L16 Temperature Sensor

[Rotarded]

So I recently picked up my 72 Datsun 522 and I’m doing what I do best….taking things apart for no reason. 
 

So on today’s adventure I was replacing the lack of a thermostat and wanted to install the new coolant temp sensor. So I know this retaining nut for the sensor seals it, but does the FSM recommend thread sealant/tape on the nut? I know this grounds so I don’t want to mess with the sensor to housing contact area but I just wanted to see if anyone had input or knows what the OE recommended procedure is.

 

Thank you.

[datzenmike]

If the gauge still functions leave it. Like a lot of things don't fuck with something not broken.

 

Tape may insulate the contact. I should imagine the threads (pipe threads??) are designed to seal by tightening unlike a nut and bolt thread.

[banzai510(hainz)]

9 times out of 10 those Hex nuts are stuck and crack the housing. If the temp gauge works leave it and add a stat if it needs one and use antisieze compound on the bolts.

 

dont take stuff aparts if you dont have too and buy spares when you do youll have it when YOU break it

[Rotarded]

You guys sure have some funny responses. Don’t take stuff apart that doesn’t work, well it doesn’t work and it leaked so that’s why I’m replacing everything?? That’s too funny. Anyways, I’m not afraid of taking things apart I do this for a living. 
 

So getting back to it and I’ll add a backstory now. I have a brand new thermostat housing, thermostat housing cover, thermostat, new bolts, new sensor, new lock down nut, new gaskets…

 

My two questions was if a thread sealant was used on the thread of the nut , and the longer of the two bolts that holds the thermostat cover appears to pass through the timing over so do those threads on that bolt only get thread sealant or rtv?

 

I appreciate everyone’s help, I just wanted to know if anyone knew the factory recommended procedure.

[datzenmike]

You did say:

 

10 hours ago, Rotarded said:

So I recently picked up my 72 Datsun 522 and I’m doing what I do best….taking things apart for no reason. 
 

 

 

You also didn't say it didn't work so what should we assume? I said don't fuck with something NOT broken. Even if not working there are many things to do first to prove that it's the sender and not something else.

 

The two mounting bolts for the thermostat, thread into the head. The timing cover is lower down. These two bolts do not use any thread sealer nor need any. The housing has a gasket to seal the coolant inside it and away from the mounting bolts. You could put a dab of anti-seize on the bolt threads to make future removal easier.

 

 

[banzai510(hainz)]

the 2 bolts that go into the head? Use he stock size bolts or otherwise youll push the timing chain guide and this causes a big issue.

 

Its best to be specific as the 510 and 521 are simple and should not take 5 pages of responses to get a result.

 

I have not used thread tape as the sensor needs to short to the part for the GROUND

[Rotarded]

1 hour ago, datzenmike said:

You did say:

 

 

You also didn't say it didn't work so what should we assume? I said don't fuck with something NOT broken. Even if not working there are many things to do first to prove that it's the sender and not something else.

 

The two mounting bolts for the thermostat, thread into the head. The timing cover is lower down. These two bolts do not use any thread sealer nor need any. The housing has a gasket to seal the coolant inside it and away from the mounting bolts. You could put a dab of anti-seize on the bolt threads to make future removal easier.

 

 

I cant fault you in reading into me taking stuff apart. I didn't think that was the critical part of my post so next time ill be blunt. I started removing the upper cover and snaped a bolt, removed it and then started removing the housing due to it having an ungodly amount of blue rtv and I noticed the short bolt on the t stat housing was rusted even around the shoulder that stays in the housing and the longer bolt came out almost black sludge like. 

 

59 minutes ago, banzai510(hainz) said:

the 2 bolts that go into the head? Use he stock size bolts or otherwise youll push the timing chain guide and this causes a big issue.

 

Its best to be specific as the 510 and 521 are simple and should not take 5 pages of responses to get a result.

 

I have not used thread tape as the sensor needs to short to the part for the GROUND

Yes, I have a full OEM specific kit. OEM hardware, OEM gaskets. Being specific in which way? I am posting this in the "521" section of the forum so I was unaware if this wasn't the correct place. I google and read as much as I can prior to posting anything I assure you.

[Socalman]

6 minutes ago, Rotarded said:

I cant fault you in reading into me taking stuff apart. I didn't think that was the critical part of my post so next time ill be blunt. I started removing the upper cover and snaped a bolt, removed it and then started removing the housing due to it having an ungodly amount of blue rtv and I noticed the short bolt on the t stat housing was rusted even around the shoulder that stays in the housing and the longer bolt came out almost black sludge like. 

 

Yes, I have a full OEM specific kit. OEM hardware, OEM gaskets. Being specific in which way? I am posting this in the "521" section of the forum so I was unaware if this wasn't the correct place. I google and read as much as I can prior to posting anything I assure you.

Use teflon tape, it doesn't matter, yes it needs to be grounded, but I've tested this and it doesn't matter how much tape you put on it, it cuts through the threads when you screw it in and keeps it from having any chance of leaking, is it necessary? probably not on a new housing, but why not? sometimes you need to take things apart to learn things, but it can get costly as well. LOL

[banzai510(hainz)]

3 minutes ago, Socalman said:

but why not? sometimes you need to take things apart to learn things, but it can get costly as well. LOL

Well I assume over time you get corrosion and the ground get weaker. Im not going to say you cant.

 

17 minutes ago, Rotarded said:

I have a full OEM specific kit. OEM hardware,

Whats in a OEM ket? For a thomostat housing?

Just use the stock bolts with correct shank that go thru the housing into the head. Or CORRECT SIZE as it can push on the timing guide as its a exact length fit.. I use the orginal anyways but since you got a kit make sure its the correct length if its just to pretty it up with new bolts

[banzai510(hainz)]

22 minutes ago, Rotarded said:

I noticed the short bolt on the t stat housing was rusted even around the shoulder that stays in the housing and the longer bolt came out almost black sludge like

antiseize is your friend

[banzai510(hainz)]

22 minutes ago, Rotarded said:

I cant fault you in reading into me taking stuff apart. I didn't think that was the critical part of my post so next time ill be blunt.

Its a compitition.see who gets the fix first. Kinda like Name that tune but in reverse. You give the most clues and well try to hit it in 1 response

[Roadster driver]

So with regard to the bolts going into the cylinder head, I would put some old school Permatex aviation formula gasket sealer as the threads are in a wet place “oil splashing around “.  It will keep oil from seeping at the head of the bolts. With regard to the thermostat cover bolts I would recommend you use a marine grease or anti seize to prevent any corrosion. The temperature sender has a conical seat to seal it and requires no sealant just clean dry surface and it will be fine and produce good continuity for the temperature senders signal. Good luck with your repair. 
 

Dave

[Rotarded]

28 minutes ago, Roadster driver said:

So with regard to the bolts going into the cylinder head, I would put some old school Permatex aviation formula gasket sealer as the threads are in a wet place “oil splashing around “.  It will keep oil from seeping at the head of the bolts. With regard to the thermostat cover bolts I would recommend you use a marine grease or anti seize to prevent any corrosion. The temperature sender has a conical seat to seal it and requires no sealant just clean dry surface and it will be fine and produce good continuity for the temperature senders signal. Good luck with your repair. 
 

Dave

You sir deserve an award. Thank you for the clarification. I have some various sealants for threads I will start looking into it. 

[datzenmike]

Water can't get out on the housing bolts, there's no where for it to go. Gasket seals the housing and the top of the bolt is tight to the top of the housing. Anti seize only. If you use sealer you'll never get that housing bolt back out later if needing repair.

 

This is what happens. Both bolts seized or perhaps sealer and seized so the only way off is to cut it off. Teflon tape might work, don't forget the temperature sender grounds to the head through the bolts.

 

[mainer311]

I use teflon pipe dope on the sender nut. It’s thick enough to seal, but you’ll still get ground through it. Just hit it with a multimeter after and verify there’s not a lot of impedance.

[Rotarded]

All new parts are on and installed, I did the hoses and water pump while I was at it. Truck is running amazing and the coolant gauge even works a little, I did end up using a small amount of liquid PTFE tape. I am going to do the VR mod on the back of the gauge cluster next to see if that resolves the remainder of the fuel gauge/coolant temp/turn signal issues.