Ngk plugs or ac delco ????? For a 05 trailblazer

[Malo]

So little by little am starting to fix and change shit on my 05 trailblazer my next thing in line is to clean the Throttle Body and change my plugs i have been searching on line for the best ones and so far i know chevy uses ac delco as oem ones but i have also heard about NGK been better any suggestions my truck is a 4.2 with 125k miles ?, also i feel like my truck sounds like a diesel is so loud not only at cold starts but the whole time is on i actually hear like a little knocking but im a car illiterate so i might be wrong here is a video of my engine after is warm https://www.youtube.com/watch?v=y1bmqWsYnKM and here are some pics of my throttle body

 

[Envoy_04]

Whatever you do, only use ACDelco 41-103 spark plugs in your 4.2 liter engine. Other types can cause the vehicle to run poorly and throw codes and turn on the service engine light in the dash. Since you're at 125K you might as well replace the O2 sensor in the manifold too, I say it should be done at 100K along with the plugs. (will be called position 1 or "upstream" sensor) - ACDelco is a good brand to use here as well.

As for the throttle body, GMTNation - How to Clean an 4.2 Inline 6 Throttle Body - This is where you can read all about how to remove and clean your TB the right way. Pull fuses number 10 and 28 in the fuse box under the hood instead of unhooking the battery. Just remember to plug them back in when you're done.

That engine is noisy, but it could be several things making the noise. Run a search for Seafoam cleaning on here and some threads should come up about how to run Seafoam through your engine - that may help and it may not.

 

[triz]

Your on the right path with cleaning the throttle body. You can try cleaning the CPAS out and see if quiets down. A little quality synthetic Amsoil XL oil change (better cold start properties, better MPG's) Far as plugs go NGKs are good but these trucks tend to like the OEM. At that mileage you should have also changed your differential fluids, transfer case if it's 4x4, and transmission filter with new fluid.

 

[Malo]

Thanks guys is changing the transfer case some thing I can do or should I take it to a mechanic, same thing with the 02 sensor and is changing the transmission fluid and filter the same as having a transmission flush.

 

[Envoy_04]

This all depends on how handy you are with a wrench.

The T-case fluid change isn't all that hard - a search should turn up some threads on the exact procedure, I don't have all that info handy right at the moment.

The O2 sensor isn't too bad at all - you have to rent the special sockets for it from AutoZone or Advance, but then you return them and get your money back. Best way to do this is drive the vehicle and get it up to temp. Shut it down and wait a few minutes, then get in there and being careful not to burn yourself unhook and remove the old sensor from the manifold. It will be tight and might give you a little trouble - be gentle however because if you strip the threads you'll be looking at a possible manifold replacement. If you buy an ACDelco replacement sensor it'll come with the threads pre-treated with an anti-sieze compound, just screw it in til it's tight (don't actually know a torque for this, but good judgment will tell you when it's tight) and hook the wire up and you're done.

Changing the transmission fluid and filter (dropping the pan method) isn't the same thing as a flush. Dropping the pan and changing the fluid in it and the filter only changes part of the fluid in the transmission - a flush, well, flushes out all of the old fluid, on top of dropping the pan and changing the filter. Either of these is a little more involved than the T-case fluid or the O2 sensor, and unless you're comfortable with a big mess from the fluid, getting dirty, and with getting the filter, seal, and pan all put in just the right way, then you would probably be better off to have a reputable and trusted mechanic or shop do this.

 

[glfredrick]

Whatever you do, only use ACDelco 41-103 spark plugs in your 4.2 liter engine. Other types can cause the vehicle to run poorly and throw codes and turn on the service engine light in the dash.

I completely agree! For whatever reason, the TB only likes factory spark plugs! On my third set for my 03 model with 150,000+ miles.

 

[Malo]

Has any of you guys ever used bosh brand name o2 sensor for some reason my local autozone doesn't carry acdelco they only have NGO,bosh or denso?

 

[djthumper]

Has any of you guys ever used bosh brand name o2 sensor for some reason my local autozone doesn't carry acdelco they only have NGO,bosh or denso?

Go to another chain or order from online. AC Delco is what your truck will not chew up and spit out at you or at least it seems that way.

 

[Playsinsnow]

Go to another chain or order from online. AC Delco is what your truck will not chew up and spit out at you or at least it seems that way.

ACDelco 41-103. Buy 'em where they got 'em.

Is Advanced in Mchenry still open? They carry ACDelco

 

[kickass audio]

I know everyone says to use ac delco plugs but I have champion iridium plugs in mine and they work perfect. I have had them in for 26k miles so far with 0 problems.

For getting that O2 sensor off and replaced I prefer to get the oxy acetylene torch out and warming it up a little, I think even a propane torch would work too but its hard getting that down there than the oxy acetylene torch on a low setting. Just heat it up where it goes in the manifold and I like giving it a few squirts of water when its nice and hot to try and get the rust out of the threads and then I heat it up a little more and take it off with a crescent wrench. I only use the O2 socket for putting the new ones on. Just my own experience with what I do to change those stubborn things.

Your throttle body doesn't look bad on the front but the back side is where it gets caked with crud. I clean mine 2 times a year and another thing someone will complain about is that I don't pull the fuses or battery after its done and again 0 problems with my performance or anything but then again mine is cleaned so often it doesn't have a chance to gum up like my original one did when it had a bad throttle position sensor in it. The previous owner never cleaned it and it was pure black on the back side and on the rim of the TB.

 

[Juicy K]

I would stick with the AC Delco 41-103's (I know im too cheap to find out I have to buy another set of plugs a week later).

Like has been said if its 4x4 get that Transfer Case fluid changed (Make sure to use AutoTrak II fluid) it should be changed every 50k miles.

Differential fluids ( I change them when I do the Transfer Case ) 75-90 Synthetic Gear Oil

Search " Clean CPAS " here on the forum, the writeup was done by Voymom it helped clean up the Idle in my Fathers 05 Trailblazer. It looks like more surgery than it really is, the worst part is putting the accessory belt back on.

 

[glfredrick]

ACDelco 41-103. Buy 'em where they got 'em.

Is Advanced in Mchenry still open? They carry ACDelco

ACDelco 41-103 Professional Iridium Spark Plug, Pack of 1 : Amazon.com : Automotive

Bosch is ok for O2 sensor.

 

[triz]

Has any of you guys ever used bosh brand name o2 sensor for some reason my local autozone doesn't carry acdelco they only have NGO,bosh or denso?

For the o2 sensor use the denso. That is what came on Mine from the factory.

 

[dla442]

Delco delco delco. For plugs and o2 sensors. Changing trans case fluid ez work. Get a fill adapter for the bottle( which screws on to the delco purchased fluid) and it squeezes,in real nice. I do my xfer case every 50k. Two quarts to save $$$ in the long run.

Use anything else but a delco o2 and you will notice poor performance. The NGK or denso don't cycle as fast as the delco. Yes one of the two prob makes delco but your paying the same price anyway, why stray? Read roadies posts on this issue.

 

[dla442]

I know everyone says to use ac delco plugs but I have champion iridium plugs in mine and they work perfect. I have had them in for 26k miles so far with 0 problems.

For getting that O2 sensor off and replaced I prefer to get the oxy acetylene torch out and warming it up a little, I think even a propane torch would work too but its hard getting that down there than the oxy acetylene torch on a low setting. Just heat it up where it goes in the manifold and I like giving it a few squirts of water when its nice and hot to try and get the rust out of the threads and then I heat it up a little more and take it off with a crescent wrench. I only use the O2 socket for putting the new ones on. Just my own experience with what I do to change those stubborn things.

Your throttle body doesn't look bad on the front but the back side is where it gets caked with crud. I clean mine 2 times a year and another thing someone will complain about is that I don't pull the fuses or battery after its done and again 0 problems with my performance or anything but then again mine is cleaned so often it doesn't have a chance to gum up like my original one did when it had a bad throttle position sensor in it. The previous owner never cleaned it and it was pure black on the back side and on the rim of the TB.

I just ran the engine for about 3-4 minutes to get the manifold and sensor warmed up. Came out ez but had to chase the threads in manifold to get new sensor to thread. Your money if you don't make sure the threads on manifold are good before you put in new sensor.

 

[The_Roadie]

Has any of you guys ever used bosh brand name o2 sensor for some reason my local autozone doesn't carry acdelco they only have NGO,bosh or denso?

Bosch have been reported to work fine, and give good data, but the attribute of the sensor that sometimes (not always) throws a code is the HEATER current is on the hairy edge of a threshold level built into the PCM. The Bosch seem to be near (or just over) the threshold, and if the PCM sees its expected measurement is exceeded, it will throw a code. This can cause you to fail an emissions test. But the functional performance of the sensor side of the sensor is fine.

Go to another chain or order from online. AC Delco is what your truck will not chew up and spit out at you or at least it seems that way.

AC Delco is an O2 sensor whose heater performance seems to be farther away from the failure threshold and members haven't reported heater codes at all, compared to the Bosch.

I know everyone says to use ac delco plugs but I have champion iridium plugs in mine and they work perfect. I have had them in for 26k miles so far with 0 problems....

Non Delco plugs sometimes work out of the box with no issues. What they don't seem to do is to go all the way to 100K miles without starting intermittent erratic misfires that throw codes of the form P030X. Some alternate brands work for only 5K miles, then throw codes. Some go to 75K. Some might go to 100K. Everybody's experience (and engine and fuel, etc) can be slightly different. The universal recommendation for AC Delco 41-103 plugs comes from the volunteers here who are trying to help owners avoid issues down the road.

ACDelco 41-103 Professional Iridium Spark Plug, Pack of 1 : Amazon.com : Automotive

Bosch is ok for O2 sensor.

As noted, and I've read hundreds of thousands of posts over the years - Bosch is one brand that has caused heater current faults. Since there's always slight variations in manufacturing process, some Bosch might work fine for 100K for some owners. But some have thrown that code, and I don't feel it's prudent to recommend Bosch, even though it's a fine brand. If you have put one in, I wouldn't change it. Until and unless it throws a code.

For the o2 sensor use the denso. That is what came on Mine from the factory.

Densos have been reported to not throw codes as often as the Bosch. Another quality brand.

Use anything else but a delco o2 and you will notice poor performance. The NGK or denso don't cycle as fast as the delco.

Somehow I don't remember reading any posts about this from somebody with first-hand experience and a suitable scan tool. Got a link so I can do more research?

 

[kickass audio]

I never had problems with my envoy putting a new one in for the threads. Only on my old car did I have problems where I had to chase the threads but other than that I have done them on mine and my dads truck and had 0 problems just unbolting it and putting it back in.