Anyone know how Ohms the Coolant Temp sensor (to ECU) should read. trying to work out if mine is shot at the mo.

 

 

Big thank you. Mine seems to read ok which is strange as I could have sworn it was shot.

Back to the drawing board to find out why my rad fans wont kick in

 

Well if youve gone that deep into checking then im sure youve already checked your fuses fan plugs..I also think i have a malfunctioning coolent temp sensor because my car will get hot when im at a stand still or sometimes it will spike spuratically...my fans work but usually when they come on they stay on.....so my temp sensor shoudl read 2.1-2.9 ohms??

 

A good way to tell if you coolant temp is bad is 1:

Radiator fans come on at the wrong time- example- My fans came on when I just started the car for the day, and it was cold outside. The fans would come on just while driving and make the car seem like its running hot, when its really not. Another sign is when sitting at idle for a while like in traffic, the temp guage starts to go up more and more almost to the hot mark, and guess what? No Fans are on or comming on either! I know this because I replaced my temp sensor with one out the junk yard, and it worked for a week or so. Nothing was wrong with the one that was originally in the car, I just swapped it out just to do it, then the car started acting crazy. To make a long story short, both sensors went out eventually and I went to autozone and got one for like $15 and that solved the probelm

 

Don't forget to add the kilo prefix when measuring it.

Maybe the contacts on the harness is bad? Should try cleaning it. I replaced the temp sensor on my car recently because the fans wouldn't kick in when they started to overheat. But I also noticed that the contacts on the temp sensor had corrosion on it too.

 

Fans work ok. They kick in if I disconnect the CTS. The needle on the temp guage never goes over half way even when I know the car has overheated, so I have a fault there too.

It's not too easy for me to get parts for this car as they are rare in the UK. I called Nissan parts to be told my car does not exist the other day !!!!

 

Did you measure the temp sensor when the car is running warm? Because the bad one I had the resistance would stay in the range where the fans would not kick in at all when it's warm.

 

Did you check to see if there were codes on your ECU?

When my CTS was bad, it actually had a code stored in there for it. No check engine light, though.

You might get someone to buy one for you and have it shipped. They are only about $20 US and they are small so shipping would only be a few dollars. That would be about 14 British pounds with shipping.

 

yah my ecu threw a code when the coolant temp sensor went bad, I think it was a code 13 or something.

 

Fans Def work OK because when I pull the harness off the CTS, the fans kick in. I ran the CTS under hot water and the readings seemed OK.

No codes on the ECU

Maybe I'll just replace it anyhow. Will make a trip to the junk yard during the week and see if I can find another Nissan CTS that will fit.

 

................... and you know its "overheated" how?

 

Beacuse when I have popped the bonnet it's all much hotter than it should be

 

how much "hotter" was it then and how did you determine that? ................. lost-some-skin-off-your-face-by-simply-looking-at-it "hotter" ? ................. or some other degree measured how?

 

Simply to touch. Sometimes after a 5 min drive the plenum is warm. Other times it has been so hot you can not touch it. Yet the guage reads the same. Also the bonnet can become very hot.

 

IMO you are wasting your time chasing a non-existent problem.

Unless you can somehow confirm overheating with eg a infrared thermometer (thermostat housing runs around 85C on a normal 3rd gen in my experience) I don't see any need to spend money on any spares yet and your tests till now basically confirms that too,

FWIW my intake can get as high as 75C on really hot days with town driving near the TB and the actual bits after the TB gets to around 80C+ .................. and its all pretty normal and as expected ......... and my bonnet get to around 50C whn moving - quite a bit higher soon after you stopped and heatsoak starts working

 

Pretty sure my CTS is shot now so going to replace it. Nissan can get me a CTS but want £50 for it ($77 !!!!)

If need be i'll have to try and get one over from the states but ideally need the car running ASAP.

Anyone know if there are any other Nissan engines I can get a CTS out of that will work? They have quite a few ALMERA's down the scrap yard but not had a propper chance to look yet.

Same question with injector o-rings. They are £10 each ($15.50 !!!!)

 

What other nissans do you have over there?
I don't have experience with too many of the engine internals, but the best way would be to simply pull the FSM and look in each FSM for the correct resistance range between cold & hot. then head to the dealer (or scrap yard) for the sensor.

USUALLY Nissan will use the same sensors across several model lines, as well as the injector o-rings since they use the injectors on many cars.

What engine(s) are in the Almera? Anything with a VG or KA engine in it from roughly the same age range as your Maxima?

Edit.. all that said, I'll be glad to ship you some parts from the states if you need me to. I've done "exportation services" for a few other people in the past.