My 92 GXE has a sound of water movement (slushing) coming from behind the dash for a few miles each startup when car is turning. I've bled cooling system thinking air could be trapped in heater core but no help. Any ideas?

 

yea i have that same noise ... it hasnt hurt anything yet ... and its been happening for a while now ... i dont know what to do either ??

 

I had this a few times - when I first accelerated to 50km/h in the morning for a few seconds. This is coming from the heater core and I am convinced but I may be wrong, that it indicated a possible air lock, though I had enough heat. This is gone and never returned after I got timing belt replaced and my mechanic spent half an hour pouring antifreeze into the system getting rid of the air lock.

 

Yep, same here. I guess i have a large pocket because my heat sucks. I'm thinking of trying to dissconnect the radiator brackets and lift the radiator up a few inches so i can purge the air bubbles. That way it will be higher than the heater core. It makes more sense than trying to raise the front of your car 3 1/2 feet.

 

i been thinking of the exact same thing since yesterday...although i got some of my heat back after the steep hill adventure. I wonder how easy would it be to have the fans and the whole set up out like that...and how to hold it there when it gets hot.

i paid the nissan dealer 40 bucks to raise the front and do the bleeding from the TSB procedure....two things happened...after that, i lost whatever heat that was coming..and...they wrote me up an estimate of 800 bucks to change the "plugged" heater core.

so i used the TSB and parked the car on a hill and did the procedure and got quite a bit of my heat back...it gets decently warm inside now. but not as much as it should.

 

Could somesome post the TSB so I can try it to cure my problem - water sound and poor heat, its getting cold!

 

http://maxima.theowensfamily.com/tsb...=1989&tsb=none

 

Hey Paul, i found this list of TSBs for the maxima...check out the heater bleeding procedure...that procedure is back from 1989...looks interesting. (its in PDF format)
http://e-toolbox.com/ads/rq.cfm

 

OK. here's what I did last night after installing an inline coolant heater and flushing and filling the system.

Drove the car up on ramps. You know those metal ramps you get at auto parts stores? Don't know if it 3 feet high but it was way more than level. Removed the bleed screw (on the VG it's on top of the intake at the back right - just above where the heater hoses leave the motor and head to the firewall - different for the VE). Poured coolant in slowly until it started coming out of bleed hole (get a large catch pan for under the motor. Since I was changing from regular to long life, I just kept pouring (quite a lot actually) into the rad until the coolant exiting the bleed hole turned from green to red. I figure I poured cold coolant into the warm system...the cold coolant should have settled to the bottom and the warm (old and green) coolant all flowed out the bleed hole. Hopefully, I now have mostly fresh coolant. Now, leave the bleed screw off, put rad cap on and start motor. Stand back and watch volcano like action as air/coolant spray out the bleed hole. After this stops, remove rad cap, top up and install bleed screw. Drive till upper rad hose gets hot. You probably won't have heat - I didn't. Leave car running - and have fresh coolant ready to pour. Now using a rag or your wife's oven mitts, remove the rad cap. There should be a blast of air that sprays out that's now found it's way to the rad. Remove bleed screw again, and start pouring fresh coolant into rad. When coolant sprays out bleed hole, install screw, install cap, drive again etc. I did this procedure twice before I got 'real' heat, and now my heat is furnace like - much more than before I flushed the system. When I replaced upper rad hose in the fall and air got in the system, I just topped it up and never tried the above bleeding method.

 

I fixed the heat somewhat. I found one of the steepest hills in cincinnati and parked facing up the hill. I then bled the air bubbles out as much as I could. I think i'll get more air out next time it's warmer. The engine really wasn't that warm even with 35 minutes of idling at 1,500. I think this will help a little bit more but i wonder about the valve thingy on the hoses going to the heater core. Has anyone replaced this thing? Could that be some of the cause?

 

How did you do it? Did you just parked the car up on the hill with the radiator cap taken off and have the engine running?

 

I know this sounds really stupid but what about disconnecting the radiator overflow pipe to the overflow tank. And then hold up the opposite end up high, have it held by a stick or something that you could fabricate. THen have the engine kept on running. Would that works for the bleeding procedures?

 

i "think" the radiator cap also acts as a small thermostat. it opens and allows hot coolant to escape into the overflow tank if coolant gets really really hot...otherwise it doesnt allow free coolant flow OUT of the radiator...only sucks coolant in if level is low. this is just theory.

 

Is it a wurbling sound?

 

When the coolant heats up, it expands. Without a rad cap, the coolant would just overflow. However, the rad cap allows the system to become pressurized. By raising the pressure of the cooling system, you can actually increase the temperature at which the coolant will boil. Look at your rad cap and you will see a pressure rating stamped on it. The rad cap is more of a two way valve. When the coolant expands, the cap lets the expanding coolant 'escape' into the overflow bottle yet it maintains the system pressure the cap is rated for. If it didn't the system would build up too much pressure and you would blow hoses (and maybe gaskets?). When the system begins to cool, the coolant contracts, the pressure is reduced and the rad cap now works in reverse and sucks the coolant that had overflown into the bottle back into the rad. Clear as mud?

 

That sounds happend to me every day when I owned a third gen. and my three other friends that had third gens to. I alway's thought it had something to do with the t stat holding and warming up the water. But my third gen heated awsome though

 

mmhmmm....