Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Radiators keep blowing up ?

Thread Tools
 
Search this Thread
 
Old Nov 19, 2017 | 08:43 AM
  #16  
Poodle Head Mikey's Avatar
Thread Starter
Member
 
Joined: Dec 2016
Posts: 150
Likes: 0
From: West Florida
Year: 1998
Model: Grand Cherokee
Engine: I6 - 4.0
Default

Thanks. I'm off to Auto Zone first thing this morning.

Changing the radiator cap pressure does raise the question: I wonder how low is "too low" ? I can remember when a 7 lb. radiator cap was pretty standard. Now cars back then ran 170-180º thermostats - and over 210º was considered as "overheating" - but this Jeep does not run hot. I wonder what would happen if I used a 5-6-7 lb. radiator cap? <g>

PHM
----------






Originally Posted by Bugout4x4
I would go to a 14 no matter what they tell you. And if it spits fluid out, then you have other problems because it shouldn't at all with even a 14. Like I say, I am running a 13 lb in 125 degree conditions without any problems at all.
Reply
Old Nov 19, 2017 | 08:50 AM
  #17  
Bugout4x4's Avatar
CF Veteran
 
Joined: May 2015
Posts: 4,481
Likes: 18
From: Arizona
Year: 97
Model: Cherokee
Engine: 4.0
Default

Originally Posted by Poodle Head Mikey
Thanks. I'm off to Auto Zone first thing this morning.

Changing the radiator cap pressure does raise the question: I wonder how low is "too low" ? I can remember when a 7 lb. radiator cap was pretty standard. Now cars back then ran 170-180º thermostats - and over 210º was considered as "overheating" - but this Jeep does not run hot. I wonder what would happen if I used a 5-6-7 lb. radiator cap? <g>

PHM
----------
I think 14 is about as low as you want to go on these. A certain amount of minimum pressure does indeed help raise the boiling temperature a bit to help prevent overheating and like you say these do run quite warm already as a norm. But when they started this high pressure system trend radiators were still all metal and able to stand higher pressures better than these plastic radiators. Just imagine how much these are "ballooning" and contracting back every heat up to pressure cool back down cycle. It's a wonder they even last two or three cycles in the first place. lol
Reply
Old Nov 19, 2017 | 08:55 AM
  #18  
Bugout4x4's Avatar
CF Veteran
 
Joined: May 2015
Posts: 4,481
Likes: 18
From: Arizona
Year: 97
Model: Cherokee
Engine: 4.0
Default

Originally Posted by Poodle Head Mikey
Thanks. I'm off to Auto Zone first thing this morning.

Changing the radiator cap pressure does raise the question: I wonder how low is "too low" ? I can remember when a 7 lb. radiator cap was pretty standard. Now cars back then ran 170-180º thermostats - and over 210º was considered as "overheating" - but this Jeep does not run hot. I wonder what would happen if I used a 5-6-7 lb. radiator cap? <g>

PHM
----------
Something else to remember... Those guys at the store are in the business of selling radiators. lol
Reply
Old Nov 21, 2017 | 07:00 AM
  #19  
Poodle Head Mikey's Avatar
Thread Starter
Member
 
Joined: Dec 2016
Posts: 150
Likes: 0
From: West Florida
Year: 1998
Model: Grand Cherokee
Engine: I6 - 4.0
Default

Yes; but with a lifetime warranty on them it seems counter productive to their best interests to have the radiators repeatedly fail. <g>

PHM
---------


Originally Posted by Bugout4x4
Something else to remember... Those guys at the store are in the business of selling radiators. lol
Reply
Old Nov 21, 2017 | 07:07 AM
  #20  
Poodle Head Mikey's Avatar
Thread Starter
Member
 
Joined: Dec 2016
Posts: 150
Likes: 0
From: West Florida
Year: 1998
Model: Grand Cherokee
Engine: I6 - 4.0
Default

The engine is fairly new and runs cool and the antifreeze always looks pristine - if that is any indication of flush-requirements.

But when you say: "maybe water pump issue" - do you mean that a problem with the pump could possibly be resulting in excess cooling system pressure?

It's an interesting possibility but it's not really that kind of pump - it's a circulating-type pump rather than a pressure-developing pump.

Do you have any direct knowledge that the water pump could be overpowering the system? I can tell you that the radiator originally blew out right after the water pump was replaced. <g>

PHM
--------


Originally Posted by SirCyber
Sounds to me like you might need a flush. It certainly won't hurt anything to do it. Also maybe water pump issue?
Reply
Old Nov 21, 2017 | 07:15 AM
  #21  
Bugout4x4's Avatar
CF Veteran
 
Joined: May 2015
Posts: 4,481
Likes: 18
From: Arizona
Year: 97
Model: Cherokee
Engine: 4.0
Default

Originally Posted by Poodle Head Mikey
Yes; but with a lifetime warranty on them it seems counter productive to their best interests to have the radiators repeatedly fail. <g>

PHM
---------
One might think so... but this isn't quite how it works. Having a much higher pressure cap listed as the replacement on models where it is truly not needed blows up twenty times more radiators that are not yet under warranty first.

They make a replacement profit off of everyone of these that might not have blown up. Then they don't personally foot the bill on the warranty, the maker of the radiator does. So it is a win win for the part houses to sell caps that blow up radiators.

I have worked in part stores and this is a constant battle between the part manufacturers and the retail stores who offer the warranties.
Reply
Old Nov 21, 2017 | 07:21 AM
  #22  
Poodle Head Mikey's Avatar
Thread Starter
Member
 
Joined: Dec 2016
Posts: 150
Likes: 0
From: West Florida
Year: 1998
Model: Grand Cherokee
Engine: I6 - 4.0
Default

Can you expand on that concept for me please? How would the radiator have to be mounted incorrectly in order to create a failure scenario? It makes sense if you picture a distortion of the radiator's structure - inducing a 'twist' or something like that.

I would like to mention that in both cases the radiator failure occurred right after the radiator was re-installed. <g> Although . . . I do treat the SOB's like fragile eggs whenever I am handing/dealing with them. <g>

On counter-point: the radiator install / mounting is very straight forward. Two insert/locator pins at the bottom, the top locating bracket with it's four 10mm bolts and two nuts, and the u-brackets in front of the condenser. Then the shroud is located to the radiator with two small locating widgets at the bottom of the radiator core and two 10mm bolts horizontally through side tabs with clip-nuts.

But . . . . Suppose something in the front of the truck is distorted? Some un-noticeable mis-alignment between the various attachment points? It's not as though the radiator bolts down to a flat surface.

What was in your mind when you wrote this: "radiator not mounted correctly" ?

PHM
--------

Originally Posted by Turbo X_J
Radiator not mounted correctly.
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



All times are GMT -5. The time now is 09:12 AM.