Nissan Repair: 2005 Sentra no coolant circulation, nissan sentra, 2005 nissan sentra

Question
QUESTION: hello.  I saw your answer to this question and I have EXACTLY the same situation/symptons.  Did the other person find a bad water pump?  I've never heard of a waterpump shearing off the shaft but I suppose it is possible even though very rare.  My car has been fine except for one morning no heat, fluctuation in temp gauge and now the the symptoms.  Here is  the other guys question from 2008:          

My 2005 Nissan Sentra 1.8s with 55,000 mi. blows cold air from the heater. Coolant not circulating in engine. Lower hose stays cool to touch. Both heater hoses cold. Changed thermostat - didn't fix it. Coolant not leaking or dirty. None in oil - no oil in radiator. Changed worn water pump belt - pump spins freely with no noise or resistance. Cooling fans come on after warm-up. Temperature gauge stays in normal range then jumps to hot and back again. Coolant good to 10 below - didn't freeze here yet. No other problems or repairs to car. Afraid to drive and make worse. Help!

ANSWER: Hi David -

If your water pump was not working, the car would overheat pretty bad in just a few minutes. If the only issue is the heater air not getting warm, I would check the heater control valve. Either it is stuck closed (in which case, replace the valve), or there is no vacuum going to the valve (perhaps a broken hose or source issue).

Hope this helps
aloha
calvin

---------- FOLLOW-UP ----------

QUESTION: Thanks for the reply.   Guess I need to be more specific.  I'm pretty sure that there is no circulation through the engine.  I've replace the t-stat and like the other guy, the upper hose get quite hot while the lower hose never does even get warm.  I've even tested this situation with no t stat in place.  Same thing.  The only failure I've ever seen in a water pump is seal and/or bearing.  I am hesitant to pull this water pump since it is pretty involved even though it appears to be failing to move coolant.  I am not driving the car since I am pretty positive it would get overheated in a few miles.

ANSWER: HI David -

Start the engine and let it idles for a few minutes, watching the temp with the thermostat out. Remove the radiator cap to see if there is circulation. There should be movement in the coolant when you look in the neck. If there is no circulation, there is a good chance that the pump has failed.

I have repaired a couple cars in the past where the impeller separated from the shaft, so it is not that unlikely. Sometimes you can check the impeller by removing the lower hose and sticking a chopstick or similar into the outlet.

Hope this helps -
let me know what happens
aloha
calvin



---------- FOLLOW-UP ----------

QUESTION: Good morning Calvin.  I've done the circulation test already and there is no movement of fluid.  Like the other guy, the upper hose gets hot, pushes fluid out the neck and the lower hose never gets warm.  I shut the car off before it gets overheated.  I guess I was wondering if you ever found out what the other guy's u;timate solution was.  On account of the design of this engine you cannot do the 'chopstick test' on this engine.  I suppose my next diagnostic move is to pull the pump even though it is a big pain on this car.  Most of my other 'surfing' on this problem is that most every one mention 'bad head gasket' problems with this motor.  That may be something to consider but I can't seem to relate that to a 'no circulation' issue.  Thanks again for your interest!!  David

Answer
Hi David -

I never got an answer from that person whether it was the pump or not. I assume it was because I had no further questions from him.

So, I guess the next thing is to remove the pump since all other options are exhausted. I know it is a pain, but it looks like you are on the right path.

Hope this helps -
aloha
calvin