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Old 11-30-2015, 01:22 AM   #1
lowrodderchev
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bad gauge or bad thermostat p

So my trucks been doing something weird lately, my aftermarket temp gauge is jumping back and fourth from 195 to 245 every few minutes so bad gauge or bad thermostat? Its not boiling over any suggestions thanx in advance guys
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Old 11-30-2015, 11:31 AM   #2
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Re: bad gauge or bad thermostat p

Drive it a day or two with the thermostat out. That's the easiest way I know to tell quick. If it quits jumping around the thermostat was sticking.
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Old 11-30-2015, 11:35 AM   #3
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Re: bad gauge or bad thermostat p

Thanx bruiser I'll try that out today
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Old 12-02-2015, 12:55 AM   #4
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Re: bad gauge or bad thermostat p

So far so good mornings suck trying to warm it up. I think I'm do for a new motor either way
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Old 12-02-2015, 03:10 PM   #5
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Re: bad gauge or bad thermostat p

What else is it doing?
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Old 12-02-2015, 03:49 PM   #6
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Re: bad gauge or bad thermostat p

Last time I change my plugs they were looking pretty corroded
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Old 12-02-2015, 04:06 PM   #7
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Re: bad gauge or bad thermostat p

what happens when you ground out the wire from the sending unit ?
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Old 12-02-2015, 04:14 PM   #8
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Re: bad gauge or bad thermostat p

Its a sunpro mechanical gauge.im guessing its a bad thermostat since the temp isn't bouncing around
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Old 12-02-2015, 04:17 PM   #9
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Re: bad gauge or bad thermostat p

summit had the sunpro mini gauges on sale for 8 dollars last month. glad you got it figured out
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Old 12-02-2015, 06:33 PM   #10
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Re: bad gauge or bad thermostat p

No I didn't LOL just got home from hitting a few stores gauge was sitting at 135 for about 2 miles then jumped up to 200 which isn't bad but seems strange that for it to not stay steady since I don't have thermostat in it
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Old 12-02-2015, 07:46 PM   #11
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Re: bad gauge or bad thermostat p

That's odd. The bad thing about that is it swung proportionately, so you can't really rule out it's not accurate. I don't know though.
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Old 12-02-2015, 08:07 PM   #12
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Re: bad gauge or bad thermostat p

Maybe a bad temperature switch
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Old 12-04-2015, 12:27 PM   #13
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Re: bad gauge or bad thermostat p

yep I'm shooting for bad gauge. this morning took my son to school it shot up to 250 for a minute then shot back down to 180. still not running a thermostat. going to order a new gauge from summit and put my thermostat back in.

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Old 12-04-2015, 12:27 PM   #14
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Re: bad gauge or bad thermostat p

sorry for the upside down pix nor sure why it did that
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Old 12-04-2015, 01:18 PM   #15
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Re: bad gauge or bad thermostat p

semi hijack.

anyone experience a low reading on the gauge even after a new sensor?

I was running a 180 and upped it to a 195. I still read 180 on the gauge and ~175-180 when data logging.

I believe this is still affecting my idle and sometimes closed loop.


I am on my second sensor, same reading.

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Old 12-04-2015, 01:26 PM   #16
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Re: bad gauge or bad thermostat p

Quote:
Originally Posted by chris989 View Post
semi hijack.

anyone experience a low reading on the gauge even after a new sensor?

I was running a 180 and upped it to a 195. I still read 180 on the gauge and ~175-180 when data logging.

I believe this is still affecting my idle and sometimes closed loop.


I am on my second sensor, same reading.

Thanks
Chris
I read somewhere they're not always as accurate as what they're advertised to be. To verify, put it in a pot of water on the stove and put the heat on high. Then measure the water temp when the thermostat opens.
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Old 12-15-2015, 11:41 AM   #17
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Re: bad gauge or bad thermostat p

Quote:
Originally Posted by BRUISER View Post
I read somewhere they're not always as accurate as what they're advertised to be. To verify, put it in a pot of water on the stove and put the heat on high. Then measure the water temp when the thermostat opens.
I bought another sensor, (3rd one) and it now reads ~195. Passed smog easily.
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