Hey guys. I've got a couple questions to ask about some regular maintenance questions for your GM V8's...

1.) What spark plugs and wires do you use and why?

My Yukon has 105k miles and I'm wanting to replace the plugs and wires now. I'd like to share, too, that whenever I called the local stealership, they said it would be about $300 to change plugs and wires...$300 just for plugs and wires. Why is this whenever I can go to autozone and get just about any platinum plug for around 2.50-3.00 a piece, and a set of wires for either 30 bucks or 60 bucks, depending on brand? A max of 100 bucks. That leaves $200 in labor? F*ck that.

2.) Would I see a milage improvement if I were to replace my rear oxygen sensor with a new one?

I was told that even replacing the one now (without a CEL) that I would see anywhere between 1 and 5mpg increase. I'm not sure how reliable that source is, but that's just what I've heard from a few people.

3.) This question isn't really maintenance, but it could potentially be a problem in the future. Under light throttle, I hear a sound that resembles change (coins) rattling coming from what sounds like the transmission. Now I was told that it could be the throwout bearing, but I thought only manual transmissions had throw-out bearings. Have you guys ever heard this? It started when the truck had about 75k miles, but it was really faint. It's gotten slightly louder now, and I was wondering if you guys had ever heard anything like that before. I had the tranny fluid changed about 3k miles ago, but it wasn't a complete flush. There's no slippage noted in the tranny itself, but it only makes that sound under light-moderate throttle. It doesn't make the sound at WOT. Any ideas? Oh yeh, stock 4l60e if you didn't know.

Thanks!

 

1) Use NGK TR55 spark plugs-proven performance and reliability
Spark plug wires are up to you, all brands seem to work just as well as the others.
2) Rear oxygen sensors monitor catalyst efficiency, your front O2 sensors determine fuel consumption. Definitely not a bad idea to change them at your mileage.
3) Sorry, no clue, but throw out bearings are only in manual trans'. Maybe loose heat shield, maybe catalytic converters.

 

It doesn't sound like an intermittent rattle. It's always there and always sounds the same at any RPM and any speed. I do believe it is in the transmission itself. It's been doing that for a while and hasn't had any problems, but sometimes it's annoying to listen to it. I'll see if I can get a sound clip one day...

 

bump it up...

anyone know the answer to my tranny question?

 

1) I would just change out the plugs and wires yourself and keep the rest in your pocket. I just did mine and I used the Delco Iridiums (AC 41-985's) I believe they were $6.99 each and the lifetime wires, I got everything from NAPA.

2) With over just over 100 thousand on the clock I would prolly replace all four O2's if you are worried about them.

3) Sounds like you might have some torque converter chatter, I have never experienced this but have heard of it. Might be an excuse to rebuild the tranny and put in a stall. Get with someone at FLT and see what they think it may be.

 

Awsome. I had too also heard it was the torque converter rattling. I'm glad I've heard it again, makes it sound a bit more believable. Thanks guys!

 

ive got 150k on stock plugs and wires with no problems

 

Yeh, I don't have any problems, but I just want to go ahead and replace them just for security reasons. It might even make it run better! I dunno, my biggest problem is the tranny. I don't need it to crap out on me if I'm on a long trip. Gonna be headin down to St. Pete Fl soon and don't need it to mess up!