Ill do. I've never changed plugs on a car. Will it be difficult? I've heard things like plugs cracking and stripping before and I definitely don't want to be replacing a head. Especially being almost 15 years old. And should I use anti-sieze or no? Would this be something better to just let the mechanic do?

 

I cant speak to your mechanical ability, but it is generally not a difficult job. I would remove the inner fenders to make access much easier. I would advise against using any power or air tools. You will have to have a little finesse. Remove plug wires and take care not to crush the metal boot on the wire that connects to the plug, you will reuse this on the new wire. Removing plugs is self explanatory. Reinstalling, I do not use typically anti-seize, is where you will need to have the most finesse. You want to make sure you can thread them in square to the threads and not cross-threaded. Make sure it threads in a few threads by hand easily before ratcheting. The plugs really don't ever seize or strip in the head on this motor; thats really a ford thing. Make sure you buy OEM plugs and inspect the porcelain for cracks and make sure the electrode is not crushed before installing.

Its a pretty straight forward job if you are patient. Take pictures and post of the old plugs.

 

Red plug wires are definitely not factory. Make sure to only use ACDelco spark plugs specified for your engine. They just work.

 

Ok. They might be different factory on 08, but I didn’t think so either. I’m sure I could look it up.

I think I’m gonna have my mechanic just do it for me. I don’t have the time to mess with it.

I’m recording data right now so I should have it all synced together and uploaded in a few hours.

 

Just finished...
Fuel Trim(hill is at 1:01) - https://drive.google.com/file/d/1Y3K...ew?usp=sharing
Temperatures(1:44 here) - https://drive.google.com/file/d/1Pu1...ew?usp=sharing
(also threw in rpm and MAP sensor)

This is not the same place as where the last data was taken. This was on a little bit bigger hill. The first video I turn onto the main road, then turn onto the road with the hill. Immediately after I turn into the gas station that connects the two roads and go up the hill a second time. Then there should be a portion at wot.

Second video I turn on the main road then turn left to go up the hill. Then I'm pretty sure I turn around in a parking lot and go up the other side of the hill. I can't remember if I included that part or not.
Just trying to give as much context as I can.

Also on the 08s the plug wires are red from the factory, so I'm almost certain plugs have never been changed. Hopefully it is just plugs. It's got to go in to have the door lock replaced anyway. I gave them the wrong part by accident. They got the door apart, then didn't reconnect anything so my switches don't work. Part took a week to get here. So Ill just have them look at plugs and wires, carbon buildup, and the egr system while its there. Im placing my bets on plugs.

Thanks for all the help.

 

Yes, GM used the red wires19351593 on the 2 & 3 only in '08 before chapter 11 reorganization.

Part Fitment

Year Make Model Engine Important vehicle option details 2008 Buick Allure 8 Cyl 5.3L CX (US)/ALLURE CX (CAN), CX 4 DOOR, CXL 4 DOOR, CXL(US)/ALLURE CXL(CAN), CXS 4 DOOR, CXS(US)/Allure CXS(CAN), SUPER SERIES 4 DOOR 2008 Buick LaCrosse 8 Cyl 5.3L CX (US)/ALLURE CX (CAN), CX 4 DOOR, CXL 4 DOOR, CXL(US)/ALLURE CXL(CAN), CXS 4 DOOR, CXS(US)/Allure CXS(CAN), SUPER SERIES 4 DOOR 2005-2007 Buick Rainier 8 Cyl 5.3L 4 DOOR 2006-2007 Cadillac CTS 8 Cyl 6.0L V 4 DOOR 2007-2008 Cadillac Escalade 8 Cyl 6.2L 1/2 TON, EXT 1/2 TON, YUKON XL/DENALI XL/ESCALADE ESV, YUKON/DENALI/ESCALADE 2007-2008 Chevrolet Avalanche 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L 1/2 TON 2005-2008 Chevrolet Corvette 8 Cyl 6.0L, 8 Cyl 6.2L, 8 Cyl 7.0L 2 DOOR, 2 DOOR SPECIAL, CONVERTIBLE 2008 Chevrolet Express 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 6.0L 1 TON CARGO EXPRESS, 1 TON COMMERCIAL/RECREATIONAL VEHICLE EXPRESS, 1 TON PASSENGER, 1/2 TON CARGO EXPRESS, 1/2 TON PASSENGER EXPRESS, 3/4 TON CARGO EXPRESS, 3/4 TON PASSENGER EXPRESS 2006-2008 Chevrolet Impala 8 Cyl 5.3L LS, LS POLICE CAR, LT, LT 3.5, LTZ, SS 2006-2007 Chevrolet Monte Carlo 8 Cyl 5.3L LS, LT, SS 2005-2006 Chevrolet SSR 8 Cyl 6.0L SPORT TRUCK 2007-2008 Chevrolet Silverado 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L CREW CAB 1 TON, CREW CAB 1/2 TON, CREW CAB 6'6" BOX 3/4 TON, CREW CAB 8' BOX 3/4 TON, EXTENDED CAB 1 TON, EXTENDED CAB 5'8" BOX 1/2 TON, EXTENDED CAB 6'6" BOX 1/2 TON, EXTENDED CAB 6'6" BOX 3/4 TON, EXTENDED CAB 8' BOX 1/2 TON, EXTENDED CAB 8' BOX 3/4 TON, EXTENDED CAB CHASSIS 1 TON 161.5, REGULAR CAB 1 TON, REGULAR CAB 3/4 TON, REGULAR CAB 6'6" BOX 1/2 TON, REGULAR CAB 8' BOX 1/2 TON, REGULAR CAB CHASSIS 1 TON 137.0, REGULAR CAB CHASSIS 1 TON 161.5 2007-2008 Chevrolet Suburban 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L 1/2 TON, 3/4 TON 2007-2008 Chevrolet Tahoe 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L 4 DOOR 1/2 TON 2005-2008 Chevrolet Trailblazer 8 Cyl 5.3L, 8 Cyl 6.0L 4 DOOR, 4 DOOR EXT 2005-2008 GMC Envoy 8 Cyl 5.3L 4 DOOR, 4 DOOR EXT, 4 DOOR XUV 2008 GMC Savana 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 6.0L 1 TON CARGO EXPRESS, 1 TON CARGO SAVANA, 1 TON COMMERCIAL/RECREATIONAL VEHICLE SAVANA, 1 TON PASSENGER, 1/2 TON CARGO EXPRESS, 1/2 TON CARGO SAVANA, 1/2 TON PASSENGER EXPRESS, 1/2 TON PASSENGER SAVANA, 3/4 TON CARGO EXPRESS, 3/4 TON CARGO SAVANA, 3/4 TON PASSENGER EXPRESS, 3/4 TON PASSENGER SAVANA, VAN 1 TON COMMERCIAL/RV CUTAWAY 2007-2008 GMC Sierra 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L, 8 Cyl 6.2L CREW CAB 1 TON, CREW CAB 1/2 TON, CREW CAB 6'6" BOX 3/4 TON, CREW CAB 8' BOX 3/4 TON, EXTENDED CAB 1 TON, EXTENDED CAB 5'8" BOX 1/2 TON, EXTENDED CAB 6'6" BOX 1/2 TON, EXTENDED CAB 6'6" BOX 3/4 TON, EXTENDED CAB 8' BOX 1/2 TON, EXTENDED CAB 8' BOX 3/4 TON, EXTENDED CAB CHASSIS 1 TON 161.5, REGULAR CAB 1 TON, REGULAR CAB 3/4 TON, REGULAR CAB 6'6" BOX 1/2 TON, REGULAR CAB 8' BOX 1/2 TON, REGULAR CAB CHASSIS 1 TON 137.0, REGULAR CAB CHASSIS 1 TON 161.5 2007-2008 GMC Yukon 8 Cyl 4.8L, 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L, 8 Cyl 6.2L 1/2 TON, 3/4 TON, XL 3/4 TON, YUKON XL/DENALI XL/ESCALADE ESV, YUKON/DENALI/ESCALADE 2008 Hummer H2 8 Cyl 6.2L PICKUP, SUV 2008 Hummer H3 8 Cyl 5.3L SUV 2005-2006 Pontiac GTO 8 Cyl 6.0L GTO 2005-2008 Pontiac Grand Prix 8 Cyl 5.3L 4 DOOR, GT 4 DOOR, GT2 4 DOOR, GTP

 

Do you know if the 08s have an EGR system? I Don't see any valve around the engine for that and can't find any parts for an egr system online. My scanner also doesn't show an option to read EGR Data which I think it would if it was available.


Edit: Also I did some poking looking for the egr valve. Looked at the vacuum side of the supercharger and found there is a hose that is slightly loose without a hose clamp that goes to some plastic thing on the drivers side of the engine above the coils. There is another line that goes to the top of the valve cover(I assume something with the pcv system. It says pcv on the line if that means anything) that is wet with oil. Not dripping but noticeably wet. Not sure how to fix that since it doesn’t seem loose.

Here is a video - https://drive.google.com/file/d/1yKwF2ZHicWWNCj3J8GXNPOOmy8cC1ECC/view?usp=drivesdk

 

EVAP purge solenoid

 

No egr valve, yet required on engines with high combustion temp since NOx (nitrogen oxide) gets created when the temperature inside the engine's combustion chamber exceeds 2,500 degrees Fahrenheit.

 

I don't see a catch can in the PCV line which can cause a lot of issues on a boosted engine especially an LS engine. The valve cover baffles are known to be sub par for the job they are meant to do. Its likely if you were to pull that line off the vacuum port it will be full of oil along with the blower and intake. GM recommends the replacement of the driver side valve cover with a new one when oil is noticed in the intake. Mine had over a quart of oil in the intake when I pulled it and there is no easy way to get it out. If the PCV is passing oil to the engine it can contribute to the noise your hearing, not saying this is your issue but it can be.

Have you had to add oil to the engine?

Neal