Hello! I had an issue on my 2002 H-6 Outback where it wouldn't start, it would crank and crank, but not start. I would give it some gas and it would start right up. So I replaced the engine coolant temperature sensor. Now it starts up fine but the dash temp gauge will hardly get above cold. Here's what it looks like after about 7 miles of driving: http://imgur.com/4ifXrzJ . The car is heated up so I know its not a thermostat issue. I searched and couldn't find anything, anyone know how to calibrate the dash gauge to the new sensor?

Do you have good heat in the car?? There is no calibration of dash gauge to new sensor. It may just be coincidence this has happened with new sensor installed, but it sounds like your thermostat is bad

Hello! I had an issue on my 2002 H-6 Outback where it wouldn't start, it would crank and crank, but not start. I would give it some gas and it would start right up. So I replaced the engine coolant temperature sensor. Now it starts up fine but the dash temp gauge will hardly get above cold. Here's what it looks like after about 7 miles of driving: http://imgur.com/4ifXrzJ . The car is heated up so I know its not a thermostat issue. I searched and couldn't find anything, anyone know how to calibrate the dash gauge to the new sensor?

There are 2 coolant temp sending units. One feeds data to the gauge on the dash. The other feeds data to ECU. I think the one for the gauge won't affect if the car can start or not. It simply controls the gauge. The sending unit for the ECU will affect starting of the car, but won't affect the gauge. If the one you replaced indeed solved your starting problem, it shouldn't cause the gauge needle to stay so low after 7 miles of driving. Are you saying the gauge needle was higher before replacing the sending unit?

i have noticed in post 2000 subaru legacy, the engine temp sensor and the dash gauge are in the same unit, with 3 prongs. The car i fixed always showed a pegged temp gauge. Replacing it solved the matter, but it took a few cycles for the temp gauge to correct. Perhaps it was a corroded pin in my case.

I'd be concerned that I got a bad new part or there was a wiring problem. maybe temporariliy put the old one back in?

There are 2 coolant temp sending units. One feeds data to the gauge on the dash. The other feeds data to ECU. I think the one for the gauge won't affect if the car can start or not. It simply controls the gauge. The sending unit for the ECU will affect starting of the car, but won't affect the gauge. If the one you replaced indeed solved your starting problem, it shouldn't cause the gauge needle to stay so low after 7 miles of driving. Are you saying the gauge needle was higher before replacing the sending unit?

To me a good starting point is to return the engine coolant temperature sensor that you just installed, and get a new one. Tell them you think it is the source of a low temp gauge read out. If the problem started with the engine coolant temperature sensor then putting in another one may well fix it.

To me a good starting point is to return the engine coolant temperature sensor that you just installed, and get a new one. Tell them you think it is the source of a low temp gauge read out. If the problem started with the engine coolant temperature sensor then putting in another one may well fix it.

You're probably right, the one I got may have the resistance set wrong for some reason. I'll try this when I get a chance. Thanks!

 

I'd be concerned that I got a bad new part or there was a wiring problem. maybe temporariliy put the old one back in?

I tried putting the old one back in, the temp gauge returned to normal but then the starting issue returned. Thats why I was wondering if I needed to calibrate the resistance or something on the new one to report correctly on the dash. Thanks for the reply!

 

i have noticed in post 2000 subaru legacy, the engine temp sensor and the dash gauge are in the same unit, with 3 prongs. The car i fixed always showed a pegged temp gauge. Replacing it solved the matter, but it took a few cycles for the temp gauge to correct. Perhaps it was a corroded pin in my case.

Are you saying that one day it just got the temp right? And yes the one I replaced was a three pronged unit. I believe it may be the same thing we replaced. Thanks for the reply!

 

There are 2 coolant temp sending units. One feeds data to the gauge on the dash. The other feeds data to ECU. I think the one for the gauge won't affect if the car can start or not. It simply controls the gauge. The sending unit for the ECU will affect starting of the car, but won't affect the gauge. If the one you replaced indeed solved your starting problem, it shouldn't cause the gauge needle to stay so low after 7 miles of driving. Are you saying the gauge needle was higher before replacing the sending unit?

