coolant temp sensor-not where its supposed to be (?)

[sunliner]

I have a 2006 Trailblazer 6 cylinder.
Cannot find the coolant temp sensor to save my life. I know it's supposed to be just above the thermostat but mine has a blank spot in that location. wonder if I've got a different motor (truck was bought used). where else could the sensor be, or am I just blind?
see the attachment please
thanks

 

[BlazingTrails]

The alternate location is on the passenger side of the engine towards the back. it should be the same part, so if you have the new one you can use it as a reference to find it on your blcok.

good luck!

Brandon


It is #3 in this diagram

 

[The_Roadie]

Evil GM moved it in 2006 to the other side of the block, and way to the rear. I apologize for their insanity.

 

[The_Roadie]

Did *I* just get scooped by typing too slowly!?!?!?!?!?!?!?!

Man, I gotta do something to slow down these helpful noob mod wannabes.

 

[BlazingTrails]

Now i'm a helpful noob mod wannabe??

-wingman

 

[sunliner]

oh wow...that's gonna be fun to get to. I do thank you much for your help though!

 

[BlazingTrails]

Anytime Brother, we're all here to help!

 

[Robbabob]

Now i'm a helpful noob mod wannabe??

-wingman

 

[sunliner]

might just wait...already have the alt out to do the thermostat. might as well finish that and save this for anther time. sensor might be fine anyway, just was gonna do it at the same time because I thought it was right by the t stat. thanks again

 

[The_Roadie]

Not allowed.

You asked us about it. Now you're compelled to do the work. We insist.

 

[djthumper]

Did *I* just get scooped by typing too slowly!?!?!?!?!?!?!?!

Man, I gotta do something to slow down these helpful noob mod wannabes.

Now i'm a helpful noob mod wannabe??

-wingman

Sounds like someone is getting a new member title...

 

[Robbabob]

Sounds like someone is getting a new member title...

Check out his name/above his picture!

 

[BlazingTrails]

when will the hazing stop.......

 

[IllogicTC]

Further reading:

The ECT sensor was moved to the location on your vehicle beginning with the 2006 model, likely done as part of their redesign. If I remember correctly it was something about ensuring a more accurate reading or some such, as being next to the thermostat messed with it on occasion apparently.

I've also heard the location at the rear of the block drives up the patience requirement a bit, and of course makes the "thermo/ECT combo job" a bit more painful than it should be. Speaking of which, if you're looking to change your ECT and you have any questionability on the thermostat, since you'll already have the coolant drained anyway it wouldn't hurt to swap if you feel like it and can afford it. If your thermostat is still working good, you can skip changing it out or save the old one as an emergency part.

 

[djthumper]

Check out his name/above his picture!

That is what I was talking about...

 

[Sparky]

I find it interesting in that diagram how they show the new 06+ sensor location, but show an older 02-05 head on that engine lol (look at the coil packs).

 

[sunliner]

not entirely sure if it needs changing. my reasoning for thinking it might:
my dash gauge always reads one tick left of 210.
on a 2.5 hour highway trip last week (Lake City to Orlando, FL) the gauge planted itself right at 210 maybe on the right side of that thick hash mark of 210. Never went any higher, even when we had to stop in traffic for 10+ minutes. It was in the 90's outside.
Made it back home and just around town it stays about one tick left of 210, maybe a little closer at times. I plugged in my scan tool and the temp it shows is about 188 deg, absolute highest was 192 deg.
probably just my obsessive nature acting up , but that one tick bothered me; and even knowing that the dash gauge is approximate, the fact that the scanner says it's averaging in the high 180's was bugging me too. I've never bothered with the scanner before for checking temps though, so this could be the way the truck has always run.

 

[BlazingTrails]

I put a new thermostat in mine and ect sensor. Mine gauge floats between 150-210. I have concluded that the stepper motor for the temp gauge is bad.

 

[djthumper]

The thermostat should fix it.I had the same issue with mine and didn't replace the ECT.

 

[BlazingTrails]

The thermostat should fix it.I had the same issue with mine and didn't replace the ECT.

You can't know that for sure thump. In my case I was getting a code for low ect readings. I replaced my thermostat and ect sensor as a set, and my gauge still acts up. Temp is normal and no codes. So I am 99% sure my stepper motor is bad. If he isn't getting a code, or if his ect sensor isn't reading correctly it won't fix it. The only way to know for sure is to check it with a thermometer outside the system. There are always tests to know what the problem is, so you don't waste money on parts you don't need IMO

 

[djthumper]

You can't know that for sure thump. In my case I was getting a code for low ect readings. I replaced my thermostat and ect sensor as a set, and my gauge still acts up. Temp is normal and no codes. So I am 99% sure my stepper motor is bad. If he isn't getting a code, or if his ect sensor isn't reading correctly it won't fix it. The only way to know for sure is to check it with a thermometer outside the system. There are always tests to know what the problem is, so you don't waste money on parts you don't need IMO

Yours is a stepper motor... The OP is just the thermostat with the info he gave later in post 18. The ECT only sends a signal to the PCM to determine what it wants to send to the gauge. Unless I get a flakey reading while scanning I will always look to the thermostat on this platform...

 

[BlazingTrails]

Yours is a stepper motor... The OP is just the thermostat with the info he gave later in post 18. The ECT only sends a signal to the PCM to determine what it wants to send to the gauge. Unless I get a flakey reading while scanning I will always look to the thermostat on this platform...

I've read all the post, I still think his problem is the ect sensor. I don't think it is the thermostat at all.

 

[Midnyteryder196]

With the temp at max of 192.. I would say tstat.. Wen I had issue with ect after my tstat change it still read higher than 192.. Right up where it should run (200-206).. It would fluctuate though..

On my torque I could watch it go from 185 to 187 to 192 then to 186 to 195 n back to 185.. So I knew it was ect then..

To the op.. Change the tstat, then keep close eye on temps with scan gauge.. If it is steady you will be fine, but if its fluctuating, then change the ect

 

[IllogicTC]

Between the two parts, is the thermostat the cheaper one anyway? And way less time-consuming. If it turns out being the ECT, since you'll have fresh Dex in there from doing the thermostat recover as much as you can for reuse.

 

[BlazingTrails]

Where is he getting his temp reading from guys? Pcm/scanner? Where does the pcm get it's info? Ect sensor. I work with inputs/outputs, controllers, and sensors for a living. And much more complicated systems than just vehicles. I am not trying to argue, just giving my opinion and I respect yours just as I would expect you to respect mine. I may be new to this site, but not new to troubleshooting. Bottom line is I just want to see the guy fix his car without buying parts he does not need. It may be the thermostat? I guess we will find out....

 

[IllogicTC]

Either way involves draining the cooling system. A compromise would be removing the thermostat and checking if it's jammed in the open position. If yes, replace. If no, ECT. If yes and results persist, it was both parts.

 

[sunliner]

I already have both parts (with a chevy, it's never a bad idea to have this stuff on hand...) but elected to reattach the alternator,enjoy my Saturday and maybe do this next week.

I'm still figuring stuff out so I'm just asking...if the tstat was stuck open, wouldn't it be slow to warm up to, but eventually reach operating temp, especially on a long highway trip?
If it was stuck closed, it would be overheating.

 

[Mounce]

Mine is stuck open (i assume, because I got a code for it) and it hardly ever reaches operating temp (210 on the gauge) even on a 400 mile drive to Kentucky. It went up to 210 the other day during normal distance driving and I thought it was closing but no, next day, tick or two to the left.

 

[dmanns67]

Mine is stuck open (i assume, because I got a code for it) and it hardly ever reaches operating temp (210 on the gauge) even on a 400 mile drive to Kentucky. It went up to 210 the other day during normal distance driving and I thought it was closing but no, next day, tick or two to the left.

You are risking other issues by not fixing your t-stat. I got my Stant t-stat from rock auto for less than $20. I also got the AC Delco ECT sensor for around the same price.

Mine would never get above 185º even on the highway or long road trips. When I would get on the accelerator, it would drop to around 165º.

 

[IllogicTC]

You are risking other issues by not fixing your t-stat. I got my Stant t-stat from roack auto for less than $20. I also got the AC Delco ECT sensor for around the same price.

Mine would never get above 185º even on the highway or long road trips. When I would get on the accelerator, it would drop to around 165º.

True. Less than $20 fixes potential issues with carbon buildup, catalytic converter clogging, and gas mileage. Also gets the heater working nicely in the winter.

 

[Mounce]

Yeah I just haven't got around to it. But stant from rockauto is good? I read somewhere that some brand isn't shaped right.

 

[BlazingTrails]

I would recommend this thermostat. I personally have not had good luck with stant. And for Christs sake don't buy O'reiley's brand.

http://m.ebay.com/itm/331080968487?nav=SEARCH

 

[dmanns67]

Yeah I just haven't got around to it. But stant from rockauto is good? I read somewhere that some brand isn't shaped right.

Not sure. Looked just like the OE one I took out and fit just the same. I went with Stant because rock auto did not offer AC Delco that I could find.

Make sure you get the 5% off rock auto code. Google "rockauto.com coupon code" and something should come up.

If the funds support, might as well pick up the ECT sensor as well since it is right there, unless you have the 06-09 then it is on the passenger side toward the firewall and it is a huge PITA.

 

[Mounce]

We changed the ect already when we first got the code either thinking that would fix it or maybe it actually had a code for it, I don't remember. The ect under the alternator is also a pita, and the hood support is right in the way.

 

[dmanns67]

We changed the ect already when we first got the code either thinking that would fix it or maybe it actually had a code for it, I don't remember. The ect under the alternator is also a pita, and the hood support is right in the way.

Gotcha. From what I have read, majority of the time the issue is with the t-stat, but went ahead and did both since the part was so cheap.

Another reason why owners should upgrade to RedLine Tuning hood struts, get rid of the hood prop. Great investment IMO.

 

[Mounce]

Lol yeah it'd be nice if GM would've put the spring loaded type like what's on Silverados on there. When my bro and I changed the ect we took turns holding the hood up while one of us worked on getting stuff out. I remember the bottom alt bolt was a huge pita.

 

[The_Roadie]

RedLine struts was my very first mod. Been loving them ever since!

 

[IllogicTC]

Gotcha. From what I have read, majority of the time the issue is with the t-stat, but went ahead and did both since the part was so cheap.

Another reason why owners should upgrade to RedLine Tuning hood struts, get rid of the hood prop. Great investment IMO.

You have me interested.

 

[dmanns67]

You have me interested.

Price ranges from $70-$120 based on finish/material. I went with the $70 kit. Very easy install. Masking tap, drill, and rivet gun. Rivets are provided with kit. They provide detailed install instructions as well.

http://www.redlinetuning.com/QL-CHEVY-TRAILBLAZER-02+.html

 

[IllogicTC]

Price ranges from $70-$120 based on finish/material. I went with the $70 kit. Very easy install. Masking tap, drill, and rivet gun. Rivets are provided with kit. They provide detailed install instructions as well.

http://www.redlinetuning.com/QL-CHEVY-TRAILBLAZER-02+.html

Great link. 2 year warranty for even the basic model isn't too shabby, either. Looks like the PLUS kit switches to the ELITE brackets, while the ELITE is fairly different (and double the warranty). May have me reconsidering my stock status.


So OP, any news on what's going on?