We’ve had the A8 for almost 4 years and added 40k miles, it’s been the most comfortable & reliable car we’ve ever had (and we have never taken it to the dealers or shops for anything except alignment & new tires). According to the ex-owner records, the spark plugs are over 60k miles old. With the gas prices is hitting close to ~$4 /gallon, it’s time for us to tune up my A8, although it’s still running solidly. We ordered 8 copper spark plugs from Autohausaz a few months back, we didn’t want to get the platinum although it’s only a few cents difference. On Saturday 3/8/08 with odo @ 144xxx miles, it’s the first time we’ve touched the engine compartment.
Everything is sealed and covered so nicely. In order to get to the 8 spark plugs, we needed to remove 2 covers using 5mm hex key, we can see the 2 hex bolts on each side next to the 4 Audi rings. The one on the left, need the air cleaner hose removed to lift the cover out.
After the cover is removed, we was amazed at the spark plug wires & coils positions, so beautifully placed.
10 mm socket is needed to remove the spark plug cover and remove it slowly and carefully.
Since the socket is deep, we used 6″ extension (I didn’t want to use 9″ because it’s a little long and we don’t want to wiggle too much) and a little force over 22ft/lb by specs to remove the spark plug. WE DID ONE AT A TIME.
This is how a 60k copper spark plug in a good V8 look like, still nice looking, it’s dark because we didn’t warm up the car when moving it out of the garage.
Before we install the new spark plug, we inspected all the 4 electrodes and gaps to make sure they’re not damaged from the factory and we always put some new engine oil around the thread to make sure it goes in smoothly thread by thread.
It’s aluminum head, so we have to hand twist all spark plugs in thread by thread slowly but surely until they go in all the way. The torque wrench is only used for the last thread and tighten only. Don’t over tighten the spark plug if you don’t have the torque wrench, don’t strip or break anything. FINISH ONE and MOVE TO THE NEXT SLOWLY and CAREFULLY!!!!
While the Air cleaner hose is out, we also bought an air filter to replace it with. We used the high pressure hose to blow out all the dirt, since there is no Oil, there’s no grimes on the air filter.
To remove the old air filter, we need to unscrew 4 screws securing the cover, it’s very easy to remove when the screws are done. We vacuumed the bottom part to be cleaned from sands and bugs before placing the new air filter in.
While the Air cleaner is out, we can see the throttle body was so dirty, remove the rubber connector and use a clean rag sprayed with carburetor cleaner and let the fingers do the wiggling and wiping, clean the butterflies and body as much as you can. I don’t spray anything into the throttle body.
Put everything back and ready to start the car to see if it runs. It did like it should… The idle and acceleration is much smoother and the engine is quieter during acceleration. It did make some difference or may be it’s just my feelings? Anyhow, time will tell, my wife will give me a full report on the gas mileage. She did say the engine seems to operate better.
While every covers were removed, I took my time to inspect all the rubber hoses, and they’re all good. Believe it or not, these vacuum hoses could cause your car to idle and run so bad that you may have to get a tune up for 1000s of dollars and still wouldn’t fix it. This is an example of what a tune up can do, NOT MUCH, with 60k miles old spark plugs, our car still runs great, so next time if your car doesn’t start, idles bad, or sluggish in acceleration, check something else, like electrical connection or VACUUM HOSES I heard people also change fuel pump, fuel filter. In all my life driving older cars, I never had to replace one fuel pump or fuel filter… or another one, clogged air cleaner… look at my air filter please, how bad did it look and it didn’t stop my car from running fine.
Cheers and hope your cars run well,