as the title reads... my engine temp needle is bouning between cold and normal operating temp... and i mean literally bouncing.. not a gradual sweep. could this be a sign of a bad themostat or an ecu problem? the motor is a built b18c5... im not too sure but it may or may not have a spoon T-stat... my brother and his shop built the motor so im not totally familiar with all the parts used for the build up... thanx for any info in advance fellas

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NorthernXposure &raquo;</TD></TR><TR><TD CLASS="quote">
as the title reads... my engine temp needle is bouning between cold and normal operating temp... and i mean literally bouncing.. not a gradual sweep. could this be a sign of a bad themostat or an ecu problem? the motor is a built b18c5... im not too sure but it may or may not have a spoon T-stat... my brother and his shop built the motor so im not totally familiar with all the parts used for the build up... thanx for any info in advance fellas

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Gauge or sensor is probably loose! Check the wiring yet (ground and sensor lead?) Any other gauges flakey?

 

just that guage is acting up... and car is running fine.. but ill check for a loose wire or bad ground thnx

 

I don't think the computer uses that gauge for anything (maybe fuel/timing? Doubt it, IAT is more important) so even if it was bad the car shoud run fine.

 

Aftermarket thermostat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ITR 2K &raquo;</TD></TR><TR><TD CLASS="quote">Aftermarket thermostat.</TD></TR></TABLE><TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NorthernXposure &raquo;</TD></TR><TR><TD CLASS="quote">and i mean literally bouncing.. not a gradual sweep.</TD></TR></TABLE>

Doubt it.

Maybe you can have a friend wiggle wires while you watch the gauge.. does it "bounce" more when you're moving, or does it do it while idling? Is it a consistent bounce or intermittent?

 

Mine did the same thing after I reinstalled my head... ended up being a loose connection on the sensor. Car ran find but the guage was all over the place. I am 95% sure thats your problem. If not that, do you have some air in your cooling system causing bad temp readings?

Hope this helps, Ryan

 

Ditto, I somehow loosened mine during my clutch replacement and had the same symptoms. Pushed it back on and the gauge has worked perfectly ever since.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CW-ITR-329 &raquo;</TD></TR><TR><TD CLASS="quote">Mine did the same thing after I reinstalled my head... ended up being a loose connection on the sensor. Car ran find but the guage was all over the place. I am 95% sure thats your problem. If not that, do you have some air in your cooling system causing bad temp readings?

Hope this helps, Ryan</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">

Doubt it.

Maybe you can have a friend wiggle wires while you watch the gauge.. does it "bounce" more when you're moving, or does it do it while idling? Is it a consistent bounce or intermittent?</TD></TR></TABLE>

its an intermittent bounce.. it does it when its idling and when moving....
funny thing is that i havnt done any under hood work to in for a while and then all of the sudden it starts bouncing.... hopefully i can figure it out today.. if now i may throw a new T stat into it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NorthernXposure &raquo;</TD></TR><TR><TD CLASS="quote">
as the title reads... my engine temp needle is bouning between cold and normal operating temp... and i mean literally bouncing.. not a gradual sweep. could this be a sign of a bad themostat or an ecu problem? the motor is a built b18c5... im not too sure but it may or may not have a spoon T-stat... my brother and his shop built the motor so im not totally familiar with all the parts used for the build up... thanx for any info in advance fellas

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i am really sure its the gauge, my GF just had the same thing happening in her car. its teh gauge, you don;t have to fix it right away, but you will never know if you overheating if you don't

go to a mechaninc, they have a laser gun they can point at different parts of your engine FOR FREE (or they are cheap *******) and tell you if its running at the right temp. if it is, the thermostat should be fine!

 

well i pulled the plug that goes into the head and put it back it.... seems to have stopped for now... not to sure how it could have come looose... but at least is back to working order thanks for the help fellas

 

mine does the same thing, it also runs 100% I just rebuilt my motor and its more than likely a loose wire. Goodluck