Yes, the needle was usually right in the middle of the gauge before replacing the unit. In all the diagrams I saw of this car I only saw one engine coolant temperature sensor though. Thanks for the reply!

 

Do you have good heat in the car?? There is no calibration of dash gauge to new sensor. It may just be coincidence this has happened with new sensor installed, but it sounds like your thermostat is bad

 

I do have good heat in the car, so I am not sure that is is a thermostat issue, when I got to work this morning I popped the hood and the engine was hotter than I would want to touch, granted that doesn't mean it is where it needs to be. Being that thermostats are only around 12$ I'll look into one, thanks for the reply!

The sensor is out of range. This happens fairly often with the cheaper sensors. Try another new one, preferably a different brand.

 

DO NOT USE A $12 THERMOSTAT IN A SUBARU!!! It will cause overheating problems and leave you worse off than you started.

You're probably right, the one I got may have the resistance set wrong for some reason. I'll try this when I get a chance. Thanks!

 

I tried putting the old one back in, the temp gauge returned to normal but then the starting issue returned. Thats why I was wondering if I needed to calibrate the resistance or something on the new one to report correctly on the dash. Thanks for the reply!

 

Are you saying that one day it just got the temp right? And yes the one I replaced was a three pronged unit. I believe it may be the same thing we replaced. Thanks for the reply!

 

Yes, the needle was usually right in the middle of the gauge before replacing the unit. In all the diagrams I saw of this car I only saw one engine coolant temperature sensor though. Thanks for the reply!

 

 

I do have good heat in the car, so I am not sure that is is a thermostat issue, when I got to work this morning I popped the hood and the engine was hotter than I would want to touch, granted that doesn't mean it is where it needs to be. Being that thermostats are only around 12$ I'll look into one, thanks for the reply!

Since you have good heat in the cabin, your thermostat is just fine. Don't need to replace it.

The sensor is out of range. This happens fairly often with the cheaper sensors. Try another new one, preferably a different brand.

 

DO NOT USE A $12 THERMOSTAT IN A SUBARU!!! It will cause overheating problems and leave you worse off than you started.

 

Hm good to know, do you have any recommended brands?

Since you have good heat in the cabin, your thermostat is just fine. Don't need to replace it.

Yeah that's what I figured,

Subaru OE is best.

Aftermarket options are available, from Stant labaled "Exact-stat".

Gates also makes an OE equivalent, part number 34012.

These are usually $20 or slightly more at parts stores. I do know you can get the Gates from Rockauto for around half that, shipping is a few $ extra.

MilesFox, on 10 Feb 2014 - 12:35, said:

 

i have noticed in post 2000 subaru legacy, the engine temp sensor and the dash gauge are in the same unit, with 3 prongs. The car i fixed always showed a pegged temp gauge. Replacing it solved the matter, but it took a few cycles for the temp gauge to correct. Perhaps it was a corroded pin in my case.

 

Are you saying that one day it just got the temp right? And yes the one I replaced was a three pronged unit. I believe it may be the same thing we replaced. Thanks for the reply!

In my case, dude's car would show hot and begin to fail start from hot start after a few hours of urban driving (food delivery). It left him stuck needing jumpstarts, and the car would start after it sat for a little bit. I suggested he put the pedal down while cranking, and that got him started until we arranged for me to replace the temp sensor per my suggestion.

 

After replacing the sensor, the temp gauge would peg, although it solved the hot start and stalling issue. He had the same toruble agian with the hot start. The next week i inspected my work, an plugged and unplugged the terminal and wiggled it around. After a few days he came back and said it was working properly. So the variable was poking around at the same installed part. I was doubly sure to look up the part number to make sure it was correct, and it is the correct piece for aftermarket supply (NAPA echlin)

Okay thank you guys a lot you've all been really helpful. I'm going to try ordering the OEM duplicate from rock auto (best place for parts BTW).