Open or Closed system -Cooling?

[97RedXJ]

I have a 97 with the 4.0. it has about 40k on motor. I have been having some cooling issues and i search but not sure of the difference in open or closed cooling. I have a 180 t-stat but its running at 215? Anti Freeze is hyper neon green so i am not sure what to do. How would i know or check the water pump?

I could use any help.
Thanks

[shortxjdoug]

first off it is an open cooling system, the renix or pre 1991 injection system, was a closed cooling system. i would look at the radiator depending on if its come from a rusty state, mine ate its second at 140K but it came from ohio before i bought it. As for the water pump i'm not an expert at diagnosing those but listeneng for any bearing trouble would be my first guess, i've always just replaced mine when they blew out in my 83 cj

[NSW Sparky]

Wow only 40,000 on a 97 my 96 has about 130,000
215 is pretty close to normal.
If your radiator looks like mine it is shot.

http://img.photobucket.com/albums/v47/NSW_Sparky/new%20stuff/PICT0078.jpg

[meatplow5150]

I have a 97 with the 4.0. it has about 40k on motor. I have been having some cooling issues and i search but not sure of the difference in open or closed cooling. I have a 180 t-stat but its running at 215? Anti Freeze is hyper neon green so i am not sure what to do. How would i know or check the water pump?

I could use any help.
Thanks
A cooler thermo won't keep you from overheating. All it does is allow coolant to flow at a lower temp slowing the engine from reaching normal temp (210*).
I'm no expert, but based on my own recent experience, I would NOT consider 215* to be too hot.

[97RedXJ]

Wow only 40,000 on a 97 my 96 has about 130,000
215 is pretty close to normal.
If your radiator looks like mine it is shot.

http://img.photobucket.com/albums/v47/NSW_Sparky/new%20stuff/PICT0078.jpg


It has 158K on it but it blew so i put a newer one in from a 2000 TJ with about 35k on it.

[meatplow5150]

It has 158K on it but it blew so i put a newer one in from a 2000 TJ with about 35k on it.

A TJ radiator in an XJ??? :looney:

[shortxjdoug]

It has 158K on it but it blew so i put a newer one in from a 2000 TJ with about 35k on it.

yah i don't see how that is worth the swap a new rad is 150 bucks. :dunno:

[RCP Phx]

Read his post,He put a 35K mile motor from the TJ in,not the radiator.

[5-90]

215 is supposed to be "normal" operating temperature for the AMC242 - it's spec'd for 210-215*F. Granted, this can be changed, with a little work (my 88 and my 89's all run down aroun 190-195*F, but I'm cranky.)

The relatively long cooling tubes in the XJ radiator do NOT respond well to buildup in them - flushing every two years is something I'd consider MANDATORY. Use a good strong flush the first time YOU are doing it (you don't know what's been done to it before then, do you?) and then you can probably get away with a gallon of vinegar and top of with water to flush afterwards.

If this is the first time YOU have flushed the cooling system, I'd also advise changing ALL the hoses AFTER you flush - you'll free up a lot of crap in there, and changing the hoses will help to get the rest of it (and, you'll know how long your hoses have been in service. I won't leave one go for more than five years...)

Also, if you start seeing "heat creep," note WHEN it happens. Typically, you'll see the heat go up at idle and drop at speed, which usually indicates a fan clutch. These are good for four years MAYBE, and are easy to replace.

5-90

[MaXJohnson]

I have a 97 with the 4.0. it has about 40k on motor. I have been having some cooling issues and i search but not sure of the difference in open or closed cooling. I have a 180 t-stat but its running at 215? Anti Freeze is hyper neon green so i am not sure what to do. How would i know or check the water pump?

I could use any help.
Thanks
Some details would be helpfull.

When does it overheat? Freeway driving, stop and go, idle, heavy load(hills/towing). What have you done so far? Winter/Summer/Spring/Fall?

With 155K, I assumed every part of the cooling system had seen better days. I replaced the radiator, water pump, fan clutch, electric fan, thermostat, cap and hoses, plus a flush and new coolant. Pretty much a cooling system rebuild.

The result is obvious on a recent 3 hour drive across Missouri:
http://home.everestkc.net/alynloya/97_XJ_temp_graph_06042006.jpg

If you don't want to go through the whole system, you need to determine under what circumstances the system overheats in order to narrow down the possibilities. Without more info, it would be foolish to offer a cure. The problem in my case was overheating at low speeds and while stopped. The cause was a defective electric fan. It would come on when expected, but wasn't pulling the CFM's that it should have. Not easy to detect and rarely considered.

[97RedXJ]

A TJ radiator in an XJ??? :looney:


Nope, not a TJ radiator it's still the XJ one.

[97RedXJ]

215 is supposed to be "normal" operating temperature for the AMC242 - it's spec'd for 210-215*F. Granted, this can be changed, with a little work (my 88 and my 89's all run down aroun 190-195*F, but I'm cranky.)

The relatively long cooling tubes in the XJ radiator do NOT respond well to buildup in them - flushing every two years is something I'd consider MANDATORY. Use a good strong flush the first time YOU are doing it (you don't know what's been done to it before then, do you?) and then you can probably get away with a gallon of vinegar and top of with water to flush afterwards.

If this is the first time YOU have flushed the cooling system, I'd also advise changing ALL the hoses AFTER you flush - you'll free up a lot of crap in there, and changing the hoses will help to get the rest of it (and, you'll know how long your hoses have been in service. I won't leave one go for more than five years...)

Also, if you start seeing "heat creep," note WHEN it happens. Typically, you'll see the heat go up at idle and drop at speed, which usually indicates a fan clutch. These are good for four years MAYBE, and are easy to replace.

5-90


Yeah at idle it does tend to creep up but not too much higher then 225* Then after a mile or so of driving it goes down to 210 roughly. I will look into a fan clutch. Thank you and everyone else for there help!