BB water temp sending unit?
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,914
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
BB water temp sending unit?
How far does the sending unit screw into the head? I could probably get another 1/2 turn on this one. Is it sticking out too far? I think it's only got about 4 threads into the head.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Re: BB water temp sending unit? (Jughead)
they certainly don't go in all the way, just make sure it doesn't leak (where's your teflon??) and it's in a decent amount. Moderately tightening it will be sufficient.
Yours looks to be almost far enough, I'd go a tad further to be sure (like 2 more threads). They are NPT threaded which is a tapered thread. I wouldn't use teflon tape though, use the liquid variant, the tape usually makes them really hard to get in far enough
[Modified by Twin_Turbo, 7:14 AM 3/16/2004]
Yours looks to be almost far enough, I'd go a tad further to be sure (like 2 more threads). They are NPT threaded which is a tapered thread. I wouldn't use teflon tape though, use the liquid variant, the tape usually makes them really hard to get in far enough
[Modified by Twin_Turbo, 7:14 AM 3/16/2004]
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,914
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Re: BB water temp sending unit? (Twin_Turbo)
Thanks Marck, I'm going to try to get it a little tighter. I will use liquid sealer, this was just a trial fit. It started to get real tight after only a few turns.
Race Director
Joined: Apr 1999
Posts: 10,861
Likes: 713
From: Beverly Hills/Pine Ridge Florida
Re: BB water temp sending unit? (Jughead)
Be careful with teflon or sealer. The sender must ground to the head. Too much teflon and/or sealer will prevent a good ground, and then your temp gauge won't work properly, if at all. Chuck
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Re: BB water temp sending unit? (Chuck Gongloff)
:iagree: That's why I use liquid sealer because teflon tape tends to isolate the senders more often. I've had that a couple of times, then switched to liquid teflon sealer and never had those problems again. I only coat the first 2 or 3 threads with sealer
Thread Starter
Senior Member since 1492
Joined: Aug 2000
Posts: 87,914
Likes: 156
From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Re: BB water temp sending unit? (Chuck Gongloff)
Be careful with teflon or sealer. The sender must ground to the head. Too much teflon and/or sealer will prevent a good ground, and then your temp gauge won't work properly, if at all. Chuck
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: BB water temp sending unit? (Twin_Turbo)
If you are not happy with the depth of engagement run a pipe tap into the hole and enlarge the theads. They are tapered and a turn or two with a tap just allows the unit to go in a little further.
As for teflon tape it is the best. You can remove it again in a few years. The teflon paste or pipe paste tends to freeze the plug making future removal very difficult
[Modified by norvalwilhelm, 7:49 PM 3/16/2004]
As for teflon tape it is the best. You can remove it again in a few years. The teflon paste or pipe paste tends to freeze the plug making future removal very difficult
[Modified by norvalwilhelm, 7:49 PM 3/16/2004]
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: BB water temp sending unit? (Jughead)
Thanks Marck, I'm going to try to get it a little tighter. I will use liquid sealer, this was just a trial fit. It started to get real tight after only a few turns.
Made the mistake of using liquid teflon sealent on the mustang T5 drain and fill plugs. After a season I tried removing them and they are welded into place. I was honestly afraid of splitting the plugs in half with the length of bar I was using trying to break them free.
Luckily I used teflon tape on the vet and every plug comes right out.
Watch this Marck.
My son is a maintenance supervisor at a large plant and he warned me about the dangers of using pipe sealant paste.
'He was right.
Made the mistake of using liquid teflon sealent on the mustang T5 drain and fill plugs. After a season I tried removing them and they are welded into place. I was honestly afraid of splitting the plugs in half with the length of bar I was using trying to break them free.
Luckily I used teflon tape on the vet and every plug comes right out.
Watch this Marck.
My son is a maintenance supervisor at a large plant and he warned me about the dangers of using pipe sealant paste.
'He was right.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: BB water temp sending unit? (Twin_Turbo)
they certainly don't go in all the way, just make sure it doesn't leak (where's your teflon??) and it's in a decent amount. Moderately tightening it will be sufficient.
[Modified by Twin_Turbo, 7:14 AM 3/16/2004]
[Modified by Twin_Turbo, 7:14 AM 3/16/2004]
NO! NO! Dont use teflon tape.... It will not make a good ground and may not give accurate readings. It is a tapered thread so you just need to tighten it a little. Be carefull because if you keep tightening the manifold can crack. There are a lot of senders that are not calibrated correctly. The Delco replacement is way off. If your old one was correct you may need to use it. This has been an issue for quite a while.
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: BB water temp sending unit? (bluevetteman)
"Be careful with teflon or sealer. The sender must ground to the head. Too much teflon and/or sealer will prevent a good ground, and then your temp gauge won't work properly, if at all. Chuck"
What a good tip. Maybe all the sensors that are wacko are really not that far off, just not grounded. I used teflon (ARP) thread sealer on the last one I put in and it is 50% off temp. Worth a try to clean the threads and put back in - only PITA because you have to drain the radiator or spill on the floor. Thanks Chuck.
What a good tip. Maybe all the sensors that are wacko are really not that far off, just not grounded. I used teflon (ARP) thread sealer on the last one I put in and it is 50% off temp. Worth a try to clean the threads and put back in - only PITA because you have to drain the radiator or spill on the floor. Thanks Chuck.
