Hey there, I'm just bought a stock '01 XJ, everything seems fine. The only thing bothering me is when I get up to 4th and 5th gear(NV), there is weird slushing noise like air or water is coming in somewhere, it sounds like a flushing toilet. The noise comes from the engine/behind the dash.

I would really appreciate some help

 

Could be your heater core is air locked and coolant is sloshing around. Or the a/c evaporator drain tube is plugged up and condensation is building up and sloshing around.

 

Could be the sound of your coolant reservoir tank refilling itself. Check your coolant leval and make sure it is not low. Do not check it when it is hot if it is a closed system. Wait until the engine is cold before you check it.

 

Thanks I will check it.

 

Will check it out, probably will flush all fluids to see if it improves.

Thanks