A little while back a JDM motor got dropped into my Classic. Now the thermostat in the gauge cluster only comes on when it gets really hot. When the thermostat gets about half way across (or high noon) the fans kick on. The car runs fine and doesn't overheat. The normal operating temp. on the gauge now is somewhere on or right above C. I just wanted to fix this because it's a bother to me. :D I don't think that my thermostat got replaced by the people that installed the engine. They didn't really specialize in Nissan's. So does my thermostat need to be replaced with a USDM one? If I was unclear or you have any questions let me know. Thanks.

Find out if they swapped your JDM temperature sender with your old USDM unit. If not, it will give you wacky readings like you are describing.

But, if you do in fact have a dead t-stat, one can be bought for around 10 bucks and its a breeze to install.

DUH! I didn't even think of the sending unit. Boy I need to go and eat breakfast. I don't think they did because everything was working fine before the install. And I don't think that the t-stat is dead. If it was wouldn't the fans not kick on and my gauge not give a reading? How can I find out if I have a USDM or JDM sending unit and t-stat? Thanks.

Originally posted by Peanuthead
A little while back a JDM motor got dropped into my Classic. Now the thermostat in the gauge cluster only comes on when it gets really hot. When the thermostat gets about half way across (or high noon) the fans kick on. The car runs fine and doesn't overheat. The normal operating temp. on the gauge now is somewhere on or right above C. I just wanted to fix this because it's a bother to me. :D I don't think that my thermostat got replaced by the people that installed the engine. They didn't really specialize in Nissan's. So does my thermostat need to be replaced with a USDM one? If I was unclear or you have any questions let me know. Thanks.

I remember reading a post by Rob Cadle (I think) on se-r.net regarding a JDM engine swap. I believe he recommended replacing the thermostat of a JDM engine as well. You could double-check the archives there to be sure.

Steve

Originally posted by NismoSER
Find out if they swapped your JDM temperature sender with your old USDM unit. If not, it will give you wacky readings like you are describing.

But, if you do in fact have a dead t-stat, one can be bought for around 10 bucks and its a breeze to install.

sorry to bring it back up, but where can I find the Temp sensor? I am about to start reinstalling a new engine, and want to make sure i get to it....

thanks
Neeraj

There are two right above the oil filter. They are red and blue, one is the temp sender, and i think the other is the oil pressure sender? Someone else can verify this for sure. Either way, you need to swap both of them.

Why would the oil sending unit have to be replaced? I think mine may not have been done. If I am going to change one sensor I might as well change the other.

is there a difference between the JDM Thermostat and the USDM thermostat? do I need to swap mine out with the USDM one?

Neeraj

I don't believe you need to swap the tstat. The swap that wolfcri and I did did NOT involve swapping the thermostat, and there have been no ill effects yet.