1. My cousin said her car ('00) overheats (in warmer weather, not in the cold) in heavy traffic and when idleing. (The needle goes up over the halfway mark). But when she starts moving the needle goes back down to the halfway point. She told me the fans turn on after the car has warmed up.
2. The traction light is on and she said something smells like burning? wtf?

What to do next?

Thanks

sounds like a fan problem

1. Someone's got a radiator leak?

2. No more burnouts!

I agree, sounds like a fan problem. One of my fans used to be loud & cause a lot of vibration. I disconnected the electrical connector to one of the two fans so that only one of 'em comes on. This was fine & I didn't have any overheating problems when the temp outside was under 70ish.

On warm days (>70 degrees), in stop & go traffic, the needle would rise almost to the top. Once I reconnected the other fan, the needle never went higher than center on cold or warm days. Nominally it's a little bit under center.

So make sure that both fans are coming on. There's two speeds also. Check the condition of the blades too. Make sure your radiator's full & air is bled out if you do a drain/fill.

Fan problem. /thread

Summer is close, here come the overheating and AC threads.

It could be many things. Radiator cap, thermostat, radiator, cooling fans, air in system, low coolant, wrong mix of coolant, water pump, ???. When I had the same issue it turned out to be a partially clogged radiator. It had flow, just not enough. I changed the radiator and no more overheating. But as stated by others, check the fans first. Also make sure its full and bled of air and the reservoir is at the correct level.

As for the traction light and burning, good luck.

I had the same thing one time after changing the thermostat. I had gotten a cheap one from autozone and it wasnt opening right. Replaced with an OEM thermostat (only $1-2 more) and the problem went away.

But like Reizy said it could be any of those things. Start with the easy and inexpensive stuff. Check if the fans are operating properly, do a coolant flush, then start looking at the other options.

I got the car yesterday. Today I went for a 20 min drive and the temp(according to the guage cluster) did not move at all, not even one time, while I was driving around. Neither did it budge at red lights and longer stops. Then I came home, left it on Park, and turned on the AC full blast. Sure enough the temp started moving upwards... both fans were on...wtf? Coolant levels are topped off. What to check next?

whens the last time the fluid was changed? maybe there is an air pocket? take it to a gas station have them pressure test the system as well.

check for debris on condenser and also check for leaves in between condenser and radiator. get a hose perhaps low pressure power washer and clean it.

One more thing

The fans seem to be operating correctly because as soon as I started the car, I turned on the AC to check if the fans turn on. sure enough they started right up.

I was running the car at idle with the ac on full blast and the temp did not move.(car was started first time since last night)

later I took it for a drive and refer to post #8.

I will double check it now. thanks for the tip

The area between the rad and condensor is clear of any debris...

Either your thermostat (unlikely) or clogged/blocked radiator. Seems to be a fairly common problem with 5th gens.

This is something you can easily change yourself and should be able to get an aftermarket Koyo radiator for a little over a $100.

Change the thermostat first to see if it has an affect. Try flushing the system and just refill with distilled water. If its still overheating while sitting in park you have a clogged radiator. If it doesn't overheat you can drain some of the water out and refill the balance with coolant for the right mixture you need.

Had the same problem with mine last year. I drained and took out the radiator and sprayed the fins out with a pressure washer and mosquitoes and leaves came out for literally 10 minutes. It worked great and I'm most likely going to do it again when I flush my radiator next week

Well said.

DEF a fan issue

I cleaned out the radiator today, and it was definately nasty. I will give the car back to my cousin to drive around and see if the problem is fixed. If not, the next thing I will do is the coolant temp sensor.

looking at a similar problem but a few more details, Let's begin..... start the car, turn the a/c on and . . . . no fans. ok checked all connections, fuses, and relays, all good so i put 12v from the battery to the fan itself, once again no fan. normaly at this point i would say replace it and move on but it seems weird to me that but fans would stop working simultaneously. anyone out there a little more fimilar with the electrical systems for these fans? do i need to run a seprate ground as well as the 12v from the battery to the fans. Thanks

These are classic symptoms of a clogged radiator (unpredictable behavior, overheats one time and them all of a sudden it goes away).!!!

To check if you have one, drain the radiator, all the coolant should flow in one shot, a large gush followed by trickles. If the radiator drains slowly, get a new one.

New radiators are cheap and solve most of the problems! I replaced mine and it solved my heating problem.!!!

Love_00_Max, what if when you drain, you get a large gush, but then "spurts" (for lack of a better analogy, like the "milk" flow when someone milks a cow...)?

I initially had fan issues leading to overheating when moving slowly (if outside temp was over 70) and and when I replaced the fans, it didn't overheat.

Now that summer is here and the outside temp is over 80, I overheat if I'm not moving.

Could someone explain how the coolant should flow in a functioning system? I always thought that the coolant level in the reservoir should get low when it gets hot (meaning the coolant is flowing throughout) but it seems my coolant level in the reservoir is pretty constant.

Yeah, u should get a large amout of the coolant in the radiator out in no time, less that a minute, then slowly the remaining drains. Capacity of radiator is 4Q, you should all of it out in no time followed trickles.!!!

A clogged radiator will flow fast, slow down, flow, slow, flow and it will be quite obvious.

Change the radiator cap ASAP.

If you dont suspect a raditor, put the coolant back into the radiator.

Not a fan problem. I'm assuming it happens when the AC is on quicker than when it's off. I had the same problem last August and made a thread about it

My friend and I drained the coolant and took out the radiator and sprayed the fins at a self server car wash and bugs and leaves and **** came out for nearly 10 minutes straight. It went from barely seeing through the fins to seeing clearly through all of them. After we put it back in and filled it back in and got all the air out it hasn't overheated since

The reservoir is a holding tank for the thermal expansion of the coolant. Everything expands and contracts with temperature, including liquids. The cooling system of an engine is always full of coolant. When the engine heats up, the coolant expands and the excess goes into the reservoir. When you turn off the engine, it cools and the coolant in the engine contracts and creates a vacuum which sucks what it needs from the reservior to re-fill the radiator. The reservoir is not an active part of the engine cooling and is not how you fill the engine with coolant.

My old 4th gen did the same. I have a radiator leak. It was cracked :/ but radiator isnt a big job.

i have like no money for car repairs so i try to avoid idling as much as possible. since i do 70% highway driving, it's never really a problem cuz once you start driving 35+ mph the engine cools back down in like 30 seconds.

The AC does get hot once you get stuck in traffic jams though, and that's annoying.

Maybe there's a prob with the fan...

But sooner or later. Its gonna get worse. its only not that bad because its fresh and not a big problem. but will lead to a bigger one.

Thanks for that explanation. I assumed differently (maybe 'cause my old car was a GM/Chevrolet), but once it reached operating temp, all coolant in the reservoir would literally disappear....and of course reappear after a 10hr resting period.

Would it be safe to do this with the rad still in the car? ...and then driving away 10 minutes later?

actually the problem has probably always been here but is only noticeable because of the heat. if its just a fan problem (which i suspect it is) then its no big deal ill just ignore it for now

Is there a thermostatic fan switch on a 97 SE? My Maxima is heating up at idle and in heavy traffic with the a/c on and off, but the fans don't come on. It seems unlikely that both fans would go out at the same time. Normal driving seems to allow enough flow for it to cool back down quickly.

if the fans r fine check the thermostat thats always an easy n quick fix. after that flush out system n refill radiator.

Absolutely check that there are no air bubbles in the system.

I have a 2k, and had those similar problems last summer. I just went ahead and changed out thermostat, and radiator, since it was all original and probably going to crap out soon anyway. Problem solved! And one of my fans still dont work, but i never got around to changing that yet. a year later, still no problems...

It could be unlikely that both fans die at the same time, but it is also possible that you didn't notice when the first one went out. There is a way to check if the fans are at fault or if the problem is caused by the relays that control them, by either checking for power at the fan connectors and/or directly powering the fans. I don't have the specifics right now but I know a search would yield some useful results. There is also a troubleshooting procedure in the FSM.
A lot of times it's more cost-effective to buy the whole fan assembly rather than buying fan motors. (After searching from different vendors, local and online, I got mine from Amazon). Take care of that problem soon before it becomes something worse. (...and hopefully we won't get flamed for reviving a year-old thread).

I have a 2001 I30...just recently started to overheat since the weather is getting hot..the needle would rise all the way up almost 90% mostly in stop and go traffic or wheni have the AC on...the fans seem to be working and i just changed the thermostat and that didnt help...anyone knows what else i can do to fix this problem...

Not sure what you you mean by "the fans seem to be working". You need to make sure whether they are working or not. It is one of the first things you need to check.
Also, read through this entire thread; there are a lot information that you might find useful.

I had this same problem a few weeks ago. It turned out my radiator had a crack in the upper seals. At first there was no signs of a leak (so I didn't suspect the radiator), but the car would still overheat in stop and go traffic and when I had the A/C on. A few weeks went by and coolant was spraying all over my engine bay. I've changed the radiator with a replacement from the Koyo group deal and it's been working great for the past two weeks.

had the same problem with my 2000 auto and it was the fan one comes on when the car heats up but the other one the A/C fan was out changed the fans problem went away....