Take a look at the picture below, made up of two shots taken at the same time, one of the dash temp gauge and one showing the ConZult temp reading, a surface reading was also taken using an infra red gun of the top inlet hose where the temp sensors fit and confirmed the ConZult reading of 100degc whilst the dash gauge is sitting happy at normal, the temp sensor was changed with the exact same result, the water was full to the brim too, so be careful, unfortunately too late for now this one is needing some head work as a block test confirmed exhaust gases in the water !!

 

Jeff TT

 

So If the temp sensor was changed is it a prob with the gauge ?

Always good to have an aftermarket guage even with its own sender.

scary stuff

The OEM gauge had three stages, cold normal and overheated.

Any idea what the temp should be with the gauge in that position?

NEVER rely on the factory temperature gauge. They are only reliable for indicating that the engine isn't cold. Anything above, and you're rolling the dice.

 

A TWD (Temperature Warning Device) is a handy installation for those who want to retain the factory look over installed A/M gauges. An LED installed wherever preferred (usually on the face of the OEM temperature gauge) gives an accurate indication, fed via the ECU CTS, as to when an adjustable temperature is reached. Rather simple to make yourself, there's an article on the aus300zx forum. Many of us over here are using them.

z32bolt is right. It's a stepper gauge and only shows Cold, Normal, Hot. I was trying to find the figs in the manual last night but a) while watching Tom Baker in the Planet of Evil and b) a rather nice merlot meant I wasn't concentrating too hard. However the search is on again today. So far I have found this vid which shows exactly what z32bolt said. Translating from deg F into C:

Cold: up to 135 F / 57 C

Normal: 135 F - 217 F / 57 C - 102.7 C

Hot: over 217 F - 102.7C

 

So the 100C means it's still within a range that Nissan considers normal so the needle still points left.

Having said that, using my ECUTalk shows that even at the hottest day of this summer stuck in creeping traffic round NCR/Hanger Lane hell, the hottest I saw was 95/96. If I saw 100 in ordinary conditions, I would be worried.

Here's the vid:

[video=youtube_share;xeCp9l_nG4Y]

same guy also did OEM Oil gauge

[video=youtube_share;wqFco6CFHg8]

Interesting point that it's a direct connection between sender and gauge not going via ECU like just about everything else.

Kudos to jschrauwen whoever he is - he must be right, he's got a silver one :D

 

I just found him - he's a member here last posted in 2009 halllo John, nice vids. He's a Canuck from Franklin, Ontario and knows FunkySi.

Edited September 7, 201411 yr by Gio

OK, haven't found the exact gauge figures yet but here are the ECU figures when it turns on/off the fans so that's a reasonably inference this is what Nissan thinks about engine temps. The behaviour is different Turbo / Non-turbo and whether or not aircon is on or not. And remember the TT has an extra fan (IIRC). My guess is that LOW means just the one fan and HIGH means both but this needs confirming.

 

NA and Turbo is the same when aircon off:

below 104 C / 219 F - fan OFF; above 105 C / 221 F - fan ON

 

If the aircon is on, the fan trigger temp depends on speed (guess to allow for natural airflow through rad)

NA below 24mph: below 94 C / 201 F - fan OFF; above 95 C / 203 F - fan ON

NA above 25mph: below 104 C / 219 F - fan OFF; above 105 C / 221 C - fan ON

 

TT below 24mph: below 89 C / 192 F - fan OFF; between 90 C / 194 F and 99 C / 210 F - fan LOW; above 100 C / 212 F - fan HIGH

TT above 25mph: below 104 C / 219 F - fan OFF; above 105 C / 221 F - fan HIGH

 

From memory, that explains why my NA topped out at 95/6 on f hot days in traffic because at that temp, the fan came on. Normal traffic speeds, normal days around 82 - 84 or so.

Every 90s turbocharged car I've worked with is exactly the same. My old MR2 Turbo could hit 110 deg C whilst the guage sat comfortably in the middle, only beginning to move a tiny amount. As Mr Bolt states: cold, normal, overheated. That's all Joe Public ever needs to know :)

Trouble is though, the general issue is once it starts going north your already done. I've had it happen myself that needle leaves the center line and just heads north. I'm installing 3 gauges and I think personally a proper temp gauge has to be one of those 3 an early warning is incredibly useful.

It was the same on my XJR as well, thinking about it.

A lot of new basic cars simply have two lights a blue to say it's still cold and a red to say your overheating, no gauge at all that's how my mrs car is.

well I was going to go for a discrete little boost gauge now I know I will be looking at another to keep it company :)

There are some multi purpose gauges, that read more than one perameter if your tight on space.