lt1 conversion problem.......coolant sensor
Thread Starter
Instructor
Joined: Oct 2002
Posts: 214
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From: spring tx
lt1 conversion problem.......coolant sensor
i did a conversion installing a lt1 out of a 95 with lt4 top end swap all into a 72 nova.....now i am using a autometer coolant temp gauge and sending unit..first i installed this into the drivers side cylinder head and it reads about 50-60 degrees higher than what the ecm reads when i took it to a shop and pluged it into their scanner. i then took vettedans example in his website and did a swap to a 95zr1 coolant sending unit in the water pump and used the extra lead...when the zr1 sending unit would read 150 the auto meter unit would read 210 when the autometer unit would read 250 the zr1 unit would read 155-160......does anyone know how to correct this or where to locate a sending unit to get a proper reading, like can i tap the water pump somewhere and install the sending unit....would i get a good reading if i installed a t-fitting where the sending unit that the ecm uses goes into the water pump. i have a seperate setup to control the fans on my car, does the ecm need the sending unit for anything other than fan control?
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: lt1 conversion problem.......coolant sensor (blue72lt4sc)
First of all the Engine coolant sensor for the PCM is located in the water pump. Your temp sensor for the gauge is mounted in the cylinder head. You will see a higher temperature there than the ECT does at the water pump. You could replace the thermostat housing with one that has a threaded hole in it for a temp sensor to be installed there. If you install it there the readings should be very similar. The only other reason that they gauge and what the PCM sees being so far off is that the Autometer sensor is not calibrated to the gauge or vice versa.
Thread Starter
Instructor
Joined: Oct 2002
Posts: 214
Likes: 0
From: spring tx
Re: lt1 conversion problem.......coolant sensor (tjwong)
i understand the placement of each sensor and why they are not accurate but thanks.....i didnt think of tapping a hole in the thermostat housing, good idea
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: lt1 conversion problem.......coolant sensor (blue72lt4sc)
No I didn't for you to drill and tap your existing thermostat housing. You can go to NAPA and get one that is made with the sensor provisions built in.
