet or even ones that have dried, stand out like the proveribal dog balls.

So all you need is a black light source, you can get light bulbs that will go in your inspection lamp, but a tourch for less than $5 bucks deliverd from China- seemed easiest and cheapest option- you do have to wait a month for it to arrive though.

Sometimes the ac system has a fluorescent dye in it to help with leak detection as well.

On a side note, Shining a black light around yr back yard at night can be interesting. Also if you have young boys, shining it around the toilet at night is a bit of a eye opener 😁.

http://www.ebay.com.au/sch/Camping-H...+torch&_sop=12

Hope that answers the question.

[Roler]

Haha, yep, there r things to do and better not to do with a blacklight

[LuluBelle]

I remember in one of my posts I said that on the way home from Barcaldine when I had the temp worries I said that the revs went up around 200 rpm under cruise control now I have been thinking and please tell me if I am wrong........
I have started another thread to talk about camshaft angle sensor starting to fail
could these two be related????
my theory when I got hot and the revs went up I went out of cruise control and sorta thought I was in 3rd gear I sorta dismissed it but after reading about crank angle sensors or cam angle which ever you prefer I have these symptoms
3 - Acceleration Hesitation

This is also similar to the cylinder misfiring. If there is some type of hesitation in acceleration, then the computer is not getting the correct information on the position of the cylinders when the car is running. There is a lag between the computer receiving data from the crankshaft position sensor and applying it, so it takes the car that little bit of time to accelerate.

7 - Irregular Car Function

Basically you will notice that regular engine workings will start to become irregular, such as speed fluctuations, irregular acceleration, idling fluctuations, and more. If you start to notice a lot of odd and irregular workings then have your crankshaft position sensor checked

Now if I was having "irregular workings " and I read some where else the auto gearbox could get involved So I was in the wrong gear revs were high engine under load and maybe not running as efficiently as it should that would drive the temps up? even on a good cooling system

[rustynuts]

Originally Posted by LuluBelle

I remember in one of my posts I said that on the way home from Barcaldine when I had the temp worries I said that the revs went up around 200 rpm under cruise control now I have been thinking and please tell me if I am wrong........
I have started another thread to talk about camshaft angle sensor starting to fail
could these two be related????
my theory when I got hot and the revs went up I went out of cruise control and sorta thought I was in 3rd gear I sorta dismissed it but after reading about crank angle sensors or cam angle which ever you prefer I have these symptoms
3 - Acceleration Hesitation

This is also similar to the cylinder misfiring. If there is some type of hesitation in acceleration, then the computer is not getting the correct information on the position of the cylinders when the car is running. There is a lag between the computer receiving data from the crankshaft position sensor and applying it, so it takes the car that little bit of time to accelerate.

7 - Irregular Car Function

Basically you will notice that regular engine workings will start to become irregular, such as speed fluctuations, irregular acceleration, idling fluctuations, and more. If you start to notice a lot of odd and irregular workings then have your crankshaft position sensor checked

Now if I was having "irregular workings " and I read some where else the auto gearbox could get involved So I was in the wrong gear revs were high engine under load and maybe not running as efficiently as it should that would drive the temps up? even on a good cooling system

This is my understanding. Please anyone to correct me but.. The car needs the crank angle sensor to start. If it fails while the engine is running the engine will still run but off the camshaft sensor. When this happens the engine batch fires the injectors instead of in sequential order.
Well then this is irregular workings. It may make the trans to do "other things ?". That can effect temps.
Just a thought.

[layback40]

Revs going up by 200 at a given speed sounds like torque converter unlocking. I really think you need to get a good mechanic who knows jeeps to have a good look at it & stop trying to diagnose over the internet.