Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Classic Industries
American Auto Wire
Danchuk Catalog
Hellwig Products IncPerformance Rod & CustomNu-Relics Power Windows

Username Post: 2006 Silverado 6.0 weird behavior - coolant temperature sensor        (Topic#361982)
Senior Moderator
Posts: 29201
Age: 50
Loc: Texas
Reg: 08-01-03
08-01-20 07:02 AM - Post#2800061    

I'm used to CTS issues on older trucks like TBI's, they're notorious for it. The sensor goes bad or its ground gets damaged, resistance goes high, and they read full cold regardless of coolant temp, fuel mixture goes stupid fat, even to the point of fouling the plugs and stalling the engine. However, I have not seen many threads on newer engines particularly LS's having similar issues. Also, on the older trucks, the dash gauge and the PCM input are two separate units.

So on my 2006 SS 6.0 the symptoms were - seemed to be running/behaving fine, was hustling down the highway headed to work and noticed the temperature gauge was all the way down at 160, shouldn't have been as I'd already been driving for at least 15 minutes and it's nice and warm here now. As I was looking at the gauge, the engine suddenly stumbled just a moment like a hard misfire, then the gauge started rising towards 200 or so and was fine from there on out. Next day headed home stuck in traffic, it suddenly surged as the idle kicked up to around 1K, looked down and as expected the temp gauge was low again.

Got home and started researching, found a several-year-old post on Performancetrucks forum describing similar issues, with this advice:

  • Mrgoodwrench3 Said:
I would check the coolant temp sensor. Make sure the connector terminals are clean and tight. Also make sure the wiring is not touching the #1 spark plug wire.

I went to check and noticed the CTS wire rubbing against the #1 spark plug wire. I gave the sensor wire a new bend to keep it away from the plug wire, then unplugged it and shot a little DeOxit in there just for good measure. Sensor looks 100K+ mile original and I figured the possibility it took some spark leakage is real, so I ordered another one. In the meantime though I've put another 40+ miles on it and no issues. So while the poster of the original thread didn't update, it sure sounds like he was having the same issue (bad CTS or possibly spark leakage through wires touching) and I can see how the same could happen to others.


06 Silverado ISS / 06 Silverado SS / 06 300C SRT8

Super Senior Member
Posts: 14629
Loc: Baltimore, MD
Reg: 11-27-04
08-01-20 08:32 AM - Post#2800071    
    In response to someotherguy

Good advice Richard. Might be something you wouldn’t think to look for.

Friends don’t let friends drive Fords.

1999 Silverado Z71 4X4 extra-cab short bed
1983 Malibu Fauxmad - tubbed
1978 El Camino Kustomized
1972 Monte Carlo
1957 210 handyman wagon
1957 Nomad sport wagon
1957 Cameo Carrier

Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.62 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 11:33 PM