Hello, new to the forum and seeking a bit of help...

[Davis1979]

First off hello fellow owners...

I have a couple issues that I can't seem to sort out.

1. I bought my 2002 trailblazer a couple months ago and second day of owning it the ses light came on, saying the engine is too cold.. Had the dealer install a new thermostat and temp sensor, light went off and temp got hotter but not all the way to 210, I hear this is an issue but I have had dealer install everything new for the cooling system and nothing has changed.

Dealer installed parts include, thermostat, temp sensor, fan clutch, water pump and full system flush... Still will not get to 210, it is two to three ticks away. Been driving the truck 30-40 miles on highway one way to work ever since no ses light, but just worries me since I have read this is a bad thing on this vehicle... Dealer doesn't seem to worried about it.

2. I have a miss during throttle, when accelerating up to speed the truck just stumbles on itself and I can clearly hear a miss and can also feel it in the performance of the truck. I have installed a new fuel filter, air filter, ac deco iridium plugs, and two brand new coils due to there being tons of rust of the points of the old coils. All other coils check out at idle but haven't had help to check with a torq idle. Will do ASAP but just wondering if there is any ideas other than that???

 

[Robbabob]

Welcome to the jungle! ermm, Forum!

Someone will be along shortly to help you.

 

[BoldAdventure]

Welcome to the forum. Please learn to use the search button.

 

[NewfieEnvoy]

Welcome to the Nation.

For temp you need a scan tool and do not trust the dash gauge. If you have an Android phone or table download Torque app and get a cheap OBD2 bluetooth adapter, lots of threads on here about them. My temp never reaches 210, hovers around 192-195. A little cool but I live in a cool climate. There's threads on here describing the correct operation of the thermostat from cold start to highway run, while viewing the temp on a scan tool you can then tell if the thermo is sticking open.

Have you cleaned the throttle body and left the battery cable off for 20-30mins. Its a routine cleaning (usually every year for members) that is very necessary to smooth idle and good throttle response. Not saying that's casuing your issue but you should take care of that first if it hasn't been done in a while. There's an article describing procedure.

 

[Robbabob]

video:
http://gmtnation.com/f40/superstars-how-videos-thread-229/#post10411

article:
GMTNation - How to Clean an 4.2 Inline 6 Throttle Body

 

[CaptainXL]

First off hello fellow owners...

I have a couple issues that I can't seem to sort out.

1. I bought my 2002 trailblazer a couple months ago and second day of owning it the ses light came on, saying the engine is too cold.. Had the dealer install a new thermostat and temp sensor, light went off and temp got hotter but not all the way to 210, I hear this is an issue but I have had dealer install everything new for the cooling system and nothing has changed.

Dealer installed parts include, thermostat, temp sensor, fan clutch, water pump and full system flush... Still will not get to 210, it is two to three ticks away. Been driving the truck 30-40 miles on highway one way to work ever since no ses light, but just worries me since I have read this is a bad thing on this vehicle... Dealer doesn't seem to worried about it.

If your worried about it take it back and explain to them the repair appears to be incomplete. Shouldn't cost you a thing to have them check it out.

2. I have a miss during throttle, when accelerating up to speed the truck just stumbles on itself and I can clearly hear a miss and can also feel it in the performance of the truck. I have installed a new fuel filter, air filter, ac deco iridium plugs, and two brand new coils due to there being tons of rust of the points of the old coils. All other coils check out at idle but haven't had help to check with a torq idle. Will do ASAP but just wondering if there is any ideas other than that???

If your ignition system is in order I would start looking into compression issues or clogged fuel injectors or gummed up valves. A strict regimen of 87 octane top tier fuel and Techron Concentrate Plus or BG 44K should clear this up. Could take a couple months driving depending on how bad the injectors are and how much you drive. You might want to have a shop or dealer do a fuel rail clean considering the vehicle appears to be neglected. #6 cylinder and injector is prone to clogging and carbon buildup due to the fact it is last in line on the fuel rail and pressures drop off especially if the fuel pressure or volume is not right. It was a good idea for you to change the fuel filter.

Also, it's been covered extensively before but on pre-2005 the fuel pressure regulator can sometimes malfunction and leak fuel into the intake. You should get that checked as a preventative maintenance item as well along with checking engine vacuum and cleaning of the throttle body as explained previously.

 

[Mark20]

Welcome to the Nation!

As you will learn here, the temperature gauge lies. Normal - not under any particularly heavy load - has the gauge straight up or one tick to the right. I have a Scan Gauge which reads directly from the ODB port. I usually run 195 - 198 F according to it. If the temperature is below straight up, it could e the seller motor itself.

 

[Robbabob]

Welcome to the Nation!

As you will learn here, the temperature gauge lies. Normal - not under any particularly heavy load - has the gauge straight up or one tick to the right. I have a Scan Gauge which reads directly from the ODB port. I usually run 195 - 198 F according to it. If the temperature is below straight up, it could e the seller motor itself.

Our gauge runs between vertical and one click left. I know to change the stat if it gets to 2 clicks left.

Side note: Guy we purchased the TB from, knowing we were lined up to purchase the truck, changed the stat because he knew it needed to be done. How's that for nice?!?!? Could have just warned us to do it and went about his business.

 

[CaptainXL]

Our gauge runs between vertical and one click left. I know to change the stat if it gets to 2 clicks left.

Um, exactly how many times have you changed the tstat? You make it sound like it's changed every 10K miles. lol

Also, as Roadie has said many times before...there really isn't any reason to change the tstat until the check engine light comes on or a scan tool shows the coolant temp to be near the threshold. In our case it's right around 185F. If the light does come on and you have a P0128 then of course change it asap. Just remember that a scan tool and the list of scan tool parameters I have listed here so many times before with tell you much more than just starring at the dummy gauge which we all know is inaccurate at best.

Side note: Guy we purchased the TB from, knowing we were lined up to purchase the truck, changed the stat because he knew it needed to be done. How's that for nice?!?!? Could have just warned us to do it and went about his business.

So in retrospect (and being totally respectful) that's not the brightest thing you did right? Purchase a vehicle with the check engine light on?

There are two pet peeves I have when purchasing a trailblazer/envoy.

1. Has it ever overheated during it's lifetime? This can result in low compression.

2. Is the check engine light on for P0128? If it is on then for how long? The catalytic converter might be toast.

 

[Davis1979]

The light was not on when I bought it... The second day of ownership the light came on...

Thank you for all the great advice, I have a few things I can try now! Ill post my findings as soon as I am done...

As for learning to use the search function I understand how to use it... I didnt find anyone with ALL of the issues I am having that a new thermostat, temp sensor, fan clutch, rad flush, water pump didnt fix (which I have already tried). I have been searching on here and another trailblazer forum for answers for three months now with no luck.

I found a couple blutooth scan tools on ebay and amazon but all I see only work for android devices, all I have is apple products and I am not sure if they will work on Ipads, or Iphones... Any luck with this answer?

 

[The_Roadie]

The light was not on when I bought it... The second day of ownership the light came on...

Classic sneaky-ass seller trick. Depending on state law you may have some recourse.

 

[Wooluf1952]

Welcome and good luck

In case you haven't heard:
http://gmtnation.com/f5/welcome-gmtnation-com-heres-story-226/

 

[jonbo2002]

Classic sneaky-ass seller trick. Depending on state law you may have some recourse.

exactly!!! disconnect the battery cable to clear the codes then it becomes the new owners problem!!! just shaddy behavior too many people trying to get over on everyone else. what ever happened to helping out your fellow man?

 

[Mypetropig]

You have paid the dealer a lot of money for these repairs I'm sure. Since they tell you not to worry about it, I would take it back there and ask them to show you the data on a scan tool while connected to your truck. Tell them that's what you want so they dont show you a freeze frame of someone else's truck. If the data stream shows 192-200 you are good, probably just a stepper motor acting up.
As for the misfire go back and double check the coil packs and make sure the are seated good. Its awfully easy for them to not seat properly.

 

[Robbabob]

I assume both of these are for me and the other comments for the OP.

Um, exactly how many times have you changed the tstat? You make it sound like it's changed every 10K miles. lol

Far as I know, it's only been changed the one time.

So in retrospect (and being totally respectful) that's not the brightest thing you did right? Purchase a vehicle with the check engine light on?

No disrespect taken.... lol No CEL for our purchase, he just knew it wasn't running hot enough and didn't want us to be burdened. Test drives were perfect. Our only question was the "hunkering down" when shifting into 4Lo. Brought that question to the forum and it was cleared up.

 

[Robbabob]

exactly!!! disconnect the battery cable to clear the codes then it becomes the new owners problem!!! just shaddy behavior too many people trying to get over on everyone else. what ever happened to helping out your fellow man?

Well, we did have a helping hand guy with our purchase... guy changed the tstat knowing it was running a little cooler than it should. He didn't have to, he just did it.