Author Topic: Simple question on a thermostat (Read 3181 times)

jpd · « **Reply #20 on:** June 05, 2005, 04:45:50 pm »

Back to the original thread, I am also very curious about what Barrie would say...

nissparts · « **Reply #21 on:** June 06, 2005, 11:14:35 am »

First thing is to confirm the problem; is the vehicle overheating or is it
just the guage readings being inaccurate.
Is the fan coming on? Not the A/C which you have been using but the main
one. It should enguage at apx 212 C; if not start there.
Poss issues are fan, fan relay,faulty temp sensor.
Other considerations would be to change the coolant and t-stat if you like
but this is more of a maint item depending on how long it has been since you
last did this. Coolant due every 48,000km; t-stat on a as needed
basis;however if you have over 100,000km on it not a bad idea. I would
suggest though that we start by confirming what is causing the problem. The
dealer or a private shop can scan the ECU for live data and fault codes to
help determine what is happening so start there.
Head gasket failure is very rare on the QG18DE engine so not likely this is
the case here.
Best of luck!
-Walter

(Tried your email but Telus kicked it back)

superbaldguy · « **Reply #22 on:** June 06, 2005, 05:15:06 pm »

Thanks. I have a garage checking it on Thursday. I hope a simple coolant change and stat replacment is all it takes. The fan does come on, whether the A/C is running or not.

Wouldn't a faulty sensor cause a warning light to come on?

nissparts · « **Reply #23 on:** June 06, 2005, 10:09:21 pm »

A sensor fault will not always occour.
OBD II sensors report as faults to the ecm but not all sensors are direct inputs as such and may not effect the actual emissions and as such do not trigger the chk eng lite.
They simply provide data to the ecm to assist in powertrain management in that way they are somewhat passive.
For example the guage temp sensor is not a direct input but the engine temp sensor is since it would effect how the engine runs and may cause excess emissions.
The A/c fan is separate from the engine fan so make sure you are checking the right one.
Don't do the other stuff until you determine the fault first...like I said the cooolant and t-stat may only be a maint item here and won't fix your real problem.

superbaldguy · « **Reply #24 on:** June 07, 2005, 05:46:38 am »

Thanks. Hopefully, that will do the trick. If it is a sensor issue, I am goung to unload this car as its electronics are a nightmare and even more disasters await.

nissparts · « **Reply #25 on:** June 07, 2005, 12:33:55 pm »

The electronics are common to all vehicles.
They all have the same basic design since they all have to conform to the same OBD II rules.

superbaldguy · « **Reply #26 on:** June 09, 2005, 05:25:54 pm »

Well, I had a local garage (not a Nissan dealer, but former Nissan techs) check the thermostat - it had started to crack. They flushd the coolant but had to replace it with the old stuff since they could not find a new thermostat, anywhere! Weird. Anyway, I will be getting it replaced, just to be safe

jpd · « **Reply #27 on:** June 09, 2005, 07:24:36 pm »

Good to see that it is very minor problem!

superbaldguy · « **Reply #28 on:** June 10, 2005, 02:46:34 pm »

Yeah. I was *happy* when they attached the scanner and couldn't find and electrical issues. I deserve a break........

barrie1 · « **Reply #29 on:** June 10, 2005, 03:03:17 pm »

The vehicle is 4 years old now so this is the time to do this type of maintenance service on your vehicle. Glad its only a quick service issue which shouldn't cost that much.

superbaldguy · « **Reply #30 on:** June 19, 2005, 06:26:57 pm »

Well, this has come to a happy conclusion - I had the stat replaced, new coolant, all is fine. This was a relatively minor thing, afterall, not too expensive.

I deserve a break=)