First start on fresh rebuild (overheated) :(

[brynden29]

I had some problems getting it to idle after my rebuild, but I found a huge vaccum leak at the TB and that seems to have fixed it pretty good, it still surges a little, but that is the least of my concerns right now.

After I got it idling pretty good I took it around the block. I got back home and noticed my coolant temp was pretty high, reading 245 on ECMlink. I got a check engine light (I assume because of the high temp) and I see smoke under the hood. Coolant is shooting out of a hose (again I assume because of the temp). All this time my radiator fan is not on.

I installed mishimoto slim line fans and spliced into one of the wires I thought would have power for the radiator fan, but I guess not. The A/C fan turns on when I turn it on. Is there a way to turn the radiator fan on just so I can make sure it works? I checked the radiator fan relay and there was power on two of the pins but there is no power at any of the wires for the fan. Are there more radiator fan wires down below? It is really odd.

Other than that, the car seems alright, it is still not completely right, but I will not be building any boost for a while anyway (new bottom end and new clutch) so I can put up with the rough idle.

The overheating thing is not good. Any help you can give would be greatly appreciated.

How do I make sure I installed the thermostat right?

 

[redyute1]

With the ignition on unplug the thermo switch located at the bottom of the radiator next to the lower hose,its a white two pin connector.Get a piece of wire and jump the connector pins,if the fan is connected correctly the rad fan should turn on,if it doesn't then your connection is wrong. Another thing when you do get it to turn on make sure its pulling and not pushing.

 

[brynden29]

Thanks.


I actually realized that I do not have the thermosensor installed. I threw it away with my old radiator.

I will get a new sensor and I am sure that will fix it. Thanks!

 

[redyute1]

You got it bud

 

[undesiredshoe]

Did you even bleed it? Your fans should never turn on if you are moving 10+ mph...there is enough air flow going past the radiator. You wont overheat while moving if your system is properly bled.

 

[Calan]

You wont overheat while moving if your system is properly bled.

You do know he's driving a DSM...right?

Check out this article in the tech section, or just search on "overheating".

These cars are notorious for running hot and overheating, especially if they have mods done to them...and there is a lot of information on this site about where to start as far as troubleshooting the problem.

 

[undesiredshoe]

You do know he's driving a DSM...right?

Check out this article in the tech section, or just search on "overheating".

These cars are notorious for running hot and overheating, especially if they have mods done to them...and there is a lot of information on this site about where to start as far as troubleshooting the problem.

Lol Im new to dsm's, I come from the world of Nissans, where everything works perfectly according to the laws of physics

 

[donniekak]

Lol Im new to dsm's, I come from the world of Nissans, where everything works perfectly according to the laws of physics

Physics works perfectly here. For one thing our radiators have a very small size for the amount of power a lot of us make, and second i have a big fmic, and a ac condenser in front of my rad. I have to be going over 45mph before i can turn my fans off. It doesn't help that my ambient temps 2 ft off the road can be 130*+.

 

[brynden29]

So I went and looked and I can not find the thermosensor connector on my car. I am pretty sure I didn't cut it off. Can anyone tell me where it should be? I hope it was not connected to my fan (which I threw away). Thanks!

 

[brynden29]

So I know the connector is gone. How can I hard wire this to work? There are 2 connectors on the thermosensor, does anyone know how I can wire it to make it work?

 

[brynden29]

I just wired the green wire with a black stripe to ground for now. The fan runs all the time, but since I am I Texas, that is not a bad thing.

 

[undesiredshoe]

Physics works perfectly here. For one thing our radiators have a very small size for the amount of power a lot of us make, and second i have a big fmic, and a ac condenser in front of my rad. I have to be going over 45mph before i can turn my fans off. It doesn't help that my ambient temps 2 ft off the road can be 130*+.

You think dsm radiators are small, look at a stock 240sx's radiator, its probably .5" thick. I also have a 2.5" front mount and the bottom of my radiator is like 2" off the ground. Im also making 280-290hp on a stock "truck" motor. I guess my nissan is the one defying the laws

But you live in arizona so its different but back on topic....your fans were designed to be on constantly and if you are still overheating at high speeds with the fans off, then you still have a problem.

 

[brynden29]

Can someone tell me what color the wires are that go into the thermosensor?

 

[viprez586]

Did you even bleed it? Your fans should never turn on if you are moving 10+ mph...there is enough air flow going past the radiator. You wont overheat while moving if your system is properly bled.

You need to be traveling at least 35mph to provide efficient flow to the radiator. Anything higher then those speeds the fans create turbulence and become a restriction if turned on.

Most definitely you can overheat while moving - this is a possibility on all cars.

 

[viprez586]

Can someone tell me what color the wires are that go into the thermosensor?

It's Green with a black trace, and a black wire. Should be located on the passenger side.

I simply ran a switch to the connector and watch my temps on my logger so I can control my fans whenever I like.

 

[brynden29]

So there is no way to wire it so the ECU can control the fans? I do not want to have to worry about switching the fans on and off.

 

[redyute1]

you can just ran the two wires to the sensor and you should be fine,let it idle and see if the fan turn on

 

[brynden29]

It's Green with a black trace, and a black wire. Should be located on the passenger side.

I simply ran a switch to the connector and watch my temps on my logger so I can control my fans whenever I like.

So it is power in one side of the switch and ground on the other. I guess when the temp gets hot enough the switch provides continuity which grounds the green/black wire to turn the fan on.

Does that sound right?

 

[viprez586]

So it is power in one side of the switch and ground on the other. I guess when the temp gets hot enough the switch provides continuity which grounds the green/black wire to turn the fan on.

Does that sound right?

Your right about the thermosensor(AKA thermo-switch).

Straight from the wiring diagram.

1. When the output of the air conditioner
*-- control unit is "LO" (OV)
(when the compressor magnet clutch is
deenergized)
l When the ignition switch is at "ON" , and if
engine coolant temperature rises to 85°C
(185"F), the thermosensor contacts close,
causing current to flow through the radiator
fan motor relay (coil), thermosensor and
ground, causing the radiator fan motor relay
contacts to close.
l Current flows through the radiator fan motor
relay contacts, radiator fan motor and ground,
causing the radiator fan motor to rotate.
2. When the output of the air conditioner
control unit is "HI" (approx. 12V)
(when the compressor magnet clutch is
energized)
l If the therm0 sensor is "ON" when the
engine coolant temperature exceeds 85°C
(185°F). the condenser fan motor control relay
is also "ON", thus the condenser fan as well
as the radiator fan start rotating at a high
speed.

The ECU doesn't operate the fans, the switch(es) does.

 

[viprez586]

you can just ran the two wires to the sensor and you should be fine,let it idle and see if the fan turn on

Correct,by connecting the two wires you are essentially closing the contacts of the thermosensor. You could just bend up a paper clip and have your fans run all the time, or wire a switch to the connector plug.