Water pump question...

I had my water pump replaced about six months ago. I've heard that there are two diffrent kinds of water pumps for the xj, two diffrent flow directions. Is this true? If I have the wrong one would it explain why I have no heat and my jeep runs about 10-15 warmer than usual? It only a 99 but I've almost replaced the whole cooling system.. (still no heat). Thanks for any info in advance!

Adam

You can find and download a parts manual at xjjeeps.com
There were only two pumps available. One was for the 4 cylinder engine, and the other was for the 6 cylinder engine.

There are many reasons that heat will not work. However, the most likely is a clogged heater core. Do a search here for flushing a heater core. You’re probably going to get a lot of sludge out of it.

Good Luck!

-cp

adam.gutt said:

I had my water pump replaced about six months ago. I've heard that there are two diffrent kinds of water pumps for the xj, two diffrent flow directions. Is this true? If I have the wrong one would it explain why I have no heat and my jeep runs about 10-15 warmer than usual? It only a 99 but I've almost replaced the whole cooling system.. (still no heat). Thanks for any info in advance!

Adam

Click to expand...

There is only one type of water pump for the 4.0 and it's reverse flow i.e. it spins counterclockwise. It's unlikely you have the wrong one.
The lack of heat could be down to one of three things; thermostat stuck open, heater valve stuck open, or heater core clogged with leaves and other dirt.

There are in fact 2 water pumps that will "FIT" the 4.0...one has a long snout and the other is almost flat. Both of them will fit the cavity on the front of the block. Ask me how I know

BillyBob said:

There are in fact 2 water pumps that will "FIT" the 4.0...one has a long snout and the other is almost flat. Both of them will fit the cavity on the front of the block. Ask me how I know

Click to expand...

Yep one for AC and one without AC but the wrong one won't line up with the belt.

adam.gutt said:

I had my water pump replaced about six months ago. I've heard that there are two diffrent kinds of water pumps for the xj, two diffrent flow directions. Is this true? If I have the wrong one would it explain why I have no heat and my jeep runs about 10-15 warmer than usual? It only a 99 but I've almost replaced the whole cooling system.. (still no heat). Thanks for any info in advance!

Adam

Click to expand...

Has the thermostat been replaced recently as well?

Flush the heater core, and make sure the blend door is working properly. I don't think the 99's had a heater control valve, but if by some chance yours does, just cut it out and bypass it. Those valves SUCK, my heat was 100x better once I threw the thing in the trash.

Possible SPOBI alert: I can't find the thread where I remember seeing this, so take it for what it's worth. With that out of the way:

I believe that the water pump for an AMC 258 engine (i.e., the 4.2-litre straight-six used in various CJs, YJs, FSJs, and Eagles) would fit the 4.0 but rotated the wrong direction; someone found this out the ward way from what I remember.

Not trying to post bad information, but really can't find the thread where this was discussed. If someone could correct this if it's wrong it'd be appreciated.