mwilhelm

my 99 SE has 124k , just replaced both cv axels, it overheats while idling. I replaced the thermostat. The dealer said it was the fans. both of them at just under $200 ea. I said I'll wait, took it home and both of them kicked on. As long as I'm going down the road it is fine. anyone have any ideas? Also the A/c doesn't seem to want to kick on while it is idling also.

njmodi

iTrader: (4)

Does it overheat if the AC is off?
You can pick up a replacement fan tray for much cheaper than 200 bucks, check rockauto.com, Ebay, etc.

njmaxseltd

iTrader: (19)

It does soumd like an intermittant fan issue, being the a/c isn't working at idle speeds (standing still) either.

mwilhelm

if the a/c is off it still will overheat. I checked the fuses and relays, they all seemed good.

PAREDLINE

Your fans run on two speeds. Two separate relays and circuits. They run on slow and fast. If your fans run on slow all the time you might think they work but they dont run on fast, they just shut off.

There's a good cooling fan diagnostic for this in the nissan service manual. Maybe you can get it in a library or something.

PAREDLINE

Another thing you want to do is let the car heat up. Then let the fans go on and feel if the air coming out of the fans is cooler. If the air blowing is pretty damn hot then your radiator isnt cooling effectively. If the fans check out and there's no air in the system, you should remove and back flush the radiator. stick a hose in the bottom hole of the radiator and let the old coolant come out the top until the water is clear.

Crap i keep forgetting things. You should also do this back flush for the heater core. Remove the thermostat. Set the heat on with the engine on ignition but not 'on'. put the hose in the hole where the thermostat is and let the water come out of wherever it does. I think it should come out of the bottom radiator hose. Wait till its clear.

When you refill the coolant make sure you run the car with the radiator cap off so the air is bleeded from the system. If you still have problems then take the belts off. Feel if the water pump turns and feel if it turns too freely or if there's a little resistance. If it turns too freely the fins may have separated from the shaft in the water pump. I have NEVER seen this happen but people always say to watch for this.

Another thing is your heater core might be clogged. The tolerances through the heater core are much smaller than the radiator. The radiator might be clogged as well. Especially if you feel the air coming out of it and half of it is cool while the other half is hot. The hot half is clogged.

Overheating problems are a pain in the bung. Dont overlook the simple things.

Akumachan

iTrader: (12)

My car was overheating at idle for a while, tunred ou the radiator was low, I had never looked at it, I just always looked at the reserve, but I guess that means nothing. Anyways, just a thought.

mwilhelm

thanks for the help. I let it heat up again and the fans didn't move. I just touched one of them and it took off. It's a pretty good indication the fans are wearing out.

PAREDLINE

Dude dont change the fans. Sounds like you have a bad connection somewhere. This happened to me too. Check the harness. Make sure the little rubber seals around the wires in the fan harness are inside their holes. You'll know what i'm talking about.

I had a bad connection so what I did is make sure it was in contact then i put a bunch of zip ties around the entire harness so it wouldnt move.

If I had a scanner I'd send you the fan section of the nissan service manual. Maybe someone on the forum has it in .pdf format.