Instead of tapping the S52 head for coolant temp sensor...

[KangamangusDriver]

I was speaking with one of my friends who recently did the OBD2-OBD1 conversion on a S52 and I asked him what he did about the second coolant temp sensor.

He told me that you can remove the threaded fitting for the coolant hose that cools the the throttle body(one we usually bypass).
-Use this port for the coolant temp sensor.

Once that is done, take the sensor and run a die down the threads to make them smaller. When you get it the correct size you can screw it into the head. no drilling or tapping of the head necessary.

This was tried and tested.

Hope this helps, what do you guys think?

[s52e368]

you c ould get an alum tstat housing and tap it ...
i did

[dmoffitt]

I think it's a very good idea (in theory, haven't seen it). What might be better is to modify the head when it's off the engine to fit the regular sensor though, rather than having to customize a sensor...

[aeryk7]

Sounds like a good idea to me.

[Jason89i]

He told me that you can remove the threaded fitting for the coolant hose that cools the the throttle body(one we usually bypass). ........what do you guys think?

bypassing the tbody coolant tube is not a good idea for cars in the northern climate.

if you do not heat the tbody in the winter, you will get frost / ice buildup. humidity will stick to the butterfly. engine will choke, plate will stick, car will be posessed......they you let it sit, ice thaws, water drians into the inake, now the car runs normal.

cheers, jason

[trent]

Just tap the damn head. What is the big deal? Takes 5 min.

[aeryk7]

Just tap the damn head. What is the big deal? Takes 5 min.

Using a dye on the original sensor is more time efficient , you rethread the original sensor and it screws into a hole already tapped in the head. I could seriously do this with my current setup in 5 minutes had i had the dye in hand. If the engine is cool i would even be able to put the sensor in with out barely losing any coolant unlike if you were to tap the head and drain all existing coolant , metal shavings everywhere,cleaning them up ,etc. Not to mention in order to tap the head you would have to remove the intake manifold.

[trent]

Using a dye on the original sensor is more time efficient , you rethread the original sensor and it screws into a hole already tapped in the head. I could seriously do this with my current setup in 5 minutes had i had the dye in hand. If the engine is cool i would even be able to put the sensor in with out barely losing any coolant unlike if you were to tap the head and drain all existing coolant , metal shavings everywhere,cleaning them up ,etc. Not to mention in order to tap the head you would have to remove the intake manifold.

Most people realise this is a problem before they install the motor. I do agree, much faster when the motor is out and/or just a long block.

[matt]

Using a dye on the temp sensor is just going to leave you with a different colored sensor. You'd probably rather use a die to change the threads on it.

I'll second the suggestion to not bypass the throttle heater. It helps the motor warm up faster, and prevents the intake charge from freezing in the throttlebody under the proper conditions.

[aeryk7]

Most people realise this is a problem before they install the motor. I do agree, much faster when the motor is out and/or just a long block.

I was thinking about 3.2 in e36 m3 and people converting to obd1 not really thinking about e30 guys having to pretty much go obd1 anyway.

[LINUS]

Just tap the damn head. What is the big deal? Takes 5 min.

+1

Makes it a factory setup.

Or else cheat completely and get a Zionsville/Turner harness adapter. At least you still heat the t-body that way.

[aeryk7]

Just a little curious how come you couldnt just replace the doulble switched sensor for the obd1 sensor and uncrew the plug and put the sender in its place? Arent these heads cast the same ?

I am sorry if i am ignorant to this cause but arent all these sensor holes identical to either head cant you just swap the obd1 sensors for the the obd2 and call it a day.

**********OBD1************




**********OBD2*************

[aeryk7]

Turner says that most m52 s52 only have two hole instead of three in which case the pictures confused me . Im good now.

[ian332isport]

Or else cheat completely and get a Zionsville/Turner harness adapter. At least you still heat the t-body that way.

Does that take into account the different resistance value of the E36 sensor though ?

Ian.

[Jason89i]

Does that take into account the different resistance value of the E36 sensor though ?

Ian.

nope. different resistance on e30 vs. e36 temp guage sensors.

jason