4.8L Spark Plug Analysis (Pictures)

[Lsxtrucker]

While I'm waiting on delivery man to bring my 3/8" drive torque wrench replacement I decided to take a shot of each plug in hopes of any input from you LS pros. These original iridium plugs were pulled at 150k in my DD, fresh 41-962's going in tomorrow with a new set of ACD wires. 

[Colossus]

Should have been replaced at 70,000 miles.  Well worn out. 

[Lsxtrucker]

I just bought her a week ago. I realize it's long overdue. Good thing she's in caring hands now. 

[Colossus]

They are good engines.  Congrats!   I'd go ahead and have a top engine clean done, run some BG EPR right before you do your next oil change (put it in 10 min prior to your oil change and drive around, then change oil) Put new plug wires on as well, Drain and fill the tranny fluid (not sure I'd flush it at this point if it wasn't serviced previously) and do a good coolant flush as well.  And power steering fluid.  Front and rear diff and transfer case if it's a 4x4, otherwise rear diff.. and you'll be good. 

[Lsxtrucker]

Typo

[Grumpy Bear]

https://www.strappe.com/plugs.html

 

Spark plug reading has never been well understood. Gordon Jennings wrote this article in 1977 for Cycle World and it IS the gold standard for tuning. Maybe Champion still sells the tool for reading them. Even people that should know and don't. 

 

That said you can still learn a lot about the general condition of  your motor by the condition of the plugs over long service like yours. 

 

 

Consider it before you condemn it as 'out dated'. 

[Lsxtrucker]

2 hours ago, Colossus said:

They are good engines.  Congrats!   I'd go ahead and have a top engine clean done, run some BG EPR right before you do your next oil change (put it in 10 min prior to your oil change and drive around, then change oil) Put new plug wires on as well, Drain and fill the tranny fluid (not sure I'd flush it at this point if it wasn't serviced previously) and do a good coolant flush as well.  And power steering fluid.  Front and rear diff and transfer case if it's a 4x4, otherwise rear diff.. and you'll be good. 

Hey thanks! That engine clean service you speak of...Is that done at the GM dealer? I ordered new OEM plugs and wires. Just did a fresh change with Delco Dexos full synthetic. I've got three quarts of 75-90 Mobil 1 for the rear diff and a new gasket for it too.  As for draining and filling the tranny fluid, she's pretty bright red, not burnt. Coolant flush is going to be next month, waiting till I buy an alldata membership for location of drains on the block. Also I'm changing the fuel filter today. hehehe she's keeping me busy I love this stuff. 

 

 

(Wasn't trying to double post, just decided to quote your response in hopes that you would see my question(s) for ya bud. Thanks

[Colossus]

Yes, the GM Dealer can do the top engine clean, in fact the stuff they use is really good stuff (GM top engine/induction cleaner) But a good independent repair facility can do it as well and probably for a lot less.  There are other good top engine cleaners as well.  The 2 shops I go to use BG and Justice Bros. products, they seem to do well, but I think BG does better.  They've been around a long time and have won over a lot of repair facilities because of the quality of their products.  The BG EPR that I mentioned earlier is one of their latest products and it is proving to work quite well, and they recently refined their 44K product to be more adventitious to direct injection engines that are more prone to carbon build up.  (your engine is not direct injection so that is ok but still a great additive I run twice a year regardless)  

 

 

[Black02Silverado]

Check your rear differential, it might have a drain plug.  My 2002 does and they discontinued it in 2003 but you might be lucky.  Check underneath it good because it sits flush with the bottom of the diff.   That way you wouldn't have to take the cover off unless you want to clean the magnet which would be a good idea and then just drain and fill there on after.

[Lsxtrucker]

36 minutes ago, Black02Silverado said:

Check your rear differential, it might have a drain plug.  My 2002 does and they discontinued it in 2003 but you might be lucky.  Check underneath it good because it sits flush with the bottom of the diff.   That way you wouldn't have to take the cover off unless you want to clean the magnet which would be a good idea and then just drain and fill there on after.

Yeah mine has no drain plug just a fill port. I'm going to pull the cover clean the magnet and replace the gasket anyways. Thanks for replying so quickly

[Lsxtrucker]

On 2/9/2020 at 8:47 PM, Colossus said:

Yes, the GM Dealer can do the top engine clean, in fact the stuff they use is really good stuff (GM top engine/induction cleaner) But a good independent repair facility can do it as well and probably for a lot less.  There are other good top engine cleaners as well.  The 2 shops I go to use BG and Justice Bros. products, they seem to do well, but I think BG does better.  They've been around a long time and have won over a lot of repair facilities because of the quality of their products.  The BG EPR that I mentioned earlier is one of their latest products and it is proving to work quite well, and they recently refined their 44K product to be more adventitious to direct injection engines that are more prone to carbon build up.  (your engine is not direct injection so that is ok but still a great additive I run twice a year regardless)  

 

 

Yes, I'd prefer to do it myself though. I looked into the Acdelco  engine clean per your suggestion and the process appears to be not terribly challenging. Luckily I'm very mechanically inclined, not to pat my own back but your tips are very useful. Thanks again. This is a great forum.  I also just bought a new trans filter and gasket (Delco ofcourse) along with 5 quarts of Dexron VI. It never ends but that's okay brother.

[Lsxtrucker]

Anyone know of a tutorial that covers the top engine cleaning procedure on our trucks in this case an '03?

[CamGTP]

Doubtful there is one. Nothing gets gummed these engines with port fuel injection. The fuel sprays right on the back side of the valve, so it's never dirty.

 

They don't have EGR after 2000/2001 so that's a non issue as well. If the PCV system so absolutely screwed then the intake would have some oil in it but that's about it.

 

I've had many NBS intakes off for gaskets and knock sensors, none of them needed a "top end engine cleaning".

[Lsxtrucker]

I erased this message to prevent duplicate posts. I started a new thread regarding the sputtering happening presently.