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Who Makes Upgraded Water Pumps?

People say high flow water pumps are bad because they dont allow enough time for the coolant to cool in the radiator. I think Hesco makes one though.
 
yeah i just found the gojeep link to the hesco ones...

It seems my jeep won't keep cool at idle, as soon as i step the rpm up a little it drops to normal right away. I've changed...well....everything.
 
WheelinJR said:
yeah i just found the gojeep link to the hesco ones...

It seems my jeep won't keep cool at idle, as soon as i step the rpm up a little it drops to normal right away. I've changed...well....everything.

You may be looking at a new water pump, but I doubt you'll need a "high-flow" one (and you can make one yourself from an OTS part for cheaper than you get one from HESCO anyhow. I think they're a bit "proud" of their part...)

Could you detail what you've changed? I'd like to see if I can't come up with something you may have missed, but as I like to say to people - "I'm psychotic, not psychic!" Tell me where you've been and what you've done about it so far, and I'll let you know if you may have missed anything. Deal? (Oh, it would help to know what year your rig was as well... Who's to say you don't have more than one?)
 
WheelinJR said:
yeah i just found the gojeep link to the hesco ones...

It seems my jeep won't keep cool at idle, as soon as i step the rpm up a little it drops to normal right away. I've changed...well....everything.
When you're not moving the only thing providing airflow is/are the fans so the aux. fan should go off. If its going over 230F then you have a problem though. By running the mech fan with no load (i.e. in neutral) then you can cool it off at a stop if thats what you mean by the rpms up.
 
5-90 said:
You may be looking at a new water pump, but I doubt you'll need a "high-flow" one (and you can make one yourself from an OTS part for cheaper than you get one from HESCO anyhow. I think they're a bit "proud" of their part...)

Could you detail what you've changed? I'd like to see if I can't come up with something you may have missed, but as I like to say to people - "I'm psychotic, not psychic!" Tell me where you've been and what you've done about it so far, and I'll let you know if you may have missed anything. Deal? (Oh, it would help to know what year your rig was as well... Who's to say you don't have more than one?)

I did it all in one run...thermostat, hoses, serp belt, fan shroud (yeah i broke it), waterpump. I did this a few months back and ended up with a 180 t-stat accidentally so I did that project twice.

I have my fan on override, and even with it running at idle it'll get way up there. I'm usually very concious of it, but I've looked away long enough a couple times for it to be up where I'd estimate is the 240-250 range.

As soon as you give it a few more rpm's than idle, it will settle right back down (like 1000-1100rpm will do it.)

This is on my 91, only one I've got.
 
WheelinJR said:
yeah i just found the gojeep link to the hesco ones...

It seems my jeep won't keep cool at idle, as soon as i step the rpm up a little it drops to normal right away. I've changed...well....everything.

fan clutch?
 
WheelinJR said:
I was under the impression that I would encounter different symptoms with that problem.

Not necessarily. A fan clutch is, natch, a "viscous" clutch (rather than a direct mechanical coupling.) Therefore, it allows the fan to spin at a percentage of the crankshaft speed (which is divided slightly by the size difference between the crank pully and idler pully, but let's leave that alone for now...)

When you sit at a stop and run up your idle in Neutral, you're letting the fan spin at the same percentage of a faster basic speed. Say it's running at 70% of driven speed - 30% of 1500rpm is still twice as fast as 30% of 750rpm, so you're going to have a faster fan.

I've also noted that fan clutches seem to be good for about four years - five tops! - on an XJ. So, if you haven't replaced it yet, you probably should (and take a Sharpie pen to write the date on the new one when you put it in - it will simplify troubleshooting later. A good idea for most "maintenance" parts...)

There should be no difficulty with your 1991 using a 180* thermostat - that just means it opens to circulate coolant earlier. Slightly longer warmup times may result, but you shouldn't have any trouble other than that.

You shouldn't have caught an air pocked with your 1991 either - and it's not presenting as something like that anyhow.

Change the fan clutch - that's the first place I'd look. You've already done the fan override - even though the mech fan seems to move more air - but the symptoms indicate a fan clutch to me (I'm also going to assume that, since you had your cooling system torn to bits anyhow, you've already flushed the crud out of the system as well?)
 
5-90 said:
You've already done the fan override -

what is the fan override?
 
Actually in the winter my 180 t-stat the jeep wouldnt ever get warm enough. Made for cold drives as the heat didnt work well.

by fan override he means the secondary fan to a toggle switch.

If its gonna come down to fan issues, I'll be eliminating the mech fan completely eventually.

Sniggs: cowling?
 
WheelinJR said:
Actually in the winter my 180 t-stat the jeep wouldnt ever get warm enough. Made for cold drives as the heat didnt work well.

by fan override he means the secondary fan to a toggle switch.

If its gonna come down to fan issues, I'll be eliminating the mech fan completely eventually.

Sniggs: cowling?
The plastic fan shroud around the mech fan.
 
IslanderOffRoad said:
what is the fan override?

It allows you to run the auxiliary electric fan at will. It's done differently for different years - so, what year is your rig?

It's easiest on RENIX, since it's essentially a standalone circuit. Later models (OBD-I and OBD-II) get a little more difficult - but not impossible. You just need more parts to make the thing work.

Anyhow, overriding your electric fan to ON will allow you to move more air at idle or low speeds (because the extra fan is running) - which can delay overheating, or eliminate it entirely. Delaying it is more common, tho... The best way to reduce the risk would be to install the "Extended Idle" switch on OBD-II XJs (it's an option hardwired into the ECU, and the switch was installed on "Police Package" vehicles) since that spins the mechanical fan faster - moving much more air!
 
90exjay said:
Best way to tell if fan cluch is bad?Does it not move at all at idle?

Sean

Symptoms largely like those described. It's difficult to actually "test" function on a fan clutch as an isolated part.

Usually, the problem is either that the viscous fluid breaks down (which is diagnosed through symptoms,) or that the viscous fluid leaks from the clutch (which can be spotted visually.)
 
I remember somebody was buying the HESCO high flow pump but when he called they told him that there was no need for that upgrade because he had the NEW STYLE water pump on his TJ but cant really remember which year DC upgraded to that water pump
 
5-90 said:
It allows you to run the auxiliary electric fan at will. It's done differently for different years - so, what year is your rig?

It's easiest on RENIX, since it's essentially a standalone circuit. Later models (OBD-I and OBD-II) get a little more difficult - but not impossible. You just need more parts to make the thing work.

Anyhow, overriding your electric fan to ON will allow you to move more air at idle or low speeds (because the extra fan is running) - which can delay overheating, or eliminate it entirely. Delaying it is more common, tho... The best way to reduce the risk would be to install the "Extended Idle" switch on OBD-II XJs (it's an option hardwired into the ECU, and the switch was installed on "Police Package" vehicles) since that spins the mechanical fan faster - moving much more air!

I've got a 94.
 
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