Dasyce

iTrader: (3)

At the end of last summer I decided it was time for a radiator flush, I made the horrible mistake of using Prestone Flush. And I flush the system with water / flush mix. It initially seamed to have good results. And driving around all winter, it seamed fine.

Anyway, driving about 15min on the highway ~70-75 with A/C on. I noticed my temp needle went 3/4 up. I immediately turned the A/C off and coasted till I got off the highway. ( could hear a water bubbling noise) so I popped the hood to see that my radiator reservoir was bubbling out coolant. I let the car cool off for about 4 hours. I had to go home, so I topped the reservoir off with Poland spring, 2 large bottles (not gallon) and drove home with A/C off. I got home and the reservoir was again bubbling out of the overflow.

Basically it overheats bad when the Ac is on, but its still overheating without the A/C off.

I’m suspecting its either: trapped air bubbles in the radiator, coolant thermostat gone bad, bad mixture of coolant to water ratio,

Just wanted to see if anyone else could shed some light on this.

PS. Thanks in Advance.

njmodi

iTrader: (4)

Bump for you. The thermostat is easy to pull/check/replace and cheap. I don't know if it is your thermostat though, since they are designed to fail open (so you run cool) rather than closed (where you would overheat). I would lean towards the water pump - sounds like the coolant isn't being circulated through the system.

Dasyce

iTrader: (3)

water pump, the car only has 70K miles on it, and i drive slow..

njmodi

iTrader: (4)

So it was the water-pump?

Mishmosh

iTrader: (3)

Doesn't make sense that it would be the water pump. I would guess clogged radiator or faulty thermostat.

Nismo3112

iTrader: (12)

I vote for the air in the system.

Did you let the car run with the cap off?

Dasyce

iTrader: (3)

i bought a new theremostat from Nissan, i'm gonna get some coolant from toyota (red) and some distilled water from pathmark.. i'll let you know how it turns out. i don't think its the water pump. but i let you know.

Thanks for the responses, i appreciate them all

Dasyce

iTrader: (3)

So, as said earlier i have come back with my experiences.

With much frustration I had purchased a new Nissan Thermostat, I also drop by Toyota red coolant. I first started to drain the coolant, then I took out the old thermostat, and replaced with the new one. I then proceeded with the full flush with only distilled water. (in my experience the flush soap is a bad thing for the longevity of our radiators.)

To my surprise there was a lot of white crystallized substances in my coolant. 6 drains later that was minimized. I refilled and went for a spin, I turned the AC on I got about 2 miles and the car was again overheating. I turn the AC off and drove back home. I decided to take the advice of NISMO3112 and run the car for 45-50 mins with the radiator cap off.

I also let the car in code43. I say a few bubbles appear but not many. I decided that I would go out for another spin. I turned the AC on again. I expected the temperature to go up. But nothing, I picked a friend up, and kept going, drove for about 2 hours. And the car was finally run strong again.

Thanks NISMO3112, looks like you were right, there were air bubbles trapped in the radiator that were causing the problem. The free easy fix did the trick.

joecraps

While you are at it change the rad cap - Stants are about $ 10. Those wear out and will cause the overflow tank to exhibit exactly what you described.