91coMANche Posted January 3, 2011 Share Posted January 3, 2011 I was just about to start drilling and tapping the thermostat housing when I realized that I could just as easily find a spot on the block thats already drilled and tapped. I know there are two coolant drains on the side of the block that is shared with the intake/exhaust. Are there any other drains on the block? I would get a reducer to fit the sensor into the hole. Are there any other drain ports that are away from the exhaust side? I am a little scared of running a wire down near the header. Link to comment Share on other sites More sharing options...
jpdocdave Posted January 3, 2011 Share Posted January 3, 2011 what's wrong with the sensor port already in the head where the sensor is from the factory? Link to comment Share on other sites More sharing options...
91coMANche Posted January 3, 2011 Author Share Posted January 3, 2011 There is nothing wrong with the stock port in the head if I was still running the weeny 190hp 1991 4.0 :D Lucky me is updating and upgrading to all my dream Jeep parts and one of them was an upgrade to a 98 ZJ 4.0. These did not use a sensor in the head. So where the hole was in the 91 head is just a cast-over on the 98 head. I am not sure what the 98 ZJ used to fire the temperature gauge but it didn't come from the head. I am pretty sure it would just use the main coolant temperature sensor. Anyway, are there any block drains except for the two on the exhaust side of the block? Link to comment Share on other sites More sharing options...
ParadiseMJ Posted January 3, 2011 Share Posted January 3, 2011 There is nothing wrong with the stock port in the head if I was still running the weeny 190hp 1991 4.0 :D Lucky me is updating and upgrading to all my dream Jeep parts and one of them was an upgrade to a 98 ZJ 4.0. These did not use a sensor in the head. So where the hole was in the 91 head is just a cast-over on the 98 head. I am not sure what the 98 ZJ used to fire the temperature gauge but it didn't come from the head. I am pretty sure it would just use the main coolant temperature sensor. Anyway, are there any block drains except for the two on the exhaust side of the block? No. Not unless you pop out a freeze plug. Is there no sensor on the t-stat housing itself? Just the one sensor on the 97+ 4.0. Link to comment Share on other sites More sharing options...
91coMANche Posted January 3, 2011 Author Share Posted January 3, 2011 The 97+ HO engines use a single temperature sensor that both tells the computer whether to be in open or closed loop and to feed the dash gauge. I have a 1998 4.0 (ridiculously amazing and I suggest the swap to everyone) and so I don't have a head with a hole pretapped for a temperature sensor for the gauge. I will drill and tap a thermostat housing and install my sensor in that. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now