knightsh

2003 auto. Car got hot one day-not sure how hot, but the wife says she could smell it so she came home. I ended up changing thermostat because it seemed to be sticking. Bled air from system and all seems ok but fans run all the time once warmed up. They never cycle. Used scan tool to check temp. Shows temp go up to 213 then fans come on high. Temp rises to 216 and stays. If I rev the engine the temp drops to 210. Checked my parents 02 altima V6. Fans come on at 203 and within a few minutes the temp drops to 185. Then the fans cycle off and temp slowly rises back to 203 and fans come on. Obviously the max doesn't seem right. Leaning towards the waterpump. Asked my local mechanic and he said he's scared to tackle it due to possibly moving the timing. Checked a local import shop and they want $485 to do it. Looked over the write-up on changing the pump, and it doesn't look like a $400 job. Fairly easy or not? I've changed rear valve cover and sparkplugs before, and the thermostat recently. About the same or harder do you think?

DennisMik

iTrader: (2)

The water pump is a more difficult job than the thermostat or spark plugs, but it isn't super nasty. Watch this 3 part series on changing the water pump on a 4th gen which is very similiar to a 5th gen.

Part 1 - http://www.youtube.com/watch?v=ibfs1...ure=plpp_video

Part 2 - http://www.youtube.com/watch?v=GMBIj...ure=plpp_video

Part 3 - http://www.youtube.com/watch?v=1Urfe...ure=plpp_video

Finchum

mine is doing the same thing, but i haven't verified temps yet. I bought the car with a cracked radiator. Changed out the radiator and thermostat and refilled with fresh 50/50 and water wetter additive. As It gets up to temp the fans come on high and stay on. Dash says its nice 2/5's up the gauge. I dont feel any boiling on the driver side hose. there is a decent temp difference on the thermostat neck big enough that I can hold it without pain. So I figured it was circulating fine.

Kinda suspicious of an air pocket, are the vq35de's susceptible to trapped air after a drain and refill of just the radiator? I might try to burp it after work today.

MrEous

iTrader: (11)

I had a trapped air pocket on my old '03 after I changed the radiator. Would get hot quick. Re-did the burping and worked fine after.

foodmanry

iTrader: (15)

Did you check your radiator to see if you are getting flow? They can and have been known to clog. Mine clogged when I exhibited the same type of symptoms as you have.

Radiator replacement is easy and relatively cheap. You should look at this first before the water pump.

knightsh

Not sure of the radiators condition, but previous owner says it was replaced in 2009. When I "burped" it, I left radiator cap off and lots of air bubbles gurgled out. As the temp went up more bubbles came out till mainly just antifreeze was sloshing out. Fans had came on and was blowing it everywhere. Next day I had to rinse everything off to get rid off the smell and slickness. Lower radiator hose feels cool and upper is hot. Used a temp meter on upper hose and it was showing 196 degrees once engine was shut off.
Used the scan tool on the way to work today. Temps reached 216 and would dip down to 210. Once I turned off the car the temp showed 221.
Going to watch the videos tonight and think about it. Can't justify $400 + for the job, but don't want 95 degree weather to get here and it start overheating bad either. Thanks for the info guys!

ShocknAwe

iTrader: (3)

if you have a whole day to do it then go for it yourself. grab a manual, they have a good write up you can keep right there or print out the one on here

Finchum

Thats what I was thinking. thanks for the input, i am gonna do it today after work. I'm thinking the bubble is right on the temp sensor.

02 SE

If that doesn't work....replace the radiator before tackling the water pump. You will thank me later. I did the water pump at 210k and it was a bear of a job. I dropped a bolt into the timing cover and had to remove the whole timing cover to get that bolt out. Bottom line...don't do the water pump if you can avoid it

ImStricken

DUDE ITS YOUR THERMOSTAT!!!!!!!!!!!!
i had the same issue when i changed mine out. once i popped in the original, it worked fine again. i think some thermostats are not really compatible with our cars and cause this.
(i also only changed the thermo, because i popped in a new rad)

fishtale6spd

iTrader: (13)

Or get a nismo thermostat will run even cooler

Galactica

iTrader: (5)

I wonder if the vq motor behaves like my hemi did in that it ran with more power in the 190 degree range over the 200-205 range. Granted that was backed up with not only the jet 180 t-stat but a predator tuner and adjusted low and high speed fan settings

Finchum

Im thinking my NEW autozone thermostat isn't opening...the elbow there is cool and the other side is to hot to touch.....Bout to go back to the original!

i changed it because I needed a new radiator and figured it would be best. Same thing had happened in my old 2000 altima. factory thermo was fine while the new autozone one didn't open like it should.

knightsh

Well, changed the waterpump this weekend. It was obviously leaking, but a new pump didn't fix my problem. Not sure what else to try. Radiator looks fine, previous owner said he replaced it, although it is a Nissan radiator. Not sure if most people would buy a radiator from the dealer. Fins look good, and it's still silver, not all dirty. Air conditioner works fine so air obviously passes across the condenser ok. Ran some radiator flush through it a few weeks ago and when draining for the waterpump replacement I got a full gallon from it where only half the previous time.

Finchum

Alrighty....changed the thermostat back out to the factory. Autozone duralast thermostat sucks. Runs better and shifts smoother....not to mention proper fan functioning

knightsh

I hear you now ImStricken! My thermostat came from O'reilleys and that is the problem. I just pulled the thermostat from the housing and refilled and bled everything and problem is gone. I can see plenty of flow across the radiator. Granted it's slow to heat up, but then it's fine. Using the scanner as before, fans on low at 203 degrees. and temp cools slowly to 190 degrees and they cycle off. I can't believe it! I changed my waterpump for nothing! Well, it was leaking and I had to add water to the reservoir weekly, but still.
Anyone know if a Nissan thermostat will fit aftermarket housing?? The aftermarket one does not bolt in. Just spring tension holds it in. And of course I threw out my factory one!

DjHackStyle

Dude I am going through this same problem, I bought a thermostat from beck arnley it's doing the same thing, I couldn't believe a new t-stat would do this,anybody got a part number for the original? I tried courtesy parts but they show a picture of a diff t-stat for my 03 maxima. How do you do the bleeding of the coolant?

dfj240

iTrader: (1)

Nissan factory part# is 21200-8J10B for the thermostat on the 2002-2003 Maxima. List price is $24.43.

-Nathan

EDIT: That part number also supercedes 21200-8J100.

DjHackStyle

ok guys i fixed my problem!! ImStricken you are a genius!! i had the same problem as the original poster and my fans were constantly on because my temp would not go lower. this was after i replaced my thermostat with a beck arnley one, i purchased from rockauto and for some reason it wasnt working right.
i put a nissan original thermostat and my temperature is now normal, my fans turn on at 203 and my temp goes down to 190 and they shut off, exactly the way its supposed to work!!
for some reason the thermostat at autozone was $49 and thats why i went online and just got it from rockauto. i never thought to check how much it was at the dealer, i figured if its $49 in autozone it must be $100 in the dealer! but totally not true, i got it for $26 and i added the gasket for another $3 so this was about the same price as the thermostat from rockauto with the shipping. lesson learned.