[KeithD1]

I have an amazing 2004 that just clocked 200k miles! Unfortunately, it is now overheating and heater only blows air temp.

Today, I tried burping the coolant system hoping that was the problem...~20min at idle adding coolant as necessary...coolant remained at 220f at idle but spiked to 240f within a short block of driving under load. There was no apparent leaking but I was able to add ~1/2 gallon of coolant after parking.

I suspect the water pump has failed but would love a second opinion or thoughts about what else I might try. Thank you!

 

[MuranoSL2003]

It sounds like you may still have an air pocket in the heater core, this in common when replacing the coolant. Did the problem develop after performing a cooling system service, or did it just occur on its own?

Using a device like this will help bleed the air out of the cooling system. It raises the water level in the funnel above the engine's cooling system to more effectively burp the cooling system, air will seek the higher level:

https://www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY/ref=sr_1_1?crid=1EALM7W9YOE7M&dchild=1&keywords=lisle+funnel&qid=1613035593&sprefix=lisle+fu,aps,153&sr=8-1

 

[I need coffee]

Before bleeding the cooling system, pressure test it to confirm whether or not there's a leak. You can usually rent a kit from your local auto parts store if you don't have one.

 

[MuranoSL2003]

Also pressure test or replace your radiator cap, especially if it may be the original '04 cap... The radiator cap needs seal the system enough to raise the pressure in your cooling system. This will raise the boiling point of your coolant to prevent overheating and displacing some of the coolant with air.

 

[KeithD1]

Thank you all! I did flush the coolant about two months ago and ALL was well until just recently.

I pick up the radiator and cap test kit from O'Reilly tomorrow afternoon (I love tool rental programs!). I'll report back the results and then proceed with the Lisle tool proper burping of the system. Fun!

 

[KeithD1]

I couldn't wait and got the pressure tester today...and found out I have a cracked upper tank on the radiator!

I worry that is a symptom of my recent near-overheating so will continue to diagnose a little bit, but it is clear that it wouldn't work in that condition. Thanks!

 

[MuranoSL2003]

Thank you for your update!

 

[I need coffee]

I couldn't wait and got the pressure tester today...and found out I have a cracked upper tank on the radiator!

I worry that is a symptom of my recent near-overheating so will continue to diagnose a little bit, but it is clear that it wouldn't work in that condition. Thanks!

If it's the original radiator, then it's not a surprise that it would fail after 17 years. The plastic that auto makers started incorporating into radiators to save money has become the common failure point. Years of thermal cycling causes the plastic to become weak and brittle and eventually a crack opens up since the cooling system is under pressure.

Replace the the radiator and the hoses (if not replaced before), bleed the cooling system with the tool MuranoSL2003 recommended, and then pressure test again to make sure the system is now sealed. Good luck!

 

[DrDurst]

You might want to test for exhaust gases in your coolant as well, and diagnose a possible blown head gasket [which could happen from overheating] you can rent these at auto parts stores.

 

[markayash]

I couldn't wait and got the pressure tester today...and found out I have a cracked upper tank on the radiator!

I worry that is a symptom of my recent near-overheating so will continue to diagnose a little bit, but it is clear that it wouldn't work in that condition. Thanks!

I am about to replace mine, got one from Walmart online for $70 and looks fairly simple to swap..I have a separate thread..Mine is a 2007 but should be similar

 

[KeithD1]

Update: I used JB RadiatorWeld to seal the crack in the upper tank. Heater worked and the car maintained appropriate operating temperature for a 30min test under load. Later, when I went to burp the coolant...I noticed a new leak from the top of the radiator (at the upper tank seal) when the system wasn't pressurized. Later again, the new leak wasn't at all leaking while the car was in operation but the JBWeld seal of the original leak failed. I have a new radiator and hoses arriving on Friday! Markayash and I have our weekend plans!

 

[markayash]

radiator repalcement 2007 FWD

I think my radiator needs replacing. Been trying to find the leak, its always a quart or less low but learning it leaking at the top so leaks when full but not after the level drops. I am looking on line and seeing several for $70..Also watched a youtube video and looks fairly simple. Has...

www.nissanmurano.org

 

[markayash]

radiator repalcement 2007 FWD

I think my radiator needs replacing. Been trying to find the leak, its always a quart or less low but learning it leaking at the top so leaks when full but not after the level drops. I am looking on line and seeing several for $70..Also watched a youtube video and looks fairly simple. Has...

www.nissanmurano.org

Report
Cryogenix1 posted it.

 

[DrDurst]

Report
Cryogenix1 posted it.

Cheap [chinese] radiators are weak and can fail unexpectedly, I put one in my 321i and resulted in a blown head gasket [I had to sell the car]. Get a quality brand, you won't regret it.

 

[KeithD1]

Update: New radiator is in and Murray seems to run fine. I've idle'd for 30min (twice) and taking several 1mile runs up the local hill (coast down if something goes awry). Torque Pro shows the engine coolant temp pretty stead at ~180-186f. I'll continue testing and report back any significant updates. Thanks again for the all the advice.

 

[markayash]

any issues getting it in? I am on call for work and my wife is out of town so waiting before I tear it apart just in case I break something and need a part.

 

[KeithD1]

any issues getting it in? I am on call for work and my wife is out of town so waiting before I tear it apart just in case I break something and need a part.

It wasn't too bad. I did it single-handed in about 90min. Going step by step through the service manual instructions made it easy. I didn't remove the reservoir but removing the battery and tray was necessary. It was a tight fit so working with two would have been nice. Have fun!