Spark Plug Change in a Truck--How Hard Can it Be? Update#2

[BFL13]

Update-fuel filter only- 26 Feb 15.
Update 2- 28 Feb

The 2003 Chev 2500HD 6.0 Gasser we got new with now 150,000km on it is getting cranky going up hills while towing. Lots of snappy bangs and the engine light comes on flashing till we get to the top and ease off.

Chev dealer shop guy said it was the fuel/air mixture sensor being dirty and they cleaned it off some as a fix. The fix worked for a while but not for long. He said I really needed new plugs and wires and maybe a new fuel filter.

So first question, could it all be the fuel filter's fault--that is easy to take care of. (supposed to swap that every so often but it seems I never have, so that is not an option now. Will do)

Next thing is a couple shops I went to both say it is a two- hour job to change the plugs so labour is $200! The cost of the plugs seems ok although that is confusing.

GM I think uses platinum tip but another place says their replacement for that is an iridium tip. But a third shop says there are different qualities of iridiums and platinums so how can you know what is equivalent to what? Is a $10 (vs a $20) iridium as good as a $10 platinum?

The wires come in two forms where we have the "square" coils and some have the "round" ones. Whatever. I am scared to touch them. The GM shop said I might not need wires. How can you tell if you do?

Years ago I just bought plugs and wires and changed them myself. Got the spark plug piece in my tool box. (3/4 inch?) This looks way too scary with those coil things there, but is it really? I don't mind the price of the plugs and wire kit, but that labour cost is crazy if I can just do it like before in simpler times. I don't care if it takes me all day instead of two hours! 🙂

So, how hard can it be? Or do I just pay up and not have to worry about it for another ten years or so?

Thanks.

[BFL13]

So the old plugs were these which are their platinum "series" but are "iridium/platinum" too.

http://www.stylintrucks.com/parts/ngk_laser_platinum_spark_plug_-_pztr5a-15/23870/ngkng7862-.aspx

The new plug is "iridium enhanced" but also "platinum" Not too confusing! Anyway the truck runs on either plug whatever they are made of.

http://www.amazon.ca/Autolite-XP5245-Iridium-Spark-Plug/dp/B000ET5TFI

[Sport45]

Glad you got this behind you. Keep enjoying it!

[BFL13]

Update #2

I got the plugs and wires swapped.

Somebody said he was able to give them another last squeeze turn and he called that good, without using a torque wrench, but I just got the same turning feel clockwise until it hit the wall, no extra squeeze possible--I didn't try really hard though in case I broke something. So the torque wrench didn't get to play, the plugs were as far as they would go.

Any comments on that? Thanks.

The old OEM plug is an ACDelco branded NGK PZTR5A 15 and my new plug the auto store says is the right one, is Autolite Iridium XP5245

The old ones I have out all are dark in the gap but clean and dry. I was told the new ones are pre-gapped to 4 but it doesn't say so on the box.

Somebody said the originals would have been gapped to 6 and later GM changed that spec to 4, so I wonder about that where the new one supposedly at 4 looks the same gap beside the old one. I know not to gap the iridiums.

I am grateful somebody earlier said to save the heat shields so I was not caught by surprise there.

The wire kit came in handy, needed or not for the swap, since I did pull apart one old wire getting it off.

Took it for a spin, ran smoothly, stomped it into passing gear and it revved up like it should, no snaps, no engine light. It all seems a little more lively but hard to tell. Anyway got it done thanks to the help here.

So the garage wanted $400 for that and it cost me $160 instead 🙂

[BFL13]

Sport45 wrote:
You don't have a carburetor. The carb cleaner suggested is for cleaning your throttle body. A very good idea. To clean the TB on out Envoy 4.2L I remove it first. I can do a better job of cleaning it and don't have to worry if the cleaner is "sensor safe" or not. In 125,000 miles I've only had it off twice.

Ok I get it now. Maybe that's what they did when they said they cleaned "it" I'll find out what that is about.

I am wondering if it will still act up after I change the plugs and wires because the sensor is now dirty again since they cleaned it.

The truck sure runs better with the new fuel filter. I had no idea it wasn't running so well before. It must creep up on you and you get used to little hesitations (now mostly gone) when at idle etc. Maybe if I had kept an eye on my gas mileage I would have noticed it was getting worse, no idea. Anyway, "smooth running" has gone from "good" to "real good", so with the new plugs and wires as well, we should get to "really good". 🙂

Got to say this truck is way better than any car we have ever had for how little work it needs on it for the miles on it. Course it cost a bundle new, but after twelve years that puts us ahead in comparison. Too late to apply that lesson now! You can't turn the clock back. 😞

[Sport45]

You don't have a carburetor. The carb cleaner suggested is for cleaning your throttle body. A very good idea. To clean the TB on out Envoy 4.2L I remove it first. I can do a better job of cleaning it and don't have to worry if the cleaner is "sensor safe" or not. In 125,000 miles I've only had it off twice.

[BFL13]

Bamaman1 wrote:
BFL13: You seem like you have more than the limited skills to change LS engine plugs.

You should just change the spark plugs and take carb. cleaner and clean the throttle body butterfly and throat while your under the hood.

Drive your vehicle and see how it runs. If the wires and/or a coil are not good, you'll get a trouble code that tells you which cylinder needs attention.

Thanks. I didn't know I even have a carb! I know I have injectors and an air intake with a filter for that, and some sort of sensor that does air/fuel mix, because it was dirty and they cleaned it in hopes that it would not need replacing.

I did have codes showing that air/fuel mix sensor was not right before they cleaned it. All way too modern for my tiny brain! I was ok with a 1973 Datsun truck back in the day. Oh well. I think I should still be able to change a spark plug though. How much can they make that too complicated nowadays? I know, there is no
limit. 😞

I am going to give it a try thanks to what I have learned so far. The auto parts shop I like says the OEMs are iridium despite the story they were platinum. They have lasted 150,000kms (about 94K miles)if that is a clue. Don't care, am getting the iridiums as replacements like the auto store says and the wire kit and we will see how it all goes.

[Bamaman11]

BFL13: You seem like you have more than the limited skills to change LS engine plugs.

You should just change the spark plugs and take carb. cleaner and clean the throttle body butterfly and throat while your under the hood.

Drive your vehicle and see how it runs. If the wires and/or a coil are not good, you'll get a trouble code that tells you which cylinder needs attention.

[Bamaman11]

Turtle n Peeps wrote:
No big deal. My BMW has lifetime ATF in the tranny. :E

I hate to be the bearer of bad news, but the ZF transmissions used in BMW's have a high incidence of failure. My Jaguar convertible also has the same ZF. There is no dipstick tube to add tranny fluid through.

ZF's really need the automatic transmission fluid changed every 60K miles or so. They require special fluids and the filters and pan gaskets are hard to find locally.

A special engine scanner tells the technician when the transmission is the proper temperature for topping off the fluids. It's added to a plug in the top/side of the transmission with a pump until it overflows. A laser thermometer can also be used on the tranny pan.

It's not something that an amateur cannot do, but they're bad to breakoff the pan bolts.

[BenK]

Platinum, iridium, etc are not particularly good 'performance' plugs...just good
for 100,000 miles

The point is a good idea and plays on the corona effect

Key is their thermal rejection management and I like copper cores for that. Harder
to find these days...also love cut-back plugs and make my own. Last time checked
NGK has them as a custom order and IIRC $200/each with a minimum order

It is best to use OEM

Coils at the plugs has a shorter high voltage run over a single coil and those
coils can be fired with solid state semi conductors. Less silicone iron, so higher
raise time for multiple sparks...if the computer is capable (AKA PWM)

Anti-seize can get you into more trouble with tapered seat and as noted over
torque way easy...better leave that to those who know HOW2...sorry for that one

Careful on some FORD engines. They have a very, very long snout and they get
built up deposits to require special procedures...else they might break in half

[dodge_guy]

And no fancy plugs, just use what the manuf uses!

[BFL13]

I have changed plugs years ago lots of times but not lately so I was confused about the individual coils for instance.

I will be getting iridiums and the wiring kit if I decide to try it myself. I would do just one first and see how that goes.

All tips and warnings have been noted and appreciated.

[gmw_photos]

Some have mentioned using anti-seize on spark plug threads. One should be careful with this idea and defer to the spark plug manufacturer instructions. NGK for instance advises against this practice. Be aware also that using anti-seize will change the torque value and could lead to stripping the threads.

[zogg]

I'm a pretty good shade tree mechanic, and I can't tell you how many times I've had neighbors, relatives and friends call and ask for help after they've tried some auto repair that was over their capability.

With the questions you are asking, I agree that you are better off going to a shop and paying the price....it's a once in a 150k expense. A shop can replace the plugs, check to see if you need wires, get the correct wires, etc etc etc etc.

I once had a neighbor who had his ford range towed into the dealership because he stripped the threads on the oil filter plate....he was trying to change the oil for the first time in his life....he had watched a you tube video.

Would you teach your kids how to drive by letting them watch videos and then turning them loose with your car?????

There is nothing wrong with knowing your limitations.....otherwise the cost of repairs to fix your mistakes could outweigh the cost of spark plugs....check out the cost of repairing a stripped spark plug hole as a simple example.

Not being mean here, just trying to save you a bunch of money and great burn.......

[dodge_guy]

Get ready to replace the Cat if you continue to drive it with the severe miss-fire! All standard plugs should be replaced areound 30-50k miles. platinums around 80k, yes I know they say 100k intervals, but I`ve seen electrodes worn away at 70k.

Preventive maint.