120k maintenance tune up on 99 Denali

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triumph.man

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Thanks everyone! You guys saved me a lot of $$.

Thanks for the links sparg & sunlit.

another question...can all the replacements listed below be done @ home w/ just an open hood? I'm somewhat mechanically inclined, and I'm sure I can replace the plugs, cables, filter. But on the other notes, don't know what a distributor cap, ignition rotors are/located. I work on my motorcycle @ home and have the general tools needed.


This is truly a great forum, and going forward may start doing a lot of easy repairs on my own, minus the oil change... :)
 

sparg93

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yes, everything can be done with the hood open and a few tools.

Search tuneups on the forums and you will find a lot of tips and tricks.

Examples:
-Dielectric grease on the inside of the spark plug wire boots that connect to the spark plugs and the distributor.
-When taking the spark plugs out, BE VERY CAREFUL...if you strip it, you are going to spend a bit of money paying someone to take it out unless you know how to do it.
- Mark you wires and take your time so you know the order the plug wires connect to the spark plugs (search firing order) and distributor...or, just find a wiring diagram (i posted one about two weeks ago) and just pay attention to that. If your car doesn't run correctly after tuneup or you throw a check engine code, 9 out of 10 times you connected the wrong wire to the wrong plug
- you must torque the spark plugs correctly (i think it's 11lbs, BUT DOUBLE CHECK). i read somewhere these plugs are indexed so they work optimally at the appropriate torque setting...you will need a torque wrench for this (it's worth owning for other auto stuff as well)
- for plugs, spend the extra money on AC Delco premium
- Be careful when cleaning your MAF, you must use MAF cleaner...if you touch or disturb those thin pieces of metal with crud, say goodbye to your MAF...its VERY sensitive
- If your car calls for 41-993 spark plugs (which I believe it does), your gap is .06. Get a simple gapping tool (<$5) and verify the gap on each spark plug is the same. The premium plugs come pregapped but it is possible one may be off...so just confirm the gap before you install. When using the gap tool, be careful when measuring to not damage the tip of the electrode (pictures on the web showing how to check the gap)
- CAR MUST BE COLD WHEN DOING A TUNEUP - you're going to be touching a lot of parts that typically get very hot, so I usually perform my tuneups in the morning.


So, net net - do some research and have print outs available for you to reference when you perform your first tune-up. After you do it the first time, it's really easy afterwards....just remember to take your time and don't break anything when you get aggravated. :)

Also, cover your fender with a mat or towels etc...if not, you'll scratch the hell out of your fenders performing this tuneup.

The other items such as servicing your trans, rear diff and front - save those items for another day and really make sure you know what you're doing...even though straight forward, mistakes can be rather expensive around those parts.

Welcome to the forum - a lot of friendly people on here that are always willing to offer advice. My recommendation is ALWAYS confirm opinions b/c every now and then good intentioned advice may be incorrect...I know I have accidentally give inaccurate advice before...so always double check and verify what you read!!
 

SunlitComet

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You could also get some repair maintenance data from Autozone online. Or get yourself a manual from the local parts store. You certainly have money for it now.:)

---------- Post added at 09:50 AM ---------- Previous post was at 09:48 AM ----------

Also the cap and I think the rotor too uses a torx bit for the screws so if you don't have one take one of the new screw and get one that matches. I don't remember the size though.
 
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triumph.man

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just ordered me the spark plugs and wires....gonna do it piece by piece. This part alone saved me +$400 :)

thanks sparg for the great detailed info!

one other question. your refer "that you must torque the spark plugs correctly (15lbs)." how do I measure this w/ a torque wrench? i have several torque wrenches but no measuring system on them (if this makes any sense)...is there a tool that measures this? googled it, but found no info.
 

sparg93

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this is a torque wrench:
http://mtobikes.com/wp-content/uploads/torque-wrench-handle-adjustment.jpg

at the bottom is a knob the individual is turning, this is setting the desired torque setting on the wrench (you can see the number towards the top of the photo).

The idea is that when you set the torque wrench to 11lbs, it will "click" as you reach the 11lb limit as you are tightening the plug. When you hear/feel the click, stop tightening.

There are a few styles of torque wrenches out there, but they all have numbers somewhere indicating their settings. Also, if the torque wrench is old or not taken care of (i.e. thrown around), there is a good chance it will not be as precise as it used to be out of the factory.

Not too big of a deal for 100lb load when installing tires, but if you're a few lbs off when installing spark plugs, it may affect performance.

Also, coat the part of the spark plug (threads) that enters the engine block with anti-seize...it's a silvery material that can be purchased at any auto parts store. Anti seize should ONLY go on the threads, nowhere else on the spark plug.

A quick writeup on spark plugs and the influence of torque:
http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp
 

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