temp gauge question
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Mountain Pass
Joined: Mar 2015
Posts: 184
Likes: 5
temp gauge question
how long does it take the stock temp gauge to register?
ive swapped my 400 for a 390. and my engine seems like it getting hot fast but my temp gauge isn't reading. i think i'm just being paranoid and not letting it run long enough though.
ive swapped my 400 for a 390. and my engine seems like it getting hot fast but my temp gauge isn't reading. i think i'm just being paranoid and not letting it run long enough though.
Laughing Gas
Joined: Jun 2016
Posts: 855
Likes: 56
From: Des Moines, Washington
When it's properly filled with coolant, mine can take a few minutes, maybe up to 5 before it's into the temp zone. The first two or three starts after draining and refilling it never came up and yet blew steam and then coolant out the radiator. A sure sign that it had air trapped behind the thermostat.
Michael
Michael
Laughing Gas
Joined: Jun 2016
Posts: 855
Likes: 56
From: Des Moines, Washington
Different sender for light VS gauge.
Gauge is a variable resistance to ground, light is a switch that closes at setpoint. You can test from plug at sender back to gauge by grounding plug. Gauge will go full hot when grounded, full cold when not connected.
If you have an ohm meter, you can read from pin on sender to ground, Switch style sender will be open, gauge style sender will have some resistance, probably kinda high.
Michael
Gauge is a variable resistance to ground, light is a switch that closes at setpoint. You can test from plug at sender back to gauge by grounding plug. Gauge will go full hot when grounded, full cold when not connected.
If you have an ohm meter, you can read from pin on sender to ground, Switch style sender will be open, gauge style sender will have some resistance, probably kinda high.
Michael
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Postmaster
Joined: Nov 2011
Posts: 2,553
Likes: 10
Fitting a simple mechanical temp gauge would tell you what is going on... at least as a diagnostic. A $10-15 Sunpro for example from your local AP store.
Also agree it may take a heat/cool cycle or two to get the air out... re-check coolant level after it cools each time.
Also agree it may take a heat/cool cycle or two to get the air out... re-check coolant level after it cools each time.
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Fleet Mechanic
Joined: Aug 2004
Posts: 1,311
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From: Nevada
390
The temp sender behind the dizzy should be legit.... My 390 will start to register after about 5 minutes or so, reaches operating temp with my 190 Stat after about 12-15 minutes-ish..... depending on shop temp..... I have a stat elbow fitting gauge sender that takes the 'open stat' temp also..... nice to have both, with the stock temp, your kinda guessing ..... but you should be seeing something after 5-10 mins..... 
If i remember correctly the sender color mark was green.....
If i remember correctly the sender color mark was green.....
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