91 KA-24DE Cooling Issues (help!)

[SixxTwo]

Replaced water pump and thermostat at the same timeas the old water pump had gone bad.

My belief is that either the new thermostat isnt opening, or the belt on the water pump may? not be tight enough.

I believe that the belt is fine more then the thermostat. I get heat thru the system so I'm fairly sure the water pump is working. Also, I can feel the heat from the heater getting warmer as I drive. (and warmer as it overheats)

I have boil tested the new thermostat and it does open (not sure on the exact temp tho)

plus while test driving it the temp fluxed quite a bit... I took it out for a time and it was fine... then the temp went up higher then I was really comfortable with then went back down to normal.....then it did it again, except it didnt go back down, so I made a quick run to the backyard =D

Never really had this issue before I changed these parts.thermostat is in the correct way.

Also how would coolant get onto the other side of the thermostat to open it? I poured it into the outlet (upper) side of the block but Im not sure if that is enuff or if there is air in the system

Also the hose on the thermostat intake side (bottom hose) isnt even warm at all. which further makes me think the thermostat isnt opening

I have no clutch fan, but have wired the electrical one to constant, as in on of the installs area

So any Ideas?

Belt? Belt tensioner? Bad Thermostat? fan not enuff?

Help! I gotta go back to work on monday



Sixx
Modified by SixxTwo at 5:53 PM 9/23/2006

[Florida240sx]

Sounds like your fan....Remoce your thermostat for now and see hwo your car does.. You don't need it, but you got the let your car sit for minute so everything warms up. Or just drive easy until operating temp...I'd say it's fan issue as well, get 2 electric fans or a single like a 350z fan, flow some good air to get it pulling/pushing. I'd do upgraded fan first... When your car is at operating temp feel to see if thermo is opening... if it is then it's just your fan issue

[rogoman]

You may have air pockets in the coolant system.

Your best bet may be to drain down the coolant and start all over again with the filling of the coolant. Here's how I do it:1 - drain coolant2 - open the bleeder screw3 - optionally jacking up front of car helps to purge air pockets4 - fill system until coolant starts coming out the bleeder hole5 - close bleeder screw (not too tight; screw is easy to break off)6 - continue filling until coolant is at the bottom of the filler neck7 - do not put cap on the radiator8 - start motor; as coolant starts to warm up, you may see a few air bubbles9 - squeeze the hoses by hand to free up possible air pockets10 - put cap on radiator

Also what type of thermostat did you install; if it was some aftermarket piece of crap, then you may end up with more problems then need be; install a Nissan OEM thermostat and make sure the 'steam' hole is at the top.

[Florida240sx]

Where is the bleeder screew??I always just topped her off squeezed the pipe, Start the car and squeeze the pipe and as fluid get low add more until it heats up and got to put the cap on.Let it run for about 60 shut off, wait to cool add more etc...Worked for me........and my friends