I'm thinking about replacing the water pump on my '91 XJ and just wondering if the sever duty/heavy duty water pump that is available is worth getting? It's only about $10 more so it seems like a no brainer, just wondering why there are even two different options for the water pump. Was the heavy duty pump a factory option?

My jeep runs warm when stopped at idle, fine when moving. I'm going to replace the fan clutch first, but I think the water pump may be on it's way out as well... I have a chirping sound when the engine's cold that seems to be coming from the pump. We have warm weather on the way so I want to make sure the jeep will have no cooling issues...

 

A heavy duty water pump might move more fluid. It is ultimately up to you since it's your money. IMO I would take that $10 and pick up a 180* thermostat.

 

$10 bucks wont hurt for a severe duty water pump and its recommended to change the fan clutch with the water pump, you can get a 180 degrees thermostat and if in a budget flush the cooling system, all together will guarantee you an almost as good as new cooling system!

 

I installed a new fan clutch yesterday, seems to have helped a little bit, the temp doesn't climb nearly as fast while idling at lights, but it still creeps up over 210 eventually. I'll probably replace the pump today and flush the cooling system.

 

I would replace the water pump and the thermostat as well as using good coolant with an additive such as RedLine Water wetter. I have used it in the past and I think it works great. There are others out there now, such as Royal Purples. I have heard good things about there coolant additive as well.

 

Are you still running a closed system?

 

Not to "jack" the thread but what does additive's such as "RedLine Water wetter" do for the coolent syestem?

 

Brings the boiling point of the water higher and dissipates heat better IIRC.

 

Cool, thanks Gee. I geuss I better get some of that.

 

For 20$ why not do both?

 

I talked to my parts guy at Napa and he said the 'severe duty' pump is not actually higher flow, it just has an upgraded bearing. Seems like a good idea, but since they only make them as remanufactured pumps, he recommended going with a new standard type pump, which should ultimately be more reliable.

I'm sticking with a 195* thermostat which is the OEM temperature. Where I live in there's really only a 3-4 months a year where it gets over 70*, plus the Jeep is a daily driver and won't be doing a ton of slow trail crawling, so I shouldn't need a crazy cooling system, just something that works properly. I kind of want to try the Water Wetter though just because it seems like a neat product. Thoughts on that?

This is my '91 I'm working on so it already has an open cooling system... I did swap to an open style rad on my '87 though and it was well worth it to get rid of the stupid pressure bottle. Definitely something I'd recommend to anyone with a Renix XJ